AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON OCTOBER 11, 2001
                                            REGISTRATION NO. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-3
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                             SOUTHWEST AIRLINES CO.
             (Exact name of registrant as specified in its charter)

                     TEXAS                                    741563240
(State or other Jurisdiction of                            (I.R.S. Employer
 Incorporation or Organization)                         Identification Number)

                     2702 Love Field Drive, Dallas, TX 75235
                                  214/792-4000
               (Address, Including Zip Code, and Telephone Number,
        Including Area Code, of Registrant's Principal Executive Offices)

                                  LAURA WRIGHT
                     Vice President - Finance and Treasurer
                             Southwest Airlines Co.
                     2702 Love Field Drive, Dallas, TX 75235
                                  214/792-4459
                (Name, address, including zip code, and telephone
               number, including area code, of agent for service)


                          COPIES OF CORRESPONDENCE TO:

                                DEBORAH ACKERMAN
                        Vice President - General Counsel
                             Southwest Airlines Co.
                     2702 Love Field Drive, Dallas, TX 75235
                                  214/792-4665

      Approximate date of commencement of proposed sale to the public: From time
to time after the effective date of this Registration Statement.

      If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, check the following box.[ ]

      If any of the securities being registered on this Form are to be offered
on a delayed or continuous basis pursuant to Rule 415 under the Securities Act
of 1933, other than securities offered only in connection with dividend or
interest reinvestment plans, check the following box. [X]

      If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]

      If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [ ]

      If delivery of the prospectus is expected to be made pursuant to Rule 434,
check the following box. [ ]

                         CALCULATION OF REGISTRATION FEE



----------------------------------------------------------------------------
----------------------------------------------------------------------------
                                         PROPOSED MAXIMUM
TITLE OF EACH CLASS OF SECURITIES       AGGREGATE OFFERING      AMOUNT OF
       TO BE REGISTERED                       PRICE*        REGISTRATION FEE
----------------------------------------------------------------------------
                                                      
Debt Securities and
  Pass Through Certificates............   $1,000,000,000       $250,000
----------------------------------------------------------------------------
----------------------------------------------------------------------------


* Estimated solely for purposes of determining the registration fee pursuant to
Rule 457(o) under the Securities Act of 1933.

      THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.

                                EXPLANATORY NOTE

      This Registration Statement contains two separate forms of prospectuses to
be used in connection with offerings of Debt Securities and Pass Through
Certificates.

                 SUBJECT TO COMPLETION, DATED October 11, 2001

                                   PROSPECTUS
                             SOUTHWEST AIRLINES CO.
                                 DEBT SECURITIES

      This prospectus relates to the issuance of unsecured debt securities by
Southwest Airlines Co.

                          ISSUANCE OF DEBT SECURITIES:

      -     Series may be periodically offered; and

      -     Prices and terms will be determined at the time of sale.

      The total aggregate principal amount (or, in the case of debt securities
issued at a discount, the initial offering price) will not exceed US
$1,000,000,000.

                      FORMS THAT DEBT SECURITIES MAY TAKE:

      -     Registered form; or

      -     Global form.

      This prospectus is accompanied by a prospectus supplement which includes
additional information as to a particular series of debt securities. Sales of
debt securities may not be consummated without both this prospectus and a
prospectus supplement.

                 INFORMATION FOUND IN THE PROSPECTUS SUPPLEMENT:

      -     Aggregate principal amount of the series of debt securities

      -     Denominations

      -     Maturity

      -     Interest rate

      -     Time of interest payments

      -     Any terms for redemption

      -     Any terms for sinking fund payments

      -     Any listing on a national securities exchange

      -     Initial public offering price

      -     Names of any underwriters or agents

      -     Terms of any underwriting arrangements

      -     Amounts to be purchased by underwriters or agents

      -     Compensation of underwriters or agents

      NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED THAT
THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

      THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE
MAY NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER
TO SELL SECURITIES AND IT IS NOT SOLICITING AN OFFER TO BUY SECURITIES IN ANY
STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.

           The date of this prospectus is ______________________, 2001



                                TABLE OF CONTENTS
                                                                        PAGE
                                                                    
About This Prospectus...............................................       i
Southwest Airlines Co...............................................       1
Use of Proceeds.....................................................       1
Ratios of Earnings to Fixed Charges.................................       1
Description of Debt Securities Southwest May Offer..................       2
Plan of Distribution................................................      11
Validity of the Debt Securities.....................................      12
Experts.............................................................      12
Where You Can Find More Information.................................      13


      You should rely only on the information contained in this prospectus or
any prospectus supplement or information contained in documents which you are
referred to in this prospectus or any prospectus supplement. Southwest has not
authorized anyone to provide you with information different from that contained
in this prospectus or any prospectus supplement. Southwest is offering to sell
the debt securities only in jurisdictions where offers and sales are permitted.
The information contained in this prospectus or any prospectus supplement is
accurate only as of the date on the front of those documents, regardless of the
time of delivery of the documents or any sale of the debt securities.

                              ABOUT THIS PROSPECTUS

      This prospectus is part of a registration statement that Southwest filed
with the Securities and Exchange Commission utilizing a shelf registration
process. Under this shelf process, Southwest may sell the securities described
in this prospectus in one or more offerings up to a total offering amount of
$1,000,000,000. This prospectus provides you with a general description of the
debt securities Southwest may offer.

      Each time Southwest sells debt securities, Southwest will provide a
prospectus supplement that will contain specific information about the terms of
that offering. The prospectus supplement may also add, update or change
information contained in this prospectus. You should read both this prospectus
and any prospectus supplement together with additional information described in
the section entitled "Where You Can Find More Information."

      In this prospectus, references to "Southwest," "we," "us" and "our" mean
Southwest Airlines Co.


                                       (i)

                             SOUTHWEST AIRLINES CO.

      Southwest Airlines Co. is a major domestic airline which provides single
class air transportation characterized by frequent, high quality service at
affordable prices. Our service primarily appeals to the business commuter as
well as the leisure traveler. Southwest Airlines began serving Customers in 1971
with three Boeing 737 aircraft serving three cities. As of September 30, 2001,
Southwest operated 358 Boeing 737 aircraft and provided service to 58 airports
in 57 cities in 29 states throughout the United States. Please refer to the
Section "Where You Can Find More Information" to learn more about Southwest
Airlines.

      Our principal executive offices are located at 2702 Love Field Drive, P.O.
Box 36611, Dallas, Texas 75235, and our telephone number is (214) 792-4000.
Southwest is incorporated under the laws of the State of Texas.

                                 USE OF PROCEEDS

      Southwest intends to use the net proceeds from the sale of the debt
securities offered hereby for general corporate purposes, unless otherwise
specified in the prospectus supplement relating to a specific issuance of debt
securities. Such general corporate purposes may include, among other possible
uses, the repayment of short-term or long-term indebtedness and capital
expenditures.

                       RATIOS OF EARNINGS TO FIXED CHARGES

      The following table sets forth the historical ratios of earnings to fixed
charges of Southwest for the periods indicated:



SIX MONTHS ENDED
     JUNE 30,                         YEAR ENDED DECEMBER 31,
----------------        ----------------------------------------------------
                                                      
2000        2001        1996        1997        1998        1999        2000
----        ----        ----        ----        ----        ----        ----
5.56        5.77        2.73        3.50        4.58        5.01        5.97


      Earnings represent:

      -     Income before income taxes, excluding the cumulative effect of
accounting changes; plus

      -     Fixed charges, excluding capitalized interest.

      Fixed charges include:

      -     Interest, whether expensed or capitalized; and

      -     A portion of rental expense. Management of Southwest believes this
is representative of the interest factor in those periods.


                                       1

               DESCRIPTION OF DEBT SECURITIES SOUTHWEST MAY OFFER

      As required by federal law for all bonds and notes of companies that are
publicly offered, the debt securities are governed by a document called the
indenture. The indenture is a contract, dated as of February 25, 1997, between
Southwest and U.S. Trust Company of Texas, N.A., which acts as trustee.

      The trustee has two main roles. First, the trustee can enforce your rights
against us if we default. There are some limitations on the extent to which the
trustee acts on your behalf, described under "Remedies If an Event of Default
Occurs." Second, the trustee performs administrative duties for us, such as
sending you interest payments, transferring your debt securities to a new buyer
if you sell and sending you notices.

      The indenture and its associated documents contain the full legal text of
the matters described in this section. The indenture and the debt securities are
governed by Texas law. A copy of the indenture may be obtained from Southwest as
described below under "Where You Can Find More Information."

      Southwest may issue as many distinct series of debt securities under the
indenture as it wishes.

      This section summarizes the material terms of the debt securities that are
common to all series, although the prospectus supplement which describes the
terms of each series of debt securities may also describe differences with the
material terms summarized here.

      Because this section is a summary, it does not describe every aspect of
the debt securities. This summary is subject to and qualified in its entirety by
reference to all the provisions of the indenture, including definitions of
certain terms used in the indenture. In this summary, Southwest describes the
meaning for only the more important terms. You must look to the indenture for
the most complete description of what Southwest describes in summary form in
this prospectus.

      This summary also is subject to and qualified by reference to the
description of the particular terms of your series described in the prospectus
supplement. Those terms may vary from the terms described in this prospectus.
The prospectus supplement relating to each series of debt securities will be
attached to the front of this prospectus. There may also be a further prospectus
supplement, known as a pricing supplement, which contains the precise terms of
debt securities you are offered.

      Southwest may issue the debt securities as original issue discount
securities, which will be offered and sold at a substantial discount below their
stated principal amount. The prospectus supplement relating to the original
issue discount securities will describe federal income tax consequences and
other special considerations applicable to them. The prospectus supplement
relating to specific debt securities will also describe any special
considerations and certain additional tax considerations applicable to such debt
securities.

      In addition, the specific financial, legal and other terms particular to a
series of debt securities are described in the prospectus supplement and any
pricing supplement relating to the


                                       2

series. The prospectus supplement relating to a series of debt securities will
describe the following terms of the series:

      -     the title of the series of debt securities;

      -     any limit on the aggregate principal amount of the series of debt
securities;

      -     the person to whom interest on a debt security is payable, if other
than the holder on the regular record date;

      -     the date or dates on which the series of debt securities will
mature;

      -     the rate or rates, which may be fixed or variable, per annum at
which the series of debt securities will bear interest, if any, and the date or
dates from which that interest, if any, will accrue;

      -     the place or places where the principal of (and premium, if any) and
interest on the debt securities are payable;

      -     the dates on which interest, if any, on the series of debt
securities will be payable and the regular record dates for the interest payment
dates;

      -     any mandatory or optional sinking funds or similar provisions or
provisions for redemption at the option of the issuer;

      -     the date, if any, after which and the price or prices at which the
series of debt securities may, in accordance with any optional or mandatory
redemption provisions, be redeemed and the other detailed terms and provisions
of those optional or mandatory redemption provisions, if any;

      -     if other than denominations of $1,000 and any of its integral
multiples, the denominations in which the series of debt securities will be
issuable;

      -     the applicability of the provisions described under "Defeasance;"

      -     if the series of debt securities will be issuable only in the form
of a global security, the depository or its nominee with respect to the series
of debt securities and the circumstances under which the global security may be
registered for transfer or exchange in the name of a person other than the
depositary or the nominee; and

      -     any other special feature of the series of debt securities.

LEGAL OWNERSHIP

      Street Name and other Indirect Holders. Investors who hold debt securities
in accounts at banks or brokers will generally not be recognized by us as legal
holders of debt securities. This is called holding in street name. Instead,
Southwest would recognize only the bank or broker, or the financial institution
the bank or broker uses to hold its debt securities. These intermediary banks,


                                       3

brokers and other financial institutions pass along principal, interest and
other payments on the debt securities, either because they agree to do so in
their customer agreements or because they are legally required to. If you hold
debt securities in street name, you should check with your own institution to
find out:

      -     how it handles securities payments and notices;

      -     whether it imposes fees or charges;

      -     how it would handle voting if required;

      -     whether and how you can instruct it to send you debt securities
registered in your own name so that you can be a direct holder as described
below; and

      -     how it would pursue rights under the debt securities if there were a
default or other event triggering the need for holders to act to protect their
interests.

      Direct Holders. Our obligations, as well as the obligations of the trustee
and those of any third parties employed by Southwest or the trustee, run only to
persons who are registered as holders of debt securities. As noted above,
Southwest does not have obligations to you if you hold debt securities in street
name or other indirect means, either because you choose to hold debt securities
in that manner or because the debt securities are issued in the form of global
securities as described below. For example, once we make payment to the
registered holder, we have no further responsibility for the payment, even if
that holder is legally required to pass the payment along to you as a street
name customer but does not do so.

GLOBAL SECURITIES

      What is a Global Security? A global security is a special type of
indirectly held security, as described above under "Street Name and Other
Indirect Holders." If Southwest chooses to issue debt securities in the form of
global securities, the ultimate beneficial owners can only be indirect holders.
Southwest does this by requiring that the global security be registered in the
name of a financial institution it selects and by requiring that the debt
securities included in the global security not be transferred to the name of any
other direct holder unless the special circumstances described below occur. The
financial institution that acts as the sole direct holder of the global security
is called the depositary. Any person wishing to own a debt security must do so
indirectly by virtue of an account with a broker, bank or other financial
institution that in turn has an account with the depositary. The prospectus
supplement indicates whether your series of securities will be issued only in
the form of global securities.

      Special Investor Considerations for Global Securities. As an indirect
holder, an investor's rights relating to a global security will be governed by
the account rules of the investor's financial institution and of the depositary,
as well as general laws relating to securities transfers. We do not recognize
this type of investor as a holder of debt securities and instead deal only with
the depositary that holds the global security.


                                       4

           If you are an investor, you should be aware that if debt securities
are issued only in the form of global securities:

      -     You cannot get debt securities registered in your own name.

      -     You cannot receive physical certificates for your interest in the
debt securities.

      -     You will be a street name holder and must look to your own bank or
broker for payments on the debt securities and protection of your legal rights
relating to the debt securities. See "Legal Ownership -- Street Name and Other
Indirect Holders."

      -     You may not be able to sell interests in the debt securities to some
insurance companies and other institutions that are required by law to own their
securities in the form of physical certificates.

      -     The depositary's policies will govern payments, transfers, exchange
and other matters relating to your interest in the global security. Southwest
and the trustee have no responsibility for any aspect of the depositary's
actions or for its records of ownership interest in the global security.
Southwest and the trustee also do not supervise the depositary in any way.

      Special Situations when Global Security will be Terminated. In a few
special situations described in the next paragraph, the global security will
terminate and interests in it will be exchanged for physical certificates
representing debt securities. After that exchange, the choice of whether to hold
debt securities directly or in street name will be up to you. You must consult
your own bank or broker to find out how to have your interests in debt
securities transferred to our own name, so that you will be a direct holder. The
rights of street name investors and direct holders in the debt securities have
been previously described in the subsections entitled "Street Name and Other
Indirect Holders" and "Direct Holders."

      The special situations for termination of a global security are:

      -     When the depositary notifies Southwest that it is unwilling, unable
or no longer qualified to continue as depositary and a successor depositary is
not appointed by Southwest within 90 days.

      -     When Southwest notifies the trustee that it wishes to terminate the
global security.

      -     When an event of default on the securities has occurred and has not
been cured, disregarding for this purpose any requirement of notice or that the
default exists for a specified period of time. (Default is discussed later under
"Events of Default")

      The prospectus supplement may also list additional situations for
terminating a global security that would apply only to the particular series of
debt securities covered by the prospectus supplement. When a global security
terminates, the depositary (and not Southwest or the trustee) is responsible for
deciding the names of the institutions that will be the initial direct holders.

      IN THE REMAINDER OF THIS DESCRIPTION "YOU" MEANS DIRECT HOLDERS AND NOT
STREET NAME OR OTHER INDIRECT HOLDERS OF DEBT SECURITIES.


                                       5

INDIRECT HOLDERS SHOULD READ THE PREVIOUS SUBSECTION ENTITLED "STREET NAME AND
OTHER INDIRECT HOLDERS."

OVERVIEW OF REMAINDER OF THIS DESCRIPTION

      The remainder of this description summarizes:

      -     ADDITIONAL MECHANICS relevant to the debt securities under normal
circumstances, such as how you transfer ownership and where Southwest makes
payments;

      -     Your rights in several SPECIAL SITUATIONS, such as if Southwest
merges with another company, or if Southwest wants to change a term of the debt
securities;

      -     A DEFEASANCE clause, which may allow for Southwest to be completely
released from its payment and other obligations on the debt securities; and

      -     Your rights if Southwest DEFAULTS or experiences other financial
difficulties.

ADDITIONAL MECHANICS

      Form, Exchange and Transfer. The debt securities will be issued:

      -     only in fully registered form;

      -     without interest coupons; and

      -     in denominations that are even multiples of $1,000.

      You may have your debt securities divided into more debt securities of
smaller denominations or combined into fewer debt securities of larger
denominations, as long as the total principal amount is not changed. This is
called an exchange.

      You may exchange or transfer debt securities at the office of the trustee.
The trustee acts as Southwest's agent for registering debt securities in the
names of holders and transferring debt securities. Southwest may change this
appointment to another entity or perform these functions itself. The entity
performing the role of maintaining the list of registered holders is called the
security registrar. It will also perform transfers.

      You will not be required to pay a service charge to transfer or exchange
debt securities, but you may be required to pay for any tax or other
governmental charge associated with the exchange or transfer. The transfer or
exchange will only be made if the security registrar is satisfied with your
proof of ownership.

      If Southwest has designated additional transfer agents, they are named in
the prospectus supplement. Southwest may cancel the designation of any
particular transfer agent. Southwest may also approve a change in the office
through which any transfer agent acts.


                                       6

      If the debt securities are redeemable, Southwest may block the transfer or
exchange of debt securities for a period beginning 15 days before the day
Southwest mails the notice of redemption, in order to freeze the list of holders
to prepare the mailing. Southwest may also refuse to register transfers or
exchanges of debt securities selected for redemption, except that Southwest will
continue to permit transfers and exchanges of the unredeemed portion of any debt
security being partially redeemed.

      Payment and Paying Agents. Southwest will pay interest to you if you are a
direct holder listed in the trustee's records at the close of business on a
particular day in advance of each due date for interest, even if you no longer
own the debt security on the interest due date. That particular day, usually
about two weeks in advance of the interest due date, is called the regular
record date and is stated in the prospectus supplement. Holders buying and
selling debt securities must work out between them how to compensate for the
fact that Southwest will pay all the interest for an interest period to the one
who is the registered holder on the regular record date. The most common manner
is to adjust the sales price of the securities to pro rate interest fairly
between buyer and seller. This prorated interest amount is called accrued
interest.

      Southwest will pay interest, principal and any other money due on the debt
securities at the corporate trust office of the trustee in Dallas, Texas. That
office is currently located at 2001 Ross Avenue, Suite 2700, Dallas, Texas
75201. You must make arrangements to have your payments picked up at or wired
from that office. Southwest may also choose to pay interest by mailing checks.

      STREET NAME AND OTHER INDIRECT HOLDERS SHOULD CONSULT THEIR BANKS, BROKERS
OR OTHER FINANCIAL INSTITUTIONS FOR INFORMATION ON HOW THEY WILL RECEIVE
PAYMENTS.

      Southwest may also arrange for additional payment offices, and may cancel
or change these offices, including its use of the trustee's corporate trust
office. These offices are called paying agents. Southwest may also choose to act
as its own paying agent. Southwest must notify you of changes in the paying
agents for any particular series of debt securities.

      Notices. Southwest and the trustee will send notices regarding the debt
securities only to direct holders, using their addresses as listed in the
trustee's records.

      Regardless of who acts as paying agent, all money paid by Southwest to a
paying agent that remains unclaimed at the end of two years after the amount is
due to direct holders will be repaid to Southwest. After that two-year period,
you may look only to Southwest for payment and not to the trustee, any other
paying agent or anyone else.

SPECIAL SITUATIONS

      Mergers and Similar Events. Southwest is generally permitted to
consolidate or merge with another corporation. We are also permitted to sell or
convey all or substantially all of our assets to another corporation. However,
we may not take any of these actions unless all of the following conditions are
met:


                                       7

      Where Southwest consolidates or merges out of existence or sells or
conveys all or substantially all of its assets, the other corporation must be
organized under the laws of a state or under federal law, and it must agree to
be legally responsible for the debt securities.

      Immediately after the merger, sale of assets or other transaction
Southwest must not be in default on the debt securities. A default for this
purpose would also include any event that would be an event of default if the
requirements for giving Southwest default notice or Southwest's default having
to exist for a specific period of time were disregarded.

MODIFICATION AND WAIVER

      There are three types of changes Southwest can make to the indenture and
the debt securities.

      Changes Requiring Your Approval. First, there are changes that cannot be
made to your debt securities without your specific approval. Following is a list
of those types of changes:

      -     extend the stated maturity of the principal or interest on a debt
security;

      -     reduce any amounts due on a debt security;

      -     reduce the amount of principal payable on an original discount
security upon acceleration of the maturity of the debt security following a
default;

      -     impair your right to sue for payment; and

      -     reduce the percentage of the principal amount of debt securities of
any series or all series (voting as one class) the consent of which is needed to
modify or amend the indenture;

      Changes Requiring a Vote. The second type of change to the indenture and
the debt securities is the kind that requires a vote in favor by the holders of
debt securities owning at least 66 2/3% of the principal amount of the
particular series affected. Most changes fall into this category, except for
clarifying changes and certain other changes that would not adversely affect the
interest of holders of the debt securities described in the next paragraph.
Southwest may obtain a waiver of a past default from the holders of debt
securities owning a majority of the principal amount of the particular series
affected. However, Southwest cannot obtain a waiver of a payment default unless
Southwest obtains an individual consent to the waiver from every holder.

      Changes Not Requiring Approval. The third type of change to the indenture
and the debt securities does not require any vote by holders of debt securities.
This type is limited to clarifications and certain other changes that would not
adversely affect the interests of holders of the debt securities. Holders of
debt securities will also not be eligible to vote if the debt securities have
been fully defeased as described below under "Defeasance -- Full Defeasance."

      STREET NAME AND OTHER INDIRECT HOLDERS SHOULD CONSULT THEIR BANKS, BROKERS
OR OTHER FINANCIAL INSTITUTIONS FOR INFORMATION ON HOW APPROVAL MAY BE GRANTED
OR DENIED IF SOUTHWEST SEEKS TO CHANGE THE INDENTURE OR THE DEBT SECURITIES OR
REQUEST A WAIVER.


                                       8

ABSENCE OF RESTRICTIVE COVENANTS

      The indenture does not contain any promises by Southwest on how it will
operate its business, and does not restrict Southwest's ability to incur debt or
grant liens on its assets. If Southwest determines to include such a promise for
the benefit of a particular series of debt securities, such promise, or
restrictive covenant, will be described in the prospectus supplement relating to
that series of debt securities.

DEFEASANCE

      Southwest may be completely released from its payment and other
obligations on the debt securities. The following discussion of defeasance will
be applicable to your series of debt securities only if Southwest chooses to
have them apply to that series. If Southwest does so choose, it will state that
in the prospectus supplement. If Southwest obtains a ruling from the Internal
Revenue Service or there is a change in federal tax law, as described below,
Southwest can legally release itself from any payment or other obligations on
the debt securities, called full or legal defeasance, if Southwest puts in place
the following other arrangements for you to be repaid:

      -     Southwest must deposit in trust for your benefit and the benefit of
all direct holders of the debt securities a combination of money and U.S.
government or U.S. government agency notes or bonds that will generate enough
cash to make interest, principal and any other payments on the debt securities
on their various due dates.

      -     There must be a change in federal tax law or a ruling from the
Internal Revenue Service that lets Southwest make the above deposit without
causing you to be taxed on the debt securities any differently than if Southwest
did not make the deposit and just repaid the debt securities. Under current
federal tax law, the deposit and Southwest's legal release from the debt
securities would be treated as though we took back your debt securities and gave
you your share of the cash and notes or bonds deposited in trust. In that event,
you could recognize gain or loss on the debt securities you give back to
Southwest.

      -     Southwest must deliver to the trustee a legal opinion of Southwest's
counsel confirming, among other things, the tax law change described above.

      If we are able to fully defease the debt securities, as described above,
you would have to rely solely on the trust deposit for repayment on the debt
securities. You could not look to Southwest for repayment.

DEFAULT AND RELATED MATTERS

      Ranking. The debt securities are not secured by any of Southwest's
property or assets. Accordingly, your ownership of debt securities means you are
one of Southwest's unsecured creditors. The debt securities are not subordinated
to any of Southwest's other debt obligations and therefore they rank equally
with all of Southwest's other unsecured and unsubordinated indebtedness.

      Events of Default. You will have special rights if an event of default
occurs and is not cured, as described later in this subsection.


                                       9

      What is an Event of Default? The term "event of default" means any of the
following:

      -     Southwest does not pay the principal or any premium on a debt
security when due.

      -     Southwest does not pay interest on a debt security within 30 days of
its due date.

      -     Southwest remains in breach of any other covenant or agreement in
the indenture for 90 days after it receives a notice of default stating it is in
breach. The notice must be sent by either the trustee or holders of 25% of the
outstanding principal amount of debt securities of the affected series.

      -     Southwest defaults on any indebtedness for borrowed money totaling
over $50,000,000 and Southwest's obligation to repay such indebtedness is
accelerated, and this repayment obligation remains accelerated for 10 days after
Southwest receives a notice of default by the trustee or holders of 25% of the
outstanding principal amount of the affected debt securities.

      -     Southwest files for bankruptcy or certain other events in
bankruptcy, insolvency or reorganization occur.

      Remedies if an Event of Default Occurs. If an event of default has
occurred and has not been cured, the trustee or the holders of at least 25% in
principal amount of the debt securities of the affected series may declare the
entire principal amount (or, in the case of original issue discount securities,
the portion of the principal amount that is specified in the terms of the
affected debt security) of all the debt securities of that series, plus accrued
interest, to be due and immediately payable. This is called a declaration of
acceleration of maturity. However, a declaration of acceleration of maturity may
be cancelled, but only before a judgment or decree based on the acceleration has
been obtained, by the holders of at least a majority in principal amount of the
debt securities of the affected series.

      Reference is made to the prospectus supplement relating to any series of
debt securities which are original issue discount securities for the particular
provisions relating to acceleration of the maturity of a portion of the
principal amount of original issue discount securities upon the occurrence of an
event of default and its continuation.

      Except in cases of default, where the trustee has some special duties, the
trustee is not required to take any action under the indenture at the request of
any holders unless the holders offer the trustee reasonable protection from
expenses and liability, called an indemnity. If reasonable indemnity is
provided, the holders of a majority of the outstanding principal amount of the
securities of the relevant series may direct the time, method and place of
conducting any lawsuit or other formal legal action seeking any remedy available
to the trustee. These majority holders may also direct the trustee in performing
any other action under the indenture.

      Before you bypass the trustee and bring your own lawsuit or other formal
legal action or take other steps to enforce your rights or protect your
interests relating to the debt securities, the following must occur:


                                       10

      -     You must give the trustee written notice that an event of default
has occurred and remains uncured.

      -     The holders of at least 25% of the outstanding principal amount of
all the securities of the relevant series must make a written request that the
trustee take action because of an event of default, and must offer reasonable
indemnity to the trustee against the cost and other liabilities of taking that
action.

      -     The trustee must have not taken action for 60 days after receipt of
the above written request and offer of indemnity and no directions inconsistent
with the above written request must have been given to the trustee during such
period.

      However, you are entitled at any time to bring a lawsuit for the payment
of money due on your debt security on or after its due date.

      STREET NAME AND OTHER INDIRECT HOLDERS SHOULD CONSULT THEIR BANKS, BROKERS
OR OTHER FINANCIAL INSTITUTIONS FOR INFORMATION ON HOW TO GIVE NOTICE OR
DIRECTION TO OR MAKE A REQUEST OF THE TRUSTEE AND TO MAKE OR CANCEL A
DECLARATION OF ACCELERATION.

      Southwest will furnish to the trustee every year a written statement of
certain of its officers certifying that to their knowledge Southwest is in
compliance with the indenture and the debt securities, or else specifying any
default and indicating the nature and status of the default.

CONCERNING THE TRUSTEE

      The trustee under the indenture is U.S. Trust Company of Texas, N.A.

      The indenture contains certain limitations on the right of the trustee,
should it become a creditor of Southwest, to obtain payment of claims in certain
cases, or to realize for its own account on certain property received in respect
of any such claim as security or otherwise. The trustee will be permitted to
engage in certain other transactions; however, if it acquires any conflicting
interest (as described in the indenture) it must eliminate such conflict or
resign.

                              PLAN OF DISTRIBUTION

      Southwest may sell debt securities:

      -     to or through underwriting syndicates represented by managing
underwriters;

      -     through one or more underwriters without a syndicate for them to
offer and sell to the public;

      -     through dealers or agents; and

      -     to investors directly in negotiated sales or in competitively bid
transactions.


                                       11

      Any underwriter or agent involved in the offer and sale of any series of
the debt securities will be named in the prospectus supplement.

      The prospectus supplement for each series of debt securities will
describe:

      -     the terms of the offering of those debt securities, including the
name of the agent or the name or names of any underwriters;

      -     the public offering or purchase price;

      -     any discounts and commissions to be allowed or paid to the agent or
underwriters and all other items constituting underwriting compensation;

      -     any discounts and commissions to be allowed or paid to dealers; and

      -     other specific terms of the particular debt securities.

      Only the agents or underwriters named in a prospectus supplement are
agents or underwriters in connection with the debt securities being offered by
that prospectus supplement.

      Underwriters, agents and dealers may be entitled, under agreements with
Southwest, to indemnification against certain civil liabilities, including
liabilities under the Securities Act of 1933.

      Underwriters to whom debt securities are sold by Southwest for public
offering and sale are obliged to purchase all of those particular debt
securities if any are purchased. This obligation is subject to certain
conditions and may be modified in the applicable prospectus supplement.

      Each series of debt securities will be a new issue of securities and will
not have an established trading market. Unless otherwise indicated in the
applicable prospectus supplement, Southwest will not list any series of debt
securities on an exchange. No assurance can be given that you will be able to
resell any debt securities that you may purchase.

      Underwriters, dealers or agents may engage in transactions with, or
perform services for, Southwest or its affiliates in the ordinary course of
business.

                         VALIDITY OF THE DEBT SECURITIES

      Unless otherwise indicated in the applicable prospectus supplement, the
validity of the debt securities offered hereby will be passed upon for us by
Deborah Ackerman, Vice President -- General Counsel.

                                     EXPERTS

      Ernst & Young, LLP, independent auditors, have audited our consolidated
financial statements included in our Annual Report on Form 10-K for the year
ended December 31, 2000, as set forth in their report, which is incorporated by
reference in this prospectus and elsewhere in the registration statement. Our
consolidated financial statements are incorporated by reference in reliance on
Ernst & Young LLP's report, given on their authority as experts in accounting
and auditing.


                                       12

                       WHERE YOU CAN FIND MORE INFORMATION

      We file annual, quarterly and special reports, proxy statements and other
information with the Securities and Exchange Commission. You may read and copy
any documents we file at the SEC's public reference room, 450 Fifth Street,
N.W., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further
information on the public reference room. Our SEC filings are also available to
the public on the SEC's web site at http://www.sec.gov and through the New York
Stock Exchange, 20 Broad Street, New York, New York 10005, on which our common
stock is listed.

      The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be part of this prospectus, and later information that we file
with the SEC will automatically update and supersede this information as well as
the information included in this prospectus. We incorporate by reference the
documents listed below and any future filings made with the SEC under Sections
13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934 until we sell
all the debt securities.

      -     Annual Report on Form 10-K for the fiscal year ended December 31,
2000;

      -     Quarterly Reports on Form 10-Q for the quarters ended March 31 and
June 30, 2001; and

      -     Current Report on Form 8-K dated October 3, 2001.

      Any party to whom this prospectus is delivered, including a holder in
street name, may request a copy of these filings (other than any exhibits unless
specifically incorporated by reference into this prospectus), at no cost, by
writing or telephoning us at the following address:

                              Southwest Airlines Co.
                              Investor Relations
                              P.O. Box 36611, HDQ-6FC
                              2702 Love Field Drive
                              Dallas, Texas 75235
                              (214) 792-4000


                                       13

                 SUBJECT TO COMPLETION, DATED October 11, 2001

                                   PROSPECTUS

                             SOUTHWEST AIRLINES CO.

                            PASS THROUGH CERTIFICATES
                                 _____________

      This prospectus relates to the issuance of Pass Through Certificates by
one or more Pass Through Trusts to be formed by Southwest Airlines Co.

                                THE CERTIFICATES:

      -     Will be issued in one or more series with distribution rates and
distribution dates specified in the prospectus supplement;

      -     Will represent interests in the relevant Pass Through Trust only and
will be repaid only from the assets of that Trust, and will not represent
obligations of, or be guaranteed by, Southwest;

      -     May have one or more forms of liquidity enhancement; and

      -     Will be issued in registered form and may be issued in accordance
with a book-entry system.

      The aggregate public offering price of the Certificates will not exceed
$1,000,000,000.

                            EACH PASS THROUGH TRUST:

      -     Will issue one or more series of Certificates;

      -     Will use the proceeds of each series of Certificates to purchase
Equipment Notes of one or more series, each with an interest rate equal to the
rate on the related series of Certificates and with a maturity date on or prior
to the final distribution date for the related series of Certificates; and

      -     Will pass through principal and interest paid on the Equipment Notes
that it owns, subject to any applicable subordination provisions.

                              THE EQUIPMENT NOTES:

      -     Will be issued in series;

      -     Will be issued either in connection with sale/leaseback transactions
relating to aircraft leased to us, or to finance or refinance all or a portion
of the cost of aircraft owned by us or to raise funds for general corporate
purposes;

      -     If issued in connection with leased aircraft, will not be our
obligations and will not be guaranteed by us, but amounts due from us under the
relevant lease will be sufficient to make all payments required under those
Equipment Notes; and

      -     Will be secured by the aircraft specified in the prospectus
supplement and, in the case of any leased aircraft, by the interest of lessor
in that lease.

      This prospectus is accompanied by a prospectus supplement which includes
additional information as to the particular series of Certificates being sold
and the underlying Equipment Notes. Sales of Certificates may not be consummated
without both this prospectus and a prospectus supplement.

      NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED THAT
THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

      THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE
MAY NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER
TO SELL SECURITIES AND IT IS NOT SOLICITING AN OFFER TO BUY SECURITIES IN ANY
STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.

               The date of this prospectus is October _____, 2001



                                TABLE OF CONTENTS

                                                                            PAGE
                                   PROSPECTUS
                                                                         
About This Prospectus....................................................      i
Southwest Airlines Co. ..................................................      1
Summary..................................................................      1
Use of Proceeds..........................................................      4
Ratios of Earnings to Fixed Charges......................................      4
Description of the Certificates..........................................      5
Description of the Equipment Notes.......................................     22
Certain United States Federal Income Tax Consequences....................     28
ERISA Considerations.....................................................     31
Plan of Distribution.....................................................     32
Validity of the Certificates.............................................     33
Experts..................................................................     34
Where You Can Find More Information......................................     34


      You should rely only on the information contained in this prospectus or
any prospectus supplement or information contained in documents which you are
referred to in this prospectus or any prospectus supplement. Southwest has not
authorized anyone to provide you with information different from that contained
in this prospectus or any prospectus supplement. Southwest is offering to sell
the pass through certificates only in jurisdictions where offers and sales are
permitted. The information contained in this prospectus or any prospectus
supplement is accurate only as of the date on the front of those documents,
regardless of the time of delivery of the documents or any sale of the pass
through certificates.

                              ABOUT THIS PROSPECTUS

      This prospectus is part of a registration statement that Southwest filed
with the Securities and Exchange Commission utilizing a shelf registration
process. Under this shelf process, the Certificates described in this prospectus
may be sold in one or more offerings up to a total offering amount of
$1,000,000,000. This prospectus provides you with a general description of the
Certificates that may be offered.

      Each time Certificates are sold, Southwest will provide a prospectus
supplement that will contain specific information about the terms of that
offering. The prospectus supplement may also add, update or change information
contained in this prospectus. You should read both this prospectus and any
prospectus supplement together with additional information described in the
section entitled "Where You Can Find More Information."

      For more detail, you should read our registration statement and the
exhibits filed with our registration statement.


                                      (i)

      In this prospectus, references to "Southwest," "we," "us" and "our" mean
Southwest Airlines Co.


                                      (ii)

                             SOUTHWEST AIRLINES CO.

      Southwest Airlines Co. is a major domestic airline which provides single
class air transportation characterized by frequent, high quality service at
affordable prices. Our service primarily appeals to the business commuter as
well as the leisure traveler. Southwest Airlines began serving Customers in 1971
with three Boeing 737 aircraft serving three cities. As of September 30, 2001,
Southwest operated 358 Boeing 737 aircraft and provided service to 58 airports
in 57 cities in 29 states throughout the United States. Please refer to the
Section "Where You Can Find More Information" to learn more about Southwest
Airlines.

      Our principal executive offices are located at 2702 Love Field Drive, P.O.
Box 36611, Dallas, Texas 75235, and our telephone number is (214) 792-4000.
Southwest is incorporated under the laws of the State of Texas.

                                     SUMMARY

CERTIFICATES

      Pass through certificates are securities that evidence an ownership
interest in a pass through trust. The holders of the certificates issued by a
pass through trust will be the beneficiaries of that trust. For convenience, we
may refer to pass through certificates as "certificates" and refer to the holder
of a pass through certificate as a "certificateholder."

      The beneficial interest in a pass through trust represented by a
certificate will be a percentage interest in the property of that trust equal to
the original face amount of such certificate divided by the original face amount
of all of the certificates issued by that trust. Each certificate will represent
a beneficial interest only in the property of the pass through trust that issued
the certificate. Multiple series of certificates may be issued. If more than one
series of certificates is issued, each series of certificates will be issued by
a separate pass through trust.

      The property that will be held by each pass through trust will include
equipment notes secured by aircraft that we own or lease. Payments of principal
and interest on the equipment notes owned by a pass through trust will be passed
through to holders of certificates issued by that trust in accordance with the
terms of the pass through trust agreement pursuant to which the trust was
formed.

      If certificates of any series are entitled to the benefits of a liquidity
facility or other form of credit enhancement, the prospectus supplement relating
to that series will describe the terms of the liquidity facility or other form
of credit enhancement. A liquidity facility is a revolving credit agreement,
letter of credit, bank guarantee, insurance policy or other instrument or
agreement under which another person agrees to make certain payments in respect
of the certificates if there is a shortfall in amounts otherwise available for
distribution. While a liquidity facility is designed to increase the likelihood
of the timely payment of certain amounts due under certificates, it is not a
guarantee of timely or ultimate payment.

      The rights of a pass through trustee to receive monies payable under
equipment notes held for that pass through trustee may be subject to the effect
of subordination provisions contained in an intercreditor agreement described in
the prospectus supplement for a series of certificates. An


                                       1

intercreditor agreement will set forth the terms and conditions upon which
payments made under the equipment notes and payments made under any liquidity
facility will be received, shared and distributed among the several pass through
trustees and the liquidity provider.

      We may offer and sell up to $1,000,000,000 of aggregate initial offering
price of certificates pursuant to this prospectus and related prospectus
supplements in one or more offerings of certificates.

PASS THROUGH TRUSTS

      We will form a separate pass through trust to issue each series of
certificates. Each pass through trust will be formed by us, as creator of each
pass through trust, and a national or state bank or trust company, as trustee.

      Unless otherwise stated in a prospectus supplement, Wilmington Trust
Company will be the trustee of each pass through trust. For convenience, we may
refer to the pass through trustee as the trustee.

      Each pass through trust will be governed by a trust instrument that
creates the trust and sets forth the powers of the trustee and the rights of the
beneficiaries. The beneficiaries of a pass through trust will be the holders of
certificates issued by that trust. The trust instrument for each pass through
trust will consist of a basic pass through trust agreement between us and the
pass through trustee, which we refer to as the "Basic Agreement," and a
supplement to that basic agreement, which we refer to as a "pass through trust
supplement."

      When a pass through trust supplement is signed and delivered, the pass
through trustee, on behalf of the related pass through trust, will enter into
one or more purchase or refunding agreements, typically referred to as "note
purchase agreements" or "participation agreements" under which it will agree to
purchase one or more promissory notes secured by aircraft described in the
applicable prospectus supplement. These secured promissory notes are referred to
as "equipment notes."

      Under the applicable note purchase agreement or participation agreement,
the pass through trustee, on behalf of the related pass through trust, will
purchase one or more equipment notes. The equipment notes that are the property
of a pass through trust will have:

      -     identical interest rates, in each case equal to the rate applicable
to the certificates issued by such pass through trust; and

      -     identical priority of payment relative to each of the other
equipment notes held for such pass through trust.

      If any portion of the proceeds of an offering of a series of certificates
is not used to purchase equipment notes on the date the certificates are
originally issued, those proceeds will be held for the benefit of the
certificateholders. If any of the proceeds are not later used to purchase
equipment notes by the date specified in the applicable prospectus supplement,
the proceeds will be returned to the certificateholders.


                                       2

EQUIPMENT NOTES

      The equipment notes owned by a pass through trust may consist of any
combination of:

      -     Equipment notes issued by an owner trustee and secured by an
aircraft owned by that trustee and leased to us. We refer to these equipment
notes as "leased aircraft notes."

      -     Equipment notes issued by us and secured by an aircraft owned by us.
We refer to these equipment notes as "owned aircraft notes."

      Leased Aircraft Notes. Except as specified in a prospectus supplement,
leased aircraft notes will be issued by a bank, trust company, financial
institution or other entity solely in its capacity as owner trustee in a
leveraged lease transaction. In a leveraged lease transaction, one or more
persons will form an owner trust to acquire an aircraft and then that owner
trust will lease the aircraft to us. The investors that are the beneficiaries of
the owner trusts are typically referred to as owner participants. Each owner
participant will contribute a portion of the purchase price of the aircraft to
the owner trust, and the remainder of the purchase price of the aircraft will be
financed, or "leveraged," through the issuance of leased aircraft notes. Leased
aircraft notes may also be issued to refinance an aircraft previously financed
in a leveraged lease transaction or otherwise.

      The leased aircraft notes will be issued pursuant to a separate indenture
between the owner trustee and a bank, trust company, financial institution or
other entity, as loan trustee. The indenture entered into in connection with the
issuance of leased aircraft notes will be referred to as a "leased aircraft
indenture." The loan trustee under a leased aircraft indenture will act as a
trustee for the holders of the leased aircraft notes issued under that leased
aircraft indenture.

      In a leveraged lease transaction, we will pay or advance rent and other
amounts to the owner trustee in its capacity as lessor under the lease. The
owner trustee will use the rent payments and certain other amounts received by
it to make payments of principal and interest on the leased aircraft notes. The
owner trustee also will assign its rights to receive basic rent and certain
other payments to a loan trustee as security for the owner trustee's obligations
to pay principal of, premium, if any, and interest on the leased aircraft notes.

      Payments or advances required to be made under a lease and related
agreements will at all times be sufficient to make scheduled payments of
principal of, and interest on, the leased aircraft notes issued to finance the
aircraft subject to that lease. However, we will not have any direct obligation
to pay principal of, or interest on, the leased aircraft notes. No owner
participant or owner trustee will be personally liable for any amount payable
under a leased aircraft indenture or the leased aircraft notes issued under that
indenture.

      Owned Aircraft Notes. We may finance or refinance aircraft that we own
through the issuance of owned aircraft notes. Owned aircraft notes relating to
an owned aircraft will be issued under a separate indenture relating to that
owned aircraft. Each separate indenture relating to owned aircraft notes will be
between us and a bank, trust company, financial institution or other entity, as
loan trustee. The indenture entered into in connection with the issuance of
owned aircraft notes will be referred to as an "owned aircraft indenture."
Because we often refer to owned aircraft indentures and leased aircraft
indentures together, we sometimes refer to them collectively as the


                                       3

"indentures." The loan trustee under an owned aircraft indenture will act as a
trustee for the holders of the owned aircraft notes issued under that owned
aircraft indenture.

      Unlike the leased aircraft notes, we will have a direct obligation to pay
the principal of, and interest on, the owned aircraft notes.

                                 USE OF PROCEEDS

      The trustee will use the proceeds of the certificates for the purchase of
one or more equipment notes. Except as set forth in a prospectus supplement for
a specific offering of certificates, the equipment notes will be issued:

      -     To finance the purchase of aircraft by us, or to refinance any debt
previously issued by us in connection with our purchase of aircraft;

      -     To finance or refinance the debt portion and, in certain cases, to
refinance some of the equity portion of one or more separate leveraged lease
transactions entered into by us, as lessee of aircraft; and

      -     To provide us with funds for general corporate purposes.

      General corporate purposes of Southwest may include, among other possible
uses, the repayment of short-term or long-term indebtedness and capital
expenditures.

      To the extent that the proceeds of any offering of certificates are not
used to purchase equipment notes on the date of issuance of those certificates,
the relevant proceeds will be held for the benefit of those certificateholders.
If those proceeds are not used to purchase equipment notes by the date specified
in the applicable prospectus supplement, they will be returned to the applicable
certificateholders. See "Description of Certificates -- Delayed Purchase of
Equipment Notes" for a description of the procedure for delayed purchase of
equipment notes.

      The prospectus supplement with respect to any offering of certificates
will provide additional details with respect to the use of proceeds of those
certificates, and with respect to the use of proceeds of any equipment notes to
be purchased by the Trust.

                       RATIOS OF EARNINGS TO FIXED CHARGES

      The following table sets forth the historical ratios of earnings to fixed
charges of Southwest for the periods indicated:



SIX MONTHS ENDED
     JUNE 30,                          YEAR ENDED DECEMBER 31,
----------------        ----------------------------------------------------
                                                      
2000        2001        1996        1997        1998        1999        2000
5.56        5.77        2.73        3.50        4.58        5.01        5.97


      Earnings represent:

      -     Income before income taxes, excluding the cumulative effect of
accounting changes; plus

      -     Fixed charges, excluding capitalized interest.


                                       4

      Fixed charges include:

      -     Interest, whether expensed or capitalized; and

      -     A portion of rental expense. Management of Southwest believes this
is representative of the interest factor in those periods.

                         DESCRIPTION OF THE CERTIFICATES

      The following description is a summary of the terms of the certificates
that we expect will be common to all series of certificates. We will describe
the financial terms and other specific terms of any series of certificates in a
prospectus supplement. To the extent that any provision in any prospectus
supplement is inconsistent with any provision in this prospectus, the provision
of the prospectus supplement will control.

      Because the following description is a summary, it does not describe every
aspect of the certificates, and it is subject to and qualified in its entirety
by reference to all the provisions of the pass through trust agreement and the
applicable supplements to the pass through trust agreement. For convenience, we
will refer to the pass through trust agreement between the pass through trustee
and us as the "Basic Agreement," and to the Basic Agreement as supplemented by a
supplement as a "pass through trust agreement." The form of Basic Agreement has
been filed as an exhibit to the registration statement of which this prospectus
is a part. The supplement to the Basic Agreement relating to each series of
certificates and the forms of the other agreements described in this prospectus
and the applicable prospectus supplement will be filed as exhibits to a
post-effective amendment to the registration statement of which this prospectus
is a part, a Current Report on Form 8-K, a Quarterly Report on Form 10-Q or an
Annual Report on Form 10-K, as applicable, filed by us with the SEC.

GENERAL

      Except as amended by a supplement to the Basic Agreement, the terms of the
Basic Agreement generally will apply to all of the pass through trusts that we
form to issue certificates. We will create a separate pass through trust for
each series of certificates by entering into a separate supplement to the Basic
Agreement. Each supplement to the Basic Agreement will contain the additional
terms governing the specific pass through trust to which it relates and, to the
extent inconsistent with the Basic Agreement, will supersede the Basic
Agreement.

      Certificates for a pass through trust will be issued pursuant to the pass
through trust agreement applicable to such pass through trust. Unless otherwise
stated in the applicable prospectus supplement, each pass through certificate
will be issued in a minimum denomination of $1,000 or a multiple of $1,000,
except that one certificate of each series may be issued in a different
denomination.

      Each certificate will represent a fractional undivided interest in the
property of the pass through trust that issued the certificate. All payments and
distributions made with respect to a certificate will be made only from the
property owned by the pass through trust that issued the certificate. The
certificates do not represent an interest in or obligation of Southwest, the
pass through trustee, any of the owner trustees or loan trustees, in their
individual capacities, or any


                                       5

owner participant. Each certificateholder by its acceptance of a certificate
agrees to look solely to the income and proceeds from the property of the
applicable pass through trust as provided in the pass through trust agreement.

      The property of each pass through trust for which a series of certificates
will be issued will include:

      -     the equipment notes held for the pass through trust;

      -     all monies at any time paid under the equipment notes held for the
pass through trust;

      -     the rights of such pass through trust to acquire equipment notes;

      -     funds from time to time deposited with the pass through trustee in
accounts relating to that pass through trust; and

      -     if so specified in the relevant prospectus supplement, rights under
intercreditor agreements relating to cross-subordination arrangements and monies
receivable under a liquidity facility.

      The rights of a pass through trustee to receive monies payable under
equipment notes held for that pass through trustee may be subject to the effect
of subordination provisions contained in an intercreditor agreement described in
the prospectus supplement for a series of certificates. An intercreditor
agreement refers to an agreement among the pass through trustees and, if
applicable, a liquidity provider under a liquidity facility, as creditors of the
issuers of the equipment notes owned by the pass through trustees. An
intercreditor agreement will set forth the terms and conditions upon which
payments made under the equipment notes and payments made under any liquidity
facility will be received, shared and distributed among the several pass through
trustees and the liquidity provider. In addition, the intercreditor agreement
will set forth agreements among the pass through trustees and the liquidity
provider relating to the exercise of remedies under the equipment notes and the
indentures.

      Cross-subordination refers to an agreement under which payments on a
junior class of equipment notes issued under an indenture are distributed to a
pass through trustee that holds a senior class of equipment notes issued under a
different indenture on which all required payments were not made. The effect of
this distribution mechanism is that holders of certificates of a pass through
trust that owns a junior class of equipment notes will not receive payments made
on that junior class of equipment notes until certain distributions are made on
the certificates of the pass through trust that owns a senior class of equipment
notes.

      Equipment notes owned by a pass through trust may be leased aircraft
notes, owned aircraft notes or a combination of leased aircraft notes and owned
aircraft notes.

      Leased aircraft notes will be issued in connection with the leveraged
lease of an aircraft to us. Except as set forth in the applicable prospectus
supplement, each leased aircraft will be leased to us under a lease between us,
as lessee, and an owner trustee, as lessor. Each owner trustee will


                                       6

issue leased aircraft notes on a non-recourse basis under a separate leased
aircraft indenture between it and the applicable loan trustee. The owner trustee
will use the proceeds of the sale of the leased aircraft notes to finance or
refinance a portion of the purchase price paid or to be paid by the owner
trustee for the applicable leased aircraft. The owner trustee will obtain the
remainder of the funding for the leased aircraft from an equity contribution
from the owner participant that is the beneficiary of the owner trust and, to
the extent set forth in the applicable prospectus supplement, additional debt
secured by the applicable leased aircraft or other sources. A leased aircraft
also may be subject to other financing arrangements.

      Generally, neither the owner trustee nor the owner participant will be
personally liable for any principal or interest payable under any leased
aircraft indenture or any leased aircraft notes. In some cases, an owner
participant may be required to make payments to an owner trustee that are to be
used by the owner trustee to pay principal of, and interest on, the equipment
notes. If an owner participant is required to make payments to be used by an
owner trustee to pay principal of, and interest on, the equipment notes and the
owner participant fails to make the payment, we will be required to provide the
owner trustee with funds sufficient to make the payment. We will be obligated to
make payments or advances under a lease and the related documents sufficient to
pay when due all scheduled principal and interest payments on the leased
aircraft notes issued to finance the aircraft subject to that lease.

      We will issue owned aircraft notes under separate owned aircraft
indentures. Owned aircraft notes will be issued in connection with the financing
or refinancing of an aircraft that we own. Owned aircraft notes will be
obligations that have recourse to us and the related aircraft. Any owned
aircraft may secure additional debt or be subject to other financing
arrangements.

      An indenture may provide for the issuance of multiple classes of equipment
notes. If an indenture provides for multiple classes of equipment notes, it may
also provide for differing priority of payments among the different classes.
Equipment notes issued under an indenture may be held in more than one pass
through trust, and one pass through trust may hold equipment notes issued under
more than one indenture. Unless otherwise provided in a prospectus supplement,
only equipment notes having the same priority of payment may be held for the
same pass through trust.

      Except as set forth in the prospectus supplement for any series of
certificates, interest payments on the equipment notes held for a pass through
trust will be passed through to the registered holders of certificates of that
pass through trust at the annual rate shown on the cover page of the prospectus
supplement for the certificates issued by that pass through trust. The
certificateholders' right to receive payments made in respect of the equipment
notes is subject to the effect of any cross-subordination provisions described
in the prospectus supplement for a series of certificates.

      We refer you to the prospectus supplement that accompanies this prospectus
for a description of the specific series of certificates being offered by this
prospectus and the applicable prospectus supplement, including:

      -     the specific designation, title and amount of the certificates;

      -     amounts payable on and distribution dates for the certificates;


                                       7

      -     the specific form of the certificates, including whether or not the
certificates are to be issued in accordance with a book-entry system;

      -     a description of the equipment notes to be purchased by the pass
through trust issuing that series of certificates, including:

            -     the period or periods within which, the price or prices at
      which, and the terms and conditions upon which the equipment notes may or
      must be redeemed or defeased in whole or in part, by us or an owner
      trustee;

            -     the payment priority of the equipment notes in relation to any
      other equipment notes issued with respect to the related aircraft; and

            -     any intercreditor or other rights or limitations between or
      among the holders of equipment notes of different priorities issued with
      respect to the same aircraft;

      -     a description of the aircraft to be financed with the proceeds of
the issuance of the equipment notes;

      -     a description of the note purchase agreement or participation
agreement setting forth the terms and conditions upon which that pass through
trust will purchase equipment notes;

      -     a description of the indentures under which the equipment notes to
be purchased for that pass through trust will be issued;

      -     a description of the events of default, the remedies exercisable
upon the occurrence of events of default and any limitations on the exercise of
those remedies under the indentures pursuant to which the equipment notes to be
purchased for that pass through trust will be issued;

      -     if the certificates relate to leased aircraft, a description of the
leases to be entered into by the owner trustees and us;

      -     if the certificates relate to leased aircraft, a description of the
provisions of the leased aircraft indentures governing:

            -     the rights of the related owner trustee and/or owner
      participant to cure our failure to pay rent under the leases; and

            -     any limitations on the exercise of remedies with respect to
      the leased aircraft notes;

      -     if the certificates relate to leased aircraft, a description of the
participation agreements that will set forth the terms and conditions upon which
the owner participant, the owner trustee, the pass through trustees, the loan
trustee and we agree to enter into a leveraged lease transaction;


                                       8

      -     if the certificates relate to an owned aircraft, a description of
the participation agreements that will set forth the terms and conditions upon
which the applicable pass through trustees, the loan trustee and we agree to
enter into a financing transaction for the owned aircraft;

      -     a description of the limitations, if any, on amendments to leases,
indentures, pass through trust agreements, participation agreements and other
material agreements entered into in connection with the issuance of equipment
notes;

      -     a description of any cross-default provisions in the indentures;

      -     a description of any cross-collateralization provisions in the
indentures;

      -     a description of any agreement among the holders of equipment notes
and any liquidity provider governing the receipt and distribution of monies with
respect to the equipment notes and the enforcement of remedies under the
indentures, including a description of any applicable intercreditor and
cross-subordination arrangements;

      -     a description of any liquidity facility or other credit enhancement
relating to the certificates;

      -     if the certificates relate to aircraft that have not yet been
delivered or financed, a description of any deposit or escrow agreement or other
arrangement providing for the deposit and investment of funds pending the
purchase of equipment notes and the financing of an owned aircraft or leased
aircraft; and

      -     any other special terms pertaining to the certificates.

      The concept of cross-default mentioned above refers to a situation where a
default under one indenture or lease results in a default under other indentures
or leases. We currently do not expect any indentures or leases to contain
cross-default provisions. The concept of cross-collateralization mentioned above
refers to the situation where collateral that secures obligations incurred under
one indenture also serves as collateral for obligations under one or more other
indentures. We currently do not expect any indentures to be
cross-collateralized.

BOOK-ENTRY REGISTRATION

      General. If specified in the applicable prospectus supplement, the
certificates will be subject to the procedures and provisions described below.

      Upon issuance, each series of certificates will be represented by one or
more fully registered global certificates. Each global certificate will be
deposited with, or on behalf of, The Depository Trust Company, referred to as
DTC, and registered in the name of Cede & Co., the nominee of DTC. No purchaser
of a certificate will be entitled to receive a physical certificate representing
an interest in the global certificates, except as set forth below under "--
Physical Certificates." For convenience, we refer to such purchasers as
"certificate owners." Unless and until physical certificates are issued under
the limited circumstances described below, all references in this prospectus and
any prospectus supplement to actions by certificateholders will refer to actions


                                       9

taken by DTC upon instructions from DTC participants, and all references to
distributions, notices, reports and statements to certificateholders will refer,
as the case may be, to distributions, notices, reports and statements to DTC or
Cede, as the registered holder of the certificates, or to DTC participants for
distribution to certificateholders in accordance with DTC procedures.

      DTC is a limited purpose trust company organized under the laws of the
State of New York, a member of the Federal Reserve System, a "clearing
corporation" within the meaning of the New York Uniform Commercial Code and
"clearing agency" registered pursuant to Section 17A of the Securities Exchange
Act of 1934.

      Under the New York Uniform Commercial Code, a "clearing corporation" is
defined as:

      -     a person that is registered as a "clearing agency" under the federal
securities laws;

      -     a federal reserve bank; or

      -     any other person that provides clearance or settlement services with
respect to financial assets that would require it to register as a clearing
agency under the federal securities laws but for an exclusion or exemption from
the registration requirement, if its activities as a clearing corporation,
including promulgation of rules, are subject to regulation by a federal or state
governmental authority.

      A "clearing agency" is an organization established for the execution of
trades by transferring funds, assigning deliveries and guaranteeing the
performance of the obligations of parties to trades.

      DTC was created to hold securities for its participants and to facilitate
the clearance and settlement of securities transactions between DTC participants
through electronic book-entry changes in the accounts of DTC participants. The
ability to execute transactions through book-entry changes in accounts
eliminates the need for transfer of physical certificates. DTC is owned by a
number of DTC participants and by the New York Stock Exchange, the American
Stock Exchange, and the National Association of Securities Dealers. DTC
participants include securities brokers and dealers, banks, trust companies,
clearing corporations and certain other organizations. Banks, brokers, dealers,
trust companies and other entities that clear through or maintain a custodial
relationship with a DTC participant, either directly or indirectly, are indirect
participants in the DTC system.

      Under the rules, regulations and procedures creating and affecting DTC and
its operations, DTC is required to make book-entry transfers of the certificates
among DTC participants on whose behalf it acts with respect to the certificates
and to receive and transmit distributions of principal, premium, if any, and
interest with respect to the certificates. DTC participants and indirect DTC
participants with which certificate owners have accounts similarly are required
to make book-entry transfers and receive and transmit the payments on behalf of
their respective customers. Certificate owners that are not DTC participants or
indirect DTC participants but desire to purchase, sell or otherwise transfer
ownership of, or other interests in, the certificates may do so only through DTC
participants and indirect DTC participants. In addition, certificate owners will
receive all


                                       10

distributions of principal, premium, if any, and interest from the pass through
trustee through DTC participants or indirect DTC participants, as the case may
be.

      Under a book-entry format, certificate owners may experience some delay in
their receipt of payments, because payments with respect to the certificates
will be forwarded by the pass through trustee to Cede, as nominee for DTC. DTC
will forward payments in same-day funds to each DTC participant who is credited
with ownership of the certificates in an amount proportionate to the principal
amount of that DTC participant's holdings of beneficial interests in the
certificates, as shown on the records of DTC or its nominee. Each such DTC
participant will forward payments to its indirect DTC participants in accordance
with standing instructions and customary industry practices. DTC participants
and indirect DTC participants will be responsible for forwarding distributions
to certificate owners for whom they act. Accordingly, although certificate
owners will not possess physical certificates, DTC's rules provide a mechanism
by which certificate owners will receive payments on the certificates and will
be able to transfer their interests.

      Unless and until physical certificates are issued under the limited
circumstances described below, the only physical certificateholder will be Cede,
as nominee of DTC. Certificate owners will not be recognized by the pass through
trustee as registered owners of certificates under the pass through trust
agreement. Certificate owners will be permitted to exercise their rights under
the pass through trust agreement only indirectly through DTC. DTC will take any
action permitted to be taken by a certificateholder under the pass through trust
agreement only at the direction of one or more DTC participants to whose
accounts with DTC the certificates are credited. In the event any action
requires approval by certificateholders of a certain percentage of the
beneficial interests in a pass through trust, DTC will take action only at the
direction of and on behalf of DTC participants whose holdings include undivided
interests that satisfy the required percentage. DTC may take conflicting actions
with respect to other undivided interests to the extent that the actions are
taken on behalf of DTC participants whose holdings include those undivided
interests. DTC will convey notices and other communications to DTC participants,
and DTC participants will convey notices and other communications to indirect
DTC participants in accordance with arrangements among them. Arrangements among
DTC and its direct and indirect participants are subject to any statutory or
regulatory requirements as may be in effect from time to time. DTC's rules
applicable to itself and DTC participants are on file with the SEC.

      A certificate owner's ability to pledge the certificates to persons or
entities that do not participate in the DTC system, or otherwise to act with
respect to the certificates, may be limited due to the lack of a physical
certificate to evidence ownership of the certificates, and because DTC can only
act on behalf of DTC participants, who in turn act on behalf of indirect DTC
participants.

      Neither we nor the pass through trustee will have any liability for any
aspect of the records relating to or payments made on account of beneficial
ownership interests in the certificates held by Cede, as nominee for DTC, for
maintaining, supervising or reviewing any records relating to the beneficial
ownership interests or for the performance by DTC, any DTC participant or any
indirect DTC participant of their respective obligations under the rules and
procedures governing their obligations.

      The applicable prospectus supplement will specify any additional
book-entry registration procedures applicable to certificates denominated in a
currency other than U.S. dollars.


                                       11

      Same-Day Settlement and Payment. As long as the certificates are
registered in the name of DTC or its nominee, we will make all payments to the
loan trustee under any lease or any owned aircraft indenture in immediately
available funds. The pass through trustee will pass through to DTC in
immediately available funds all payments received from us, including the final
distribution of principal with respect to the certificates of any pass through
trust.

      Any certificates registered in the name of DTC or its nominee will trade
in DTC's Same-Day Funds Settlement System until maturity. DTC will require
secondary market trading activity in the certificates to settle in immediately
available funds. We cannot give any assurance as to the effect, if any, of
settlement in same-day funds on trading activity in the certificates.

      Physical Certificates. Physical certificates will be issued in paper form
to certificateholders or their nominees, rather than to DTC or its nominee, only
if:

      -     we advise the pass through trustee in writing that DTC is no longer
willing or able to discharge properly its responsibilities as depository with
respect to the certificates and we are unable to locate a qualified successor;

      -     we elect to terminate the book-entry system through DTC; or

      -     after the occurrence of certain events of default or other events
specified in the related prospectus supplement, certificateholders owning at
least a majority in interest in a pass through trust advise the applicable pass
through trustee, us and DTC through DTC participants that the continuation of a
book-entry system through DTC or a successor to DTC is no longer in the
certificate owners' best interest.

      Upon the occurrence of any of the events described in the three
subparagraphs above, the applicable pass through trustee will notify all
certificate owners through DTC participants of the availability of physical
certificates. Upon surrender by DTC of the global certificates and receipt of
instructions for re-registration, the pass through trustee will reissue the
certificates as physical certificates to certificate owners.

      After physical certificates are issued, the pass through trustee or a
paying agent will make distributions of principal, premium, if any, and interest
with respect to certificates directly to holders in whose names the physical
certificates were registered at the close of business on the applicable record
date. Except for the final payment to be made with respect to a certificate, the
pass through trustee or a paying agent will make distributions by check mailed
to the addresses of the registered holders as they appear on the register
maintained by the pass through trustee. The pass through trustee or a paying
agent will make the final payment with respect to any pass through certificate
only upon presentation and surrender of the applicable pass through certificate
at the office or agency specified in the notice of final distribution to
certificateholders.

      Physical certificates will be freely transferable and exchangeable at the
office of the pass through trustee upon compliance with the requirements set
forth in the pass through trust agreement. Neither the pass through trustee nor
any transfer or exchange agent will impose a service charge for any registration
of transfer or exchange. However, the pass through trustee or


                                       12

transfer or exchange agent will require payment of a sum sufficient to cover any
tax or other governmental charge attributable to a transfer or exchange.

PAYMENTS AND DISTRIBUTIONS

      Subject to the effect of any cross-subordination provisions set forth in
the prospectus supplement for a series of certificates:

      -     Payments of principal, premium, if any, and interest with respect to
the equipment notes held for each pass through trust will be distributed by the
pass through trustee, upon receipt, to certificateholders of that trust on the
dates and in the currency specified in the applicable prospectus supplement,
except in certain cases when some or all of the equipment notes are in default
as described in the applicable prospectus supplement. Payments of principal of,
and interest on, the unpaid principal amount of the equipment notes held in each
pass through trust will be scheduled to be received by the pass through trustee
on the dates specified in the applicable prospectus supplement.

      -     Each certificateholder of a pass through trust will be entitled to
receive a pro rata share of any distribution in respect of scheduled payments of
principal and interest made on the equipment notes held for such pass through
trust.

      If we elect or are required to redeem equipment notes relating to one or
more aircraft prior to their scheduled maturity date, payments of principal,
premium (if any) and interest received by the pass through trustee as a result
of the early redemption will be distributed on a special distribution date
determined as described in the applicable prospectus supplement. Payments
received by the pass through trustee following a default under the equipment
notes held for a pass through trust will also be distributed on a special
distribution date determined in the same way. However, if following such a
default the pass through trustee receives any scheduled payments on equipment
notes on a regular distribution date or within five days thereafter, the pass
through trustee will distribute those payments on the date they are received. In
addition, if following a default under equipment notes the pass through trustee
receives payments on the equipment notes on a regular distribution date by
making a drawing under any liquidity facility, as described in the applicable
prospectus supplement, those payments will be distributed to certificateholders
on the regular distribution date. The pass through trustee will mail notice to
the certificateholders of record of the applicable pass through trust stating
the anticipated special distribution date.

POOL FACTORS

      Unless otherwise described in the applicable prospectus supplement, the
"pool balance" for each pass through trust or for the certificates issued by any
pass through trust indicates, as of any date, the portion of the original
aggregate face amount of the certificates issued by that pass through trust that
has not been distributed to certificateholders (excluding any payments of
interest or premium). The pool balance for each pass through trust as of any
distribution date will be computed after giving effect to any distribution to
certificateholders to be made on that date.

      Unless otherwise described in the applicable prospectus supplement, the
"pool factor" for a pass through trust as of any distribution date for that
trust is the quotient (rounded to the seventh


                                       13

decimal place) computed by dividing (a) the pool balance by (b) the aggregate
original face amount of the certificates issued by that pass through trust. The
pool factor for a pass through trust as of any distribution date will be
computed after giving effect to the payment of principal, if any, on the
equipment notes held for that pass through trust and distribution to
certificateholders of the payment of principal to be made on that date. Each
pass through trust will have a separate pool factor.

      The pool factor for a pass through trust initially will be 1.0000000. The
pool factor for a pass through trust will decline as described in this
prospectus and the related prospectus supplement to reflect reductions in the
pool balance of that pass through trust. As of any distribution date for a pass
through trust, a certificate will represent a share of the pool balance of that
pass through trust equal to the product obtained by multiplying the original
face amount of the certificate by the pool factor for the pass through trust
that issued such certificate. The pool factor and pool balance of each past
through trust will be mailed to the certificateholders of the pass through trust
on each distribution date.

      The pool factor for each pass through trust will decline in proportion to
the scheduled repayments of principal on the equipment notes held by that pass
through trust, unless there is an early redemption or purchase of equipment
notes held by a pass through trust or if a default occurs in the repayment of
equipment notes held by a pass through trust. In the event of a redemption,
purchase or default, the pool factor and the pool balance of each pass through
trust affected by the redemption, purchase or default will be recomputed, and a
notice will be mailed to the certificateholders of the pass through trust.

REPORTS TO CERTIFICATEHOLDERS

      The pass through trustee will include with each distribution of a payment
to certificateholders a statement setting forth the following information:

      -     the amount of the distribution allocable to principal and the amount
allocable to premium, if any;

      -     the amount of the distribution allocable to interest; and

      -     the pool balance and the pool factor for the pass through trust
after giving effect to the distribution.

      As long as the certificates are registered in the name of DTC or its
nominee, on the record date prior to each distribution date, the pass through
trustee will request from DTC a securities position listing setting forth the
names of all DTC participants reflected on DTC's books as holding interests in
the certificates on that record date. On each distribution date, the applicable
pass through trustee will mail to each DTC participant holding certificates the
statement described above and will make available additional copies as requested
by the DTC participants for forwarding to certificate owners.

      After the end of each calendar year, each pass through trustee will
prepare a report for each person that was a holder of one or more of its pass
through certificates at any time during the


                                       14

preceding calendar year. This report will contain the sum of the amount of
distributions allocable to principal, premium and interest with respect to that
pass through trust for the preceding calendar year or, if the person was a
holder of a pass through certificate during only a portion of the preceding
calendar year, for the applicable portion of the preceding calendar year. In
addition, each pass through trustee will prepare for each person that was a
holder of one or more of its pass through certificates at any time during the
preceding calendar year any other information that are readily available to the
pass through trustee and which a certificateholder reasonably requests as
necessary for the purpose of preparing its federal income tax returns. The
reports and other items described in this section will be prepared on the basis
of information supplied to the pass through trustee by DTC participants and will
be delivered by the pass through trustee to DTC participants to be available for
forwarding by DTC participants to certificate owners in the manner described
above.

      If the certificates of a pass through trust are issued in the form of
physical certificates, the pass through trustee of that pass through trust will
prepare and deliver the information described above to each record holder of a
pass through certificate issued by that pass through trust as the name and
period of ownership of the holder appears on the records of the registrar of the
certificates.

VOTING OF EQUIPMENT NOTES

      A pass through trustee has the right to vote and give consents and waivers
with respect to the equipment notes held by that pass through trust. However,
the pass through trustee's right to vote and give consents or waivers may be
restricted or may be exercisable by another person in accordance with the terms
of an intercreditor agreement, as described in the applicable prospectus
supplement. The pass through trust agreement will set forth:

      -     the circumstances in which a pass through trustee may direct any
action or cast any vote with respect to the equipment notes held for its pass
through trust at its own discretion;

      -     the circumstances in which a pass through trustee will seek
instructions from its certificateholders; and

      -     if applicable, the percentage of certificateholders required to
direct the pass through trustee to take action.

      If the holders of certificates are entitled to the benefits of a liquidity
facility, and the liquidity facility is used to make any payments to
certificateholders, the provider of the liquidity facility may be entitled to
exercise rights to vote or give consents and waivers with respect to the
equipment notes held for the pass through trust that issued the certificates, as
described in the applicable prospectus supplement.

EVENTS OF DEFAULT AND CERTAIN RIGHTS UPON AN EVENT OF DEFAULT

      The prospectus supplement will specify the events of default that can
occur under the pass through trust agreement and under the indentures relating
to the equipment notes held for the related pass through trust. In the case of a
leased aircraft indenture, an indenture default will


                                       15

include events of default under the related lease. In the case of any equipment
notes that are supported by a liquidity facility, a default may include events
of default under that liquidity facility.

      Unless otherwise provided in a prospectus supplement, all of the equipment
notes issued under the same indenture will relate to a specific aircraft and
there will be no cross-collateralization or cross-default provisions in the
indentures. As a result, events resulting in a default under any particular
indenture will not necessarily result in an a default under any other indenture.
If a default occurs in fewer than all of the indentures, payments of principal
and interest on the equipment notes issued under the indentures with respect to
which a default has not occurred will continue to be made as originally
scheduled.

      As described below under "-- Cross-Subordination Issues," a prospectus
supplement may describe the terms of any cross-subordination provisions among
certificateholders of separate pass through trusts. If cross-subordination is
provided, payments made pursuant to an indenture under which a default has not
occurred may be distributed first to the holders of the certificates issued
under the pass through trust which holds the most senior equipment notes issued
under all of the indentures.

      The ability of the applicable owner trustee or owner participant under a
leased aircraft indenture to cure a default under the indenture, including a
default that results from the occurrence of a default under the related lease,
will be described in the prospectus supplement. Unless otherwise provided in a
prospectus supplement, with respect to any pass through certificates or
equipment notes entitled to the benefits of a liquidity facility, a drawing
under the liquidity facility for the purpose of making a payment of interest as
a result of our failure to have made a corresponding payment will not cure a
default related to our failure.

      The prospectus supplement related to a series of pass through certificates
will describe the circumstances under which the pass through trustee of the
related pass through trust may vote some or all of the equipment notes held in
the pass through trust. The prospectus supplement also will set forth the
percentage of certificateholders of the pass through trust entitled to direct
the pass through trustee to take any action with respect to the equipment notes.
If the equipment notes outstanding under an indenture are held by more than one
pass through trust, then the ability of the certificateholders issued with
respect to any one pass through trust to cause the loan trustee with respect to
any equipment notes held in the pass through trust to accelerate the equipment
notes under the applicable indenture or to direct the exercise of remedies by
the loan trustee under the applicable indenture will depend, in part, upon the
proportion of the aggregate principal amount of the equipment notes outstanding
under that indenture and held in that pass through trust to the aggregate
principal amount of all equipment notes outstanding under that indenture.

      In addition, if cross-subordination provisions are applicable to any
series of certificates, then the ability of the certificateholders of any one
pass through trust holding equipment notes issued under an indenture to cause
the loan trustee with respect to any equipment notes held in that pass through
trust to accelerate the equipment notes under that indenture or to direct the
exercise of remedies by the loan trustee under that indenture will depend, in
part, upon the class of equipment notes held in the pass through trust. If the
equipment notes outstanding under an indenture are held by more than one pass
through trust, then each pass through trust will hold equipment notes with
different terms from the equipment notes held in the other pass through trusts
and therefore the


                                       16

certificateholders of each pass through trust may have divergent or conflicting
interests from those of the certificateholders of the other pass through trusts
holding equipment notes issued under the same indenture. In addition, so long as
the same institution acts as pass through trustee of each pass through trust, in
the absence of instructions from the certificateholders of any pass through
trust, the pass through trustee for the pass through trust could for the same
reason be faced with a potential conflict of interest upon a default under an
indenture. In that event, the pass through trustee has indicated that it would
resign as pass through trustee of one or all the pass through trusts, and a
successor trustee would be appointed in accordance with the terms of the Basic
Agreement.

      The prospectus supplement for a series of certificates will specify
whether and under what circumstances the pass through trustee may sell for cash
to any person all or part of the equipment notes held in the related pass
through trust. Any proceeds received by the pass through trustee upon a sale
will be deposited in an account established by the pass through trustee for the
benefit of the certificateholders of the pass through trust for the deposit of
the special payments and will be distributed to the certificateholders of the
pass through trust on a special distribution date.

      The market for equipment notes in default may be very limited, and we
cannot assure you that they could be sold for a reasonable price. Furthermore,
so long as the same institution acts as pass through trustee of multiple pass
through trusts, it may be faced with a conflict in deciding from which pass
through trust to sell equipment notes to available buyers. If the pass through
trustee sells any equipment notes with respect to which a default under an
indenture exists for less than their outstanding principal amount, the
certificateholders of that pass through trust will receive a smaller amount of
principal distributions than anticipated and will not have any claim for the
shortfall against us, any owner trustee, owner participant or the pass through
trustee. Furthermore, neither the pass through trustee nor the
certificateholders of that pass through trust could take any action with respect
to any remaining equipment notes held in that pass through trust so long as no
default under an indenture exists.

      Any amount, other than scheduled payments received on a regular
distribution date, distributed to the pass through trustee of any pass through
trust by the loan trustee under any indenture on account of the equipment notes
held in that pass through trust following a default under such indenture will be
deposited in the special payments account for that pass through trust and will
be distributed to the certificateholders of that pass through trust on a special
distribution date. In addition, if a prospectus supplement provides that the
applicable owner trustee may, under circumstances specified in the prospectus
supplement, redeem or purchase the outstanding equipment notes issued under the
applicable indenture, the price paid by the owner trustee to the pass through
trustee of any pass through trust for the equipment notes issued under that
indenture and held in that pass through trust will be deposited in the special
payments account for the pass through trust and will be distributed to the
certificateholders of the pass through trust on a special distribution date.

      Any funds representing payments received with respect to any equipment
notes in default held in a pass through trust, or the proceeds from the sale by
the pass through trustee of any of those equipment notes, held by the pass
through trustee in the special payments account for that pass through trust
will, to the extent practicable, be invested and reinvested by the pass through


                                       17

trustee in permitted investments pending the distribution of the funds on a
special distribution date. Permitted investments will be specified in the
related prospectus supplement.

      The Basic Agreement provides that the pass through trustee of each pass
through trust will give to the certificateholders of that pass through trust
notice of all uncured or unwaived defaults known to it with respect to that pass
through trust. The Basic Agreement requires the pass through trustee to provide
the notice of default within 90 days after the occurrence of the default.
However, except in the case of default in the payment of principal, premium, if
any, or interest on any of the equipment notes held for a pass through trust,
the pass through trustee will be protected in withholding a notice of default if
it in good faith determines that withholding the notice is in the interest of
the certificateholders of such pass through trust. The term "default" as used in
this paragraph means only the occurrence of a default under an indenture with
respect to equipment notes held in a pass through trust as described above,
except that in determining whether any default under an indenture has occurred,
any related grace period or notice will be disregarded.

      The Basic Agreement requires the pass through trustee to act with a
specified standard of care while a default is continuing under an indenture. In
addition, the Basic Agreement contains a provision entitling the pass through
trustee to require reasonable security or indemnification by the
certificateholders of the pass through trust before proceeding to exercise any
right or power under the Basic Agreement at the request of those
certificateholders.

      The prospectus supplement for a series of certificates will specify the
percentage of certificateholders entitled to waive, or to instruct the pass
through trustee to waive, any past default with respect to the related pass
through trust and its consequences. The prospectus supplement for a series of
certificates also will specify the percentage of certificateholders entitled to
waive, or to instruct the pass through trustee or the loan trustee to waive, any
past default under an indenture.

MERGER, CONSOLIDATION AND TRANSFER OF ASSETS

      We will be prohibited from consolidating with or merging into any other
corporation or transferring substantially all of our assets as an entirety to
any other corporation unless the surviving, successor or transferee corporation:

      -     is validly existing under the laws of the United States or any of
its states;

      -     is a citizen of the United States, as defined in Title 49 of the
U.S. Code relating to aviation, referred to as the "Transportation Code,"
holding an air carrier operating certificate issued pursuant to Chapter 447 of
Title 49, U.S. Code, if, and so long as, that status is a condition of
entitlement to the benefits of Section 1110 of the U.S. Bankruptcy Code relating
to the rights of creditors of an airline in the event of the airline's
bankruptcy; and

      -     expressly assumes all of our obligations contained in the Basic
Agreement and any pass through trust supplement, the note purchase agreements,
any indentures, any participation agreements and, with respect to aircraft
leased by us, the applicable leases.

      In addition, we will be required to deliver a certificate and an opinion
or opinions of counsel indicating that the transaction, in effect, complies with
these conditions.


                                       18

MODIFICATIONS OF THE BASIC AGREEMENT

      The Basic Agreement contains provisions permitting us and the pass through
trustee of each pass through trust to enter into a supplemental trust agreement,
without the consent of the holders of any of the certificates issued by such
pass through trust, in order to do the following, among other things:

      -     to provide for the formation of such pass through trust and the
issuance of a series of certificates and to set forth the terms of the
certificates;

      -     to evidence the succession of another corporation to us and the
assumption by that corporation of our obligations under the Basic Agreement and
the pass through trust agreements;

      -     to add to our covenants for the benefit of holders of such
certificates, or to surrender any right or power in the Basic Agreement
conferred upon us;

      -     to cure any ambiguity or correct or supplement any defective or
inconsistent provision of the Basic Agreement or any pass through trust
agreement, so long as those changes will not materially adversely affect the
interests of the holders of such certificates, or to cure any ambiguity or
correct any mistake or, to give effect to or provide for replacement liquidity
facilities, if applicable, to such certificates;

      -     to comply with any requirement of the SEC, any applicable law, rules
or regulations of any exchange or quotation system on which any certificates may
be listed or of any regulatory body;

      -     to modify, eliminate or add to the provisions of the Basic Agreement
to the extent necessary to continue the qualification of the pass through trust
agreement under the Trust Indenture Act of 1939, and to add to the Basic
Agreement other provisions as may be expressly permitted by the Trust Indenture
Act;

      -     to provide for a successor pass through trustee or to add to or
change any provision of the Basic Agreement as necessary to facilitate the
administration of the pass through trusts created under the pass through trust
agreement by more than one pass through trustee; and

      -     to make any other amendments or modifications to the Basic Agreement
so long as those amendments or modifications apply only to certificates of a
series issued after the date of the amendment or modification.

      No pass through trust supplement may be made that will adversely affect
the status of any pass through trust as a grantor trust for U.S. federal income
tax purposes.

      The Basic Agreement also contains provisions permitting us and the pass
through trustee of each pass through trust, with the consent of a majority in
interest of the certificateholders of the pass through trust, to execute
supplemental trust agreements adding any provisions to or changing or
eliminating any of the provisions of the Basic Agreement, to the extent relating
to that pass through trust, and the applicable pass through trust supplement, or
modifying the rights of the


                                       19

certificateholders, except that no supplement may, without the consent of each
affected certificateholder:

      -     reduce in any manner the amount of, or delay the timing of, any
receipt by the pass through trustee of payments on the equipment notes held in
the pass through trust or distributions in respect of any pass through
certificate issued by the pass through trust;

      -     change the date or place of any payment in respect of any pass
through certificate, or make distributions payable in currency other than that
provided for in the certificates, or impair the right of any certificateholder
to institute suit for the enforcement of any payment when due;

      -     permit the disposition of any equipment note held in the pass
through trust, except as provided in the pass through trust agreement, or
otherwise deprive any certificateholder of the benefit of the ownership of the
applicable equipment note;

      -     reduce the percentage of the aggregate fractional undivided
interests of the pass through trust that is required in order for any supplement
or waiver to be approved;

      -     modify any of the provisions relating to the rights of the
certificateholders in respect of the waiver of events of default or receipt of
payment;

      -     alter the priority of distributions described in any applicable
intercreditor agreement, in a manner materially adverse to the interests of the
certificateholders of such pass through trust; or

      -     adversely affect the status of any pass through trust as a grantor
trust for U.S. federal income tax purposes.

MODIFICATION OF INDENTURE AND RELATED AGREEMENTS

      The prospectus supplement will specify the pass through trustee's
obligations if a pass through trustee, as the holder of any equipment notes held
for a pass through trust, receives a request for its consent to any amendment,
modification or waiver under the indenture under which the equipment notes were
issued, under the lease relating to the aircraft leased by us that was financed
with the proceeds of the equipment notes or under any liquidity facility.

CROSS-SUBORDINATION ISSUES

      The equipment notes issued under an indenture may be held in more than one
pass through trust, and one pass through trust may hold equipment notes issued
under more than one indenture. Unless otherwise provided in a prospectus
supplement, only equipment notes having the same priority for distributions
under the applicable indenture may be held in the same pass through trust. In
that event, payments made on account of a subordinate class of certificates
issued under a prospectus supplement may be subordinated, under circumstances
described in the prospectus supplement, to the prior payment of all amounts
owing to certificateholders of a pass through trust which holds senior equipment
notes issued under the applicable indentures. The prospectus supplement related
to an issuance of certificates will describe the "cross-subordination"
provisions


                                       20

and any related terms, including the percentage of certificateholders under any
pass through trust which are permitted to:

      -     grant waivers of defaults under any applicable indenture;

      -     consent to the amendment or modification of any applicable
indenture; or

      -     direct the exercise of remedial actions under any applicable
indenture.

TERMINATION OF THE PASS THROUGH TRUSTS

      Our obligations and those of the pass through trustee with respect to a
pass through trust will terminate upon the distribution to certificateholders of
the pass through trust of all amounts required to be distributed to them
pursuant to the applicable pass through trust agreement and the disposition of
all property held in the pass through trust. In no event will any pass through
trust continue beyond 110 years following the date of the execution of the
applicable pass through trust supplement, or any other final expiration date as
may be specified in the pass through trust supplement. The pass through trustee
will send to each certificateholder of record of the pass through trust notice
of the termination of the pass through trust, the amount of the proposed final
payment and the proposed date for the distribution of the final payment for the
pass through trust. The final distribution to any certificateholder of the pass
through trust will be made only upon surrender of that certificateholder's
certificates at the office or agency of the pass through trustee specified in
the notice of termination.

DELAYED PURCHASE OF EQUIPMENT NOTES

      On the issuance date of any certificates, if all of the proceeds from the
sale of the certificates are not used to purchase the equipment notes
contemplated to be held in the related pass through trust, the equipment notes
may be purchased by the pass through trustee at any time on or prior to the date
specified in the applicable prospectus supplement. In that event, the proceeds
from the sale of the certificates not used to purchase equipment notes will be
held under an arrangement described in the applicable prospectus supplement
pending the purchase of equipment notes. The arrangements with respect to the
payment of interest on funds so held will be described in the applicable
prospectus supplement. If any proceeds are not used to purchase equipment notes
by the date specified in the applicable prospectus supplement, the proceeds will
be returned to the certificateholders.

LIQUIDITY FACILITY

      The related prospectus supplement may provide that one or more payments of
interest on the certificates of one or more series will be supported by a
liquidity facility issued by an institution identified in the related prospectus
supplement. The provider of the liquidity facility may have a claim on money and
property belonging to a pass through trust that is senior to the
certificateholders' as specified in the related prospectus supplement.


                                       21

THE PASS THROUGH TRUSTEE

      Unless otherwise provided in the prospectus supplement for any series of
certificates, the pass through trustee for each series of certificates will be
Wilmington Trust Company. With certain exceptions, the pass through trustee
makes no representations as to the validity or sufficiency of the Basic
Agreement, the pass through trust supplements, the certificates, the equipment
notes, the indentures, the leases or other related documents. The pass through
trustee will not be liable with respect to any series of certificates for any
action taken or omitted to be taken by it in good faith in accordance with the
direction of the holders of a majority in principal amount of outstanding
certificates of that series issued under the Basic Agreement. Subject to those
provisions, the pass through trustee will be under no obligation to exercise any
of its rights or powers under the Basic Agreement at the request of any holders
of certificates issued under that agreement unless they will have offered to the
pass through trustee indemnity satisfactory to it. The Basic Agreement provides
that the pass through trustee in its individual or any other capacity may
acquire and hold certificates and, subject to certain conditions, may otherwise
deal with us and, with respect to the leased aircraft, with any owner trustee
with the same rights it would have if it were not the pass through trustee.

      The pass through trustee may resign with respect to any or all of the pass
through trusts at any time, in which event we will be obligated to appoint a
successor trustee. If the pass through trustee ceases to be eligible to continue
as pass through trustee with respect to a pass through trust or becomes
incapable of acting as pass through trustee or becomes insolvent, we may remove
the pass through trustee, or any certificateholder of the pass through trust for
at least six months may, on behalf of himself and all others similarly situated,
petition any court of competent jurisdiction for the removal of the pass through
trustee and the appointment of a successor trustee. Any resignation or removal
of the pass through trustee with respect to a pass through trust and appointment
of a successor trustee for the pass through trust does not become effective
until acceptance of the appointment by the successor trustee. Pursuant to the
resignation and successor trustee provisions, it is possible that a different
trustee could be appointed to act as the successor trustee with respect to each
pass through trust. All references in this prospectus to the pass through
trustee should be read to take into account the possibility that the pass
through trusts could have different successor trustees in the event of a
resignation or removal.

      The Basic Agreement provides that we will pay the pass through trustee's
fees and expenses and indemnify the pass through trustee against certain
liabilities.

                       DESCRIPTION OF THE EQUIPMENT NOTES

      The statements made under this caption are summaries, and we refer you to
the entire prospectus and detailed information appearing in the applicable
prospectus supplement. Where no distinction is made between the leased aircraft
notes and the owned aircraft notes or between their respective indentures, those
statements refer to any equipment notes and any indenture.

      To the extent that any provision in any prospectus supplement is
inconsistent with any provision in this summary, the provision of the prospectus
supplement will control.


                                       22

GENERAL

      The equipment notes will be issued under indentures. Equipment notes
secured by an aircraft that is leased to us will be issued under an indenture
between an owner trustee and a loan trustee. Equipment notes secured by an
aircraft that is owned by us will be issued under an indenture between a loan
trustee and us.

      The leased aircraft notes will be non-recourse obligations of the
applicable owner trustee. All of the leased aircraft notes issued under the same
indenture will relate to and will be secured by one or more specific aircraft
leased to us. Unless otherwise specified in the applicable prospectus
supplement, leased aircraft notes will not be secured by any other aircraft. We
will be the issuer of owned aircraft notes. The owned aircraft notes will be our
direct recourse obligations. All of the owned aircraft notes issued under the
same indenture will relate to, and will be secured by, one or more specific
aircraft that we own. Unless otherwise specified in the applicable prospectus
supplement, the owned aircraft notes will not be secured by any other aircraft.

PRINCIPAL AND INTEREST PAYMENTS

      Interest received by the pass through trustee on the equipment notes held
in a pass through trust will be passed through to the certificateholders of that
pass through trust on the dates and at the annual rate set forth in the
applicable prospectus supplement until the final distribution for that pass
through trust. Principal payments received by the pass through trustee on the
equipment notes held in a pass through trust will be passed through to the
certificateholders of that pass through trust in scheduled amounts on the dates
set forth in the applicable prospectus supplement until the final distribution
date for that pass through trust.

      If any date scheduled for any payment of principal, premium, if any, or
interest with respect to the equipment notes is not a business day, the payment
will be made on the next succeeding business day without any additional
interest.

REDEMPTION

      The applicable prospectus supplement will describe the circumstances,
whether voluntary or involuntary, under which the equipment notes may be
redeemed or purchased prior to their stated maturity date, in whole or in part.
The prospectus supplement will also describe the premium, if any, applicable
upon redemptions or purchases and other terms applying to the redemptions or
purchases of the equipment notes.

SECURITY

      The leased aircraft notes will be secured by:

      -     an assignment by the related owner trustee to the related loan
trustee of the owner trustee's rights, except for certain rights described
below, under the lease or leases with respect to the related aircraft, including
the right to receive payments of rent under those leases; and

      -     a mortgage granted to the loan trustee on the aircraft, subject to
our rights under the lease or leases.


                                       23

      Under the terms of each lease, our obligations in respect of each leased
aircraft will be those of a lessee under a "net lease." Accordingly, we will be
obligated, among other things and at our expense, to cause each leased aircraft
to be duly registered, to pay all costs of operating the aircraft and to
maintain, service, repair and overhaul the aircraft or cause it to be
maintained, serviced, repaired and overhauled. With respect to the leased
aircraft, the assignment by the related owner trustee to the related loan
trustee of its rights under the related lease will exclude, among other things:

      -     rights of the owner trustee and the related owner participant
relating to indemnification by us for certain matters;

      -     insurance proceeds payable to the owner trustee in its individual
capacity and to the owner participant under liability insurance maintained by us
pursuant to the lease or by the owner trustee or the owner participant;

      -     insurance proceeds payable to the owner trustee in its individual
capacity or to the owner participant under certain casualty insurance maintained
by the owner trustee or the owner participant pursuant to the lease; and

      -     any rights of the owner participant or the owner trustee to enforce
payment of the foregoing amounts and their respective rights to the proceeds of
the foregoing.

      The owned aircraft notes will be secured by a mortgage granted to the
related loan trustee of all of our right, title and interest in and to the owned
aircraft. Under the terms of each owned aircraft indenture, we will be
obligated, among other things and at our expense, to cause each owned aircraft
to be duly registered, to pay all costs of operating the aircraft and to
maintain, service, repair and overhaul the aircraft or cause it to be
maintained, serviced, repaired and overhauled.

      We will be required, except under certain circumstances, to keep each
aircraft registered under the Transportation Code, and to record the indenture
and the lease, if applicable, among other documents, with respect to each
aircraft under the Transportation Code. Recordation of the indenture, the lease,
if applicable, and other documents with respect to each aircraft will give the
related loan trustee a perfected security interest in the related aircraft
whenever it is located in the United States or any of its territories and
possessions. The Convention on the International Recognition of Rights in
Aircraft, referred to as the "Convention," provides that this security interest
will also be recognized, with certain limited exceptions, in those jurisdictions
that have ratified or adhere to the Convention.

      We will have the right, subject to certain conditions, at our own expense
to register each aircraft in countries other than the United States. Each
aircraft may also be operated by us or under lease, sublease or interchange
arrangements in countries that are not parties to the Convention. The extent to
which the related loan trustee's security interest would be recognized in an
aircraft located in a country that is not a party to the Convention, and the
extent to which the security interest would be recognized in a jurisdiction
adhering to the Convention if the aircraft is registered in a jurisdiction not a
party to the Convention, is uncertain. Moreover, in the case of a default under
an indenture, the ability of the related loan trustee to realize upon its
security interest in an aircraft


                                       24

could be adversely affected as a legal or practical matter if the aircraft were
registered or located outside the United States.

      Unless otherwise specified in the applicable prospectus supplement, the
equipment notes will not be cross-collateralized. Consequently, the equipment
notes issued in respect of any one aircraft will not be secured by any other
aircraft. Unless and until a default under an indenture with respect to a leased
aircraft has occurred and is continuing, the related loan trustee may exercise
only limited rights of the related owner trustee under the related lease. The
loan trustee will invest and reinvest funds, if any, held by it from time to
time under an indenture. The loan trustee will, at our direction, invest and
reinvest funds in certain investments described in the applicable indenture. We
will not be entitled to direct the loan trustee to invest and reinvest funds
with respect to a leased aircraft in the case of a default under the applicable
lease or, with respect to an owned aircraft, in the case of a default under the
applicable indenture. We will pay the net amount of any loss resulting from
these investments.

      In the case of Chapter 11 bankruptcy proceedings involving a holder of
"equipment" (defined as described below), Section 1110 of the U.S. Bankruptcy
Code provides special rights to lessors, conditional vendors and holders of
security interests with respect to such equipment. Under Section 1110, the right
of such financing parties to take possession of such equipment in compliance
with the provisions of a lease, conditional sale contract or security agreement
is not affected by any provision of the U.S. Bankruptcy Code or any power of the
bankruptcy court. Ordinarily, such right would be limited by the "automatic
stay" under the Bankruptcy Code. Such right to take possession may not be
exercised for 60 days following the date of commencement of the reorganization
proceedings. Thereafter, such right to take possession may be exercised during
such proceedings unless, within the 60-day period or any longer period consented
to by the relevant parties, the debtor agrees to perform its obligations that
become due on or after that date and cures all defaults on a timely basis.
Defaults resulting solely from the financial condition, bankruptcy, insolvency
or reorganization of the debtor need not be cured.

      "Equipment" is defined in Section 1110 of the U.S. Bankruptcy Code, in
part, as an aircraft, aircraft engine, propeller, appliance, or spare part (as
defined in Section 40102 of Title 49 of the U.S. Code) that is subject to a
security interest granted by, leased to, or conditionally sold to a debtor that,
at the time such transaction is entered into, holds an air carrier operating
certificate issued pursuant to chapter 447 of title 49 of the U.S. Code for
aircraft capable of carrying 10 or more individuals or 6,000 pounds of more of
cargo (subject to certain limitations in the case of equipment first placed in
service on or prior to October 22, 1994).

      In connection with any issuance of certificates under this prospectus and
the applicable prospectus supplement, it will be a condition to the pass through
trustee's obligation to purchase equipment notes with respect to each aircraft
that our outside counsel provide its opinion (which may assume that we hold, at
the time of the lease or mortgage, as the case may be, an air carrier operating
certificate issued pursuant to chapter 447 of title 49 of the U.S. Code for
aircraft capable of carrying 10 or more individuals or 6,000 pounds or more of
cargo) to the Pass Through Trustee that:

      -     if the aircraft is a leased aircraft, the owner trustee, as lessor
under the lease for the aircraft, and the loan trustee, as assignee of the owner
trustee's rights under the lease pursuant to


                                       25

the applicable indenture, will be entitled to the benefits of Section 1110 of
the U.S. Bankruptcy Code with respect to the airframe and engines comprising the
aircraft; or

      -     if the aircraft is an owned aircraft, the loan trustee will be
entitled to the benefits of Section 1110 with respect to the airframe and
engines comprising the owned aircraft.

      The opinion will not address the possible replacement of an aircraft after
an "Event of Loss," as defined in the applicable indenture, in the future.

RANKING OF EQUIPMENT NOTES

      Some of the equipment notes related to one or more aircraft, as described
in the related prospectus supplement, may be subordinated and junior in right of
payment to other equipment notes related to the same aircraft. The terms of the
subordination, if any, will be described in the related prospectus supplement.

PAYMENTS AND LIMITATION OF LIABILITY

      We will lease each leased aircraft from an owner trustee for a term
commencing on the delivery date of the aircraft to the owner trustee and
expiring on a date no earlier than the latest maturity date of the related
leased aircraft notes, unless previously terminated as permitted by the terms of
the related lease. We will make basic rent and other payments under each lease
to an owner trustee, as lessor. The owner trustee will assign these payments
under the applicable indenture to the related loan trustee to provide the funds
necessary to pay principal of, premium, if any, and interest due from the owner
trustee on the leased aircraft notes issued under the indenture. Each lease will
provide that under no circumstances will our rent payments be less than the
scheduled payments on the related leased aircraft notes. The balance of any
basic rent payment under each lease, after payment of amounts due on the leased
aircraft notes issued under the indenture corresponding to the lease, will be
paid over to the applicable owner trustee. Our obligation to pay rent and to
cause other payments to be made under each lease will be our direct obligation.
Except in circumstances in which we purchase a leased aircraft and assume the
related leased aircraft notes, the leased aircraft notes will not be our direct
obligation. None of the owner trustees, the owner participants or the loan
trustees will be personally liable to any holder of leased aircraft notes for
amounts payable under the leased aircraft notes. Except as provided in the
indentures relating to the leased aircraft notes, no owner trustee or loan
trustee will be liable for or incur any liability under the indentures. Except
in the circumstances described above, all amounts payable under any leased
aircraft notes, other than payments made in connection with an optional
redemption or purchase by the related owner trustee or the related owner
participant, will be made only from:

      -     the assets subject to the lien of the applicable indenture with
respect to the aircraft or the income and proceeds received by the related loan
trustee from that aircraft, including rent payable by us under the related
lease; or

      -     if so provided in the related prospectus supplement, the applicable
liquidity facility.


                                       26

      With respect to the leased aircraft notes, except as otherwise provided in
the applicable indenture, no owner trustee will be personally liable for any
amount payable or for any statements, representations, warranties, agreements or
obligations under any indenture or under any leased aircraft notes. None of the
owner participants will have any duty or responsibility under the leased
aircraft indentures or under the leased aircraft notes to the related loan
trustee or to any holder of any leased aircraft note.

      Our obligations under each owned aircraft indenture and under the owned
aircraft notes will be our direct obligations.

DEFEASANCE OF THE INDENTURES AND THE EQUIPMENT NOTES IN CERTAIN CIRCUMSTANCES

      Unless otherwise specified in the applicable prospectus supplement, an
indenture may provide that the obligations of the related loan trustee, the
related owner trustee or us, as the case may be, under that indenture will be
deemed to have been discharged and paid in full on the 91st day after the date
that money or certain United States government securities, in an aggregate
amount sufficient to pay when due (including as a consequence of redemption in
respect of which notice is given on or prior to the date of the deposit)
principal, premium, if any, and interest on all equipment notes issued under
that indenture, are irrevocably deposited with the related loan trustee. The
discharge may occur only if, among other things, there has been published by the
IRS a ruling to the effect that holders of the equipment notes will not
recognize income, gain or loss for federal income tax purposes as a result of
the deposit, defeasance and discharge and will be subject to federal income tax
on the same amount and in the same manner and at the same time as would have
been the case if the deposit, defeasance and discharge had not occurred.

      Upon defeasance of the equipment notes, or upon payment in full of the
principal of, premium, if any, and interest on all equipment notes issued under
any indenture on the applicable maturity date, or upon deposit with the
applicable loan trustee of sufficient money no earlier than one year prior to
the date of maturity, the holders of the equipment notes will have no beneficial
interest in or other rights with respect to the related aircraft or other assets
subject to the lien of the indenture and the lien will terminate.

ASSUMPTION OF OBLIGATIONS BY SOUTHWEST

      Unless otherwise specified in the applicable prospectus supplement, upon
our purchase of any leased aircraft prior to the end of the applicable term, we
may assume on a full recourse basis all of the obligations of the owner trustee,
other than its obligations in its individual capacity, under the indenture and
the leased aircraft notes relating to that lease. If we assume leased aircraft
notes, provisions relating to maintenance, possession and use of the related
aircraft, liens and insurance will be incorporated into the indenture. If we
assume leased aircraft notes in connection with our purchase of a leased
aircraft, leased aircraft notes issued under the indenture will not be redeemed
and will continue to be secured by the aircraft.

LIQUIDITY FACILITY

      The related prospectus supplement may provide that one or more payments of
interest on the related equipment notes of one or more series will be supported
by a liquidity facility issued by an institution identified in the related
prospectus supplement. Unless otherwise provided in the


                                       27

related prospectus supplement, the provider of the liquidity facility will have
a claim upon the assets securing the equipment notes senior to the claim of the
pass through trustee, as owner of the equipment notes.

INTERCREDITOR ISSUES

      Equipment notes may be issued in different classes, which means that the
equipment notes may have different payment priorities even though they are
issued by the same borrower and relate to the same aircraft. If multiple classes
of equipment notes are issued, the related prospectus supplement will describe
the priority of distributions among the equipment notes, any liquidity
facilities, the ability of any class to exercise and/or enforce any or all
remedies with respect to the related aircraft, and, if the equipment notes are
leased aircraft notes, the related lease, and certain other intercreditor terms
and provisions.

             CERTAIN UNITED STATES FEDERAL INCOME TAX CONSEQUENCES

GENERAL

      Unless otherwise indicated in the applicable prospectus supplement, the
following summary describes all material generally applicable U.S. federal
income tax consequences to certificateholders of the purchase, ownership and
disposition of the certificates offered by this prospectus, and in the opinion
of Vinson & Elkins L.L.P., our special tax counsel, is accurate in all material
respects with respect to the matters discussed in this prospectus. Except as
otherwise specified, the summary is addressed to beneficial owners of
certificates that are citizens or residents of the United States, corporations,
partnerships or other entities created or organized in or under the laws of the
United States or any state therein, or estates or trusts the income of which is
subject to U.S. federal income taxation regardless of its source, and that will
hold the certificates as capital assets.

      This summary does not address the tax treatment of U.S. certificateholders
that may be subject to special tax rules, such as banks, insurance companies,
dealers in securities or commodities, tax-exempt entities, holders that will
hold certificates as part of a straddle or holders that have a "functional
currency" other than the U.S. dollar, nor, except as specifically indicated,
does it address the tax treatment of U.S. certificateholders that do not acquire
certificates at the public offering price as part of the initial offering. The
summary is not a comprehensive description of all of the tax considerations that
may be relevant to a decision to purchase certificates. This summary does not
describe any tax consequences arising under the laws of any state, locality or
taxing jurisdiction other than the United States, nor does it describe any
estate or gift tax consequences.

      The summary is based upon the tax laws and practice of the United States
as in effect on the date of this prospectus, as well as judicial and
administrative interpretations, in final or proposed form, available on or
before that date. Changes to the existing laws could apply retroactively and
could alter the tax consequences discussed below. We have not sought any ruling
from the IRS with respect to the federal income tax consequences, discussed
below, and we cannot assure you that the IRS will not take contrary positions.
The pass through trusts are not indemnified for any federal income taxes that
may be imposed upon them, and the imposition of any such taxes on a


                                       28

pass through trust could result in a reduction in the amounts available for
distribution to the certificateholders of that pass through trust. Prospective
investors should consult their own tax advisors with respect to the federal,
state, local and foreign tax consequences to them of the purchase, ownership and
disposition of the certificates.

TAX STATUS OF THE PASS THROUGH TRUSTS

      In the opinion of our special tax counsel, each pass through trust will be
classified as a grantor trust for U.S. federal income tax purposes.

TAXATION OF CERTIFICATEHOLDERS GENERALLY

      A U.S. certificateholder will be treated as owning its pro rata undivided
interest in each of the equipment notes and any other property held by the
related pass through trust. Accordingly, each U.S. certificateholder's share of
interest paid on the equipment notes will be taxable as ordinary income, as it
is paid or accrued, in accordance with such U.S. certificateholder's method of
accounting, and a U.S. certificateholder's share of any premium paid on
redemption of an equipment note will be treated as capital gain. If a pass
through trust is supported by a liquidity facility, any amounts received by the
pass through trust under the liquidity facility with respect to unpaid interest
will be treated for U.S. federal income tax purposes as having the same
characteristics as the payments they replace. If we assume an owner trust's
obligations under leased aircraft notes, the assumption would be treated for
federal income tax purposes as a taxable exchange of the leased aircraft notes,
resulting in recognition of gain or loss by the U.S. certificateholder.

      Each U.S. certificateholder will be entitled to deduct, consistent with
its method of accounting, its pro rata share of fees and expenses paid or
incurred by the corresponding pass through trust as provided in Section 162 or
212 of the Internal Revenue Code of 1986, as amended, referred to herein as the
"Code." Certain fees and expenses, including fees paid to the pass through
trustee and the provider of the liquidity facility, if applicable, will be paid
by parties other than the certificateholders. These fees and expenses could be
treated as constructively received by the pass through trust, in which event a
U.S. certificateholder will be required to include in income and will be
entitled to deduct its pro rata share of the fees and expenses. If a U.S.
certificateholder is an individual, estate or trust, the deduction for the
certificateholder's share of fees or expenses will be allowed only to the extent
that all of the certificateholder's miscellaneous itemized deductions, including
the certificateholder's share of fees and expenses, exceed 2% of the
certificateholder's adjusted gross income. In addition, in the case of U.S.
certificateholders who are individuals, certain otherwise allowable itemized
deductions will be subject generally to additional limitations on itemized
deductions under applicable provisions of the Code.

EFFECT OF SUBORDINATION OF CERTIFICATEHOLDERS OF SUBORDINATED TRUSTS

      If any pass through trust is subordinated in right of payment to any other
pass through trust and the subordinated trust receives less than the full amount
of the interest, principal or premium paid with respect to the equipment notes
held by it because of the subordination of such pass through trust, the
certificateholders of the subordinated trust would probably be treated for
federal income tax purposes as if they had:


                                       29

      -     received as distributions their full share of interest, principal,
or premium;

      -     paid over to the preferred class of certificateholders an amount
equal to their share of the amount of the shortfall; and

      -     retained the right to reimbursement of the amount of the shortfall
to the extent of future amounts payable to the certificateholders of the
subordinated trust on account of the shortfall.

      Under this analysis:

      -     subordinated certificateholders incurring a shortfall would be
required to include as current income any interest or other income of the
subordinated trust that was a component of the shortfall, even though that
amount was in fact paid to a preferred class of certificateholders;

      -     a loss would only be allowed to subordinated certificateholders when
their right to receive reimbursement of the shortfall becomes worthless; that
is, when it becomes clear that funds will not be available from any source to
reimburse the shortfall; and

      -     reimbursement of the shortfall before a claim of worthlessness would
not be taxable income to certificateholders because the amount reimbursed would
have been previously included in income.

      These results should not significantly affect the inclusion of income for
certificateholders on the accrual method of accounting, but could accelerate
inclusion of income to certificateholders on the cash method of accounting by,
in effect, placing them on the accrual method.

ORIGINAL ISSUE DISCOUNT

      The equipment notes may be issued with original issue discount, referred
to as OID. The prospectus supplement will state whether any equipment notes to
be held by the related pass through trust will be issued with OID. Generally, a
holder of a debt instrument issued with OID that is not negligible must include
the OID in income for federal income tax purposes as it accrues, in advance of
the receipt of the cash attributable to such income, under a method that takes
into account the compounding of interest.

SALE OR OTHER DISPOSITION OF THE CERTIFICATES

      Upon the sale, exchange or other disposition of a certificate, a U.S.
certificateholder generally will recognize capital gain or loss equal to the
difference between the amount realized on the disposition, other than any amount
attributable to accrued interest which will be taxable as ordinary income, and
the U.S. certificateholder's adjusted tax basis in the related equipment notes
and any other property held by the corresponding pass through trust. Any gain or
loss will be long-term capital gain or loss to the extent attributable to
property held by the pass through trust for more than one year. In the case of
individuals, estates, and trusts, the maximum rate of tax on net long-term
capital gains generally is 20%.


                                       30

FOREIGN CERTIFICATEHOLDERS

      Subject to the discussion of backup withholding below, payments of
principal and interest (including any OID) on the equipment notes to, or on
behalf of, any beneficial owner of a certificate that is not a U.S. person will
not be subject to U.S. federal withholding tax provided that:

      -     the non-U.S. certificateholder does not actually or constructively
own 10% or more of the total combined voting power of all classes of stock of an
owner participant or us;

      -     the non-U.S. certificateholder is not a bank receiving interest
pursuant to a loan agreement entered into in the ordinary course of its trade or
business, or a controlled foreign corporation for U.S. tax purposes that is
related to an owner participant or us; and

      -     certain certification requirements (including identification of the
beneficial owner of the certificate) are complied with.

      Any capital gain realized upon the sale, exchange, retirement or other
disposition of a certificate or upon receipt of premium paid on an equipment
note by a non-U.S. certificateholder will not be subject to U.S. federal income
or withholding taxes if (i) such gain is not effectively connected with a U.S.
trade or business of the non-U.S. certificateholder and (ii) in the case of an
individual, such non-U.S. certificateholder is not present in the United States
for 183 days or more in the taxable year of the sale, exchange, retirement or
other disposition or receipt.

BACKUP WITHHOLDING

      Payments made on the certificates will not be subject to a backup
withholding tax unless, in general, the certificateholder fails to comply with
certain reporting procedures or otherwise fails to establish an exemption from
such tax under applicable provisions of the Code. Currently, the backup
withholding tax rate is 30.5%. Under recent amendments to the Code, this rate
will be reduced to 30% in 2002, to 29% in 2004 and to 28% in 2006 and
thereafter.

                              ERISA CONSIDERATIONS

      Unless otherwise indicated in the applicable prospectus supplement, the
certificates may, subject to certain legal restrictions, be purchased and held
by an employee benefit plan subject to Title I of the Employee Retirement Income
Security Act of 1974, as amended, referred to as "ERISA," or an individual
retirement account or an employee benefit plan subject to section 4975 of the
Code. A fiduciary of an employee benefit plan must determine that the purchase
and holding of a certificate is consistent with its fiduciary duties under ERISA
and does not result in a non-exempt prohibited transaction as defined in section
406 of ERISA or section 4975 of the Code. Employee benefit plans which are
governmental plans, as defined in section 3(32) of ERISA, and certain church
plans, as defined in section 3(33) of ERISA, are not subject to Title I of ERISA
or section 4975 of the Code. The certificates may, subject to certain legal
restrictions, be purchased and held by such plans.


                                       31

                              PLAN OF DISTRIBUTION

      Certificates may be sold to one or more underwriters for public offering
and resale by them. Certificates may also be sold to investors or other persons
directly or through one or more dealers or agents. Any underwriter, dealer or
agent involved in the offer and sale of the certificates will be named in an
applicable prospectus supplement.

      The certificates may be sold:

      -     at a fixed price or prices, which may be changed;

      -     at market prices prevailing at the time of sale;

      -     at prices related to prevailing market prices; or

      -     at negotiated prices.

      Dealer trading may take place in certain of the certificates, including
certificates not listed on any securities exchange. We do not intend to apply
for listing of the certificates on a national securities exchange. From time to
time, we also may authorize underwriters acting as our agents to offer and sell
the certificates upon the terms and conditions as will be set forth in any
prospectus supplement.

      In connection with the sale of certificates, underwriters may be deemed to
have received compensation from us in the form of underwriting discounts or
commissions and may also receive commissions from purchasers of certificates for
whom they may act as agent. Underwriters may sell certificates to or through
dealers, and those dealers may receive compensation in the form of discounts,
concessions or commissions from the underwriters and/or commissions, which may
be changed from time to time, from the purchasers for whom they may act as
agent.

      If a dealer is used directly by us in the sale of certificates in respect
of which this prospectus is delivered, we will sell the certificates to the
dealer, as principal. The dealer may then resell the certificates to the public
at varying prices to be determined by the dealer at the time of resale. The
dealer will be named in, and the terms of the sale, will be set forth in the
applicable prospectus supplement.

      Certificates may be offered and sold through agents designated by us from
time to time. The agent involved in the offer or sale of the certificates will
be named in, and any commissions payable by us to the agent will be set forth
in, the applicable prospectus supplement. Unless otherwise indicated in the
applicable prospectus supplement, the agent will be acting on a best efforts
basis for the period of its appointment.

      We may solicit directly offers to purchase certificates, and certificates
may be sold directly to institutional investors or others who may be deemed to
be underwriters within the meaning of the Securities Act with respect to any
resale. The terms of these sales will be described in the applicable prospectus
supplement. Except as set forth in the applicable prospectus supplement, no
director, officer or employee of ours will solicit or receive a commission in
connection with direct


                                       32

sales by us of the certificates, although those persons may respond to inquiries
by potential purchasers and perform ministerial and clerical work in connection
with our direct sales.

      Any underwriting compensation that we pay to underwriters, dealers or
agents in connection with the offering of certificates, and any discounts,
concessions or commissions allowed by underwriters to participating dealers,
will be set forth in an applicable prospectus supplement.

      Underwriters, dealers and agents participating in the distribution of the
certificates may be deemed to be underwriters, and any discounts and commissions
received by them and any profit realized by them on resale of the certificates
may be deemed to be underwriting discounts and commissions under the Securities
Act. Underwriters, dealers and agents may be entitled under agreements with us
to indemnification against and contribution toward certain civil liabilities,
including liabilities under the Securities Act, and to reimbursement by us for
certain expenses.

      Underwriters, dealers and agents may engage in transactions with, or
perform services for, us and our subsidiaries in the ordinary course of
business.

      If so indicated in an applicable prospectus supplement and subject to
existing market conditions, we will authorize dealers acting as our agents to
solicit offers by certain institutions to purchase certificates from us at the
public offering price set forth in the applicable prospectus supplement pursuant
to delayed delivery contracts. These contracts will provide for payment and
delivery on the date or dates stated in the applicable prospectus supplement.
Each contract will be for an amount not less than, and the aggregate principal
amount of certificates sold pursuant to these contracts will not be less nor
more than, the respective amounts stated in the applicable prospectus
supplement. Institutions with whom these contracts, when authorized, may be made
include commercial and savings banks, insurance companies, pension funds,
investment companies, educational and charitable institutions and other
institutions, but will in all cases be subject to our approval. These contracts
will not be subject to any conditions, except for the condition that the
purchase by an institution of the certificates not be prohibited at the time of
delivery under the laws of any jurisdiction in the United States to which the
institution is subject. A commission set forth in the applicable prospectus
supplement will be granted to underwriters and agents soliciting purchases of
certificates pursuant to contracts accepted by us. Agents and underwriters will
have no responsibility in respect of the delivery or performance of these
contracts.

      If an underwriter or underwriters is used in the sale of any certificates,
the applicable prospectus supplement will state the intention, if any, of the
underwriters at the date of the prospectus supplement to make a market in the
certificates. We cannot assure you that there will be a market for the
certificates.

      The place and time of delivery for the certificates in respect of which
this prospectus is delivered will be set forth in the applicable prospectus
supplement.

                          VALIDITY OF THE CERTIFICATES

      Unless otherwise indicated in the applicable prospectus supplement, the
validity of the offered Certificates will be passed upon for us by Deborah
Ackerman, Vice President -- General


                                       33

Counsel. Ms. Ackerman will rely on the opinion of counsel for Wilmington Trust
Company as to certain matters relating to the authorization, execution and
delivery of the Certificates by and the valid binding effect on the Trustee.

                                     EXPERTS

      Ernst & Young LLP, independent auditors, have audited our consolidated
financial statements included in our Annual Report on Form 10-K for the year
ended December 31, 2000, as set forth in their report, which is incorporated by
reference in this prospectus and elsewhere in the registration statement. Our
consolidated financial statements are incorporated by reference in reliance on
Ernst & Young LLP's report, given on their authority as experts in accounting
and auditing.

                       WHERE YOU CAN FIND MORE INFORMATION

      We file annual, quarterly and special reports, proxy statements and other
information with the SEC. You may read and copy any documents we file at the
SEC's public reference room 450 Fifth Street, N.W., Washington, D.C. 20549.
Please call the SEC at 1-800-SEC-0330 for further information on the public
reference room. Our SEC filings are also available to the public on the SEC's
web site at http://www.sec.gov and through the New York Stock Exchange, 20 Broad
Street, New York, New York 10005, on which our common stock is listed.

      The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be part of this prospectus, and later information that we file
with the SEC will automatically update and supersede this information as well as
the information included in this prospectus. We incorporate by reference the
documents listed below and any future filings made with the SEC under Sections
13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934 ("Exchange
Act") until we sell all the Certificates.

      -     Annual Report on Form 10-K for the fiscal year ended December 31,
2000;

      -     Quarterly Reports on Form 10-Q for the quarters ended March 31 and
June 30, 2001; and

      -     Current Report on Form 8-K dated October 3, 2001.

      Any party to whom this prospectus is delivered, including a holder in
street name, may request a copy of these filings (other than any exhibits unless
specifically incorporated by reference into this prospectus), at no cost, by
writing or telephoning us at the following address:

                             Southwest Airlines Co.
                             Investor Relations
                             P.O. Box 36611, HDQ-6FC
                             2702 Love Field Drive
                             Dallas, Texas 75235
                             (214) 792-4000


                                       34

                                     PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.


                                                                
Securities and Exchange Commission Registration Fee                $  250,000
Trustee's Fees and Expenses                                            50,000
Printing and Engraving Expenses                                       200,000
Rating Agency Fees                                                    200,000
Accountants' Fees and Expenses                                         50,000
Legal Fees and Expenses                                               200,000
Miscellaneous                                                         250,000
                                                                   ----------
             Total                                                 $1,200,000


      All amounts above are estimated except for the registration fee.

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

      Article VIII, Section 1 of Registrant's Bylaws provides as follows:

            "Right to Indemnification: Subject to the limitations and conditions
as provided in this Article VIII, each person, who was or is made a party to, or
is threatened to be made a party to, any threatened, pending or completed
action, suit or proceeding, whether civil, criminal, administrative, arbitrative
or investigative (hereinafter called a "proceeding"), or any appeal in such a
proceeding or any inquiry or investigation that could lead to such a proceeding,
by reason of the fact that he (or a person of whom he is the legal
representative) is or was a director or officer of the corporation (or while a
director or officer of the corporation is or was serving at the request of the
corporation as a director, officer, partner, venturer, proprietor, trustee,
employee, agent, or similar functionary of another foreign or domestic
corporation, partnership, joint venture, proprietorship, trust, employee benefit
plan, or other enterprise) shall be indemnified by the corporation to the
fullest extent permitted by the Texas Business Corporation Act, as the same
exists or may hereafter be amended (but, in the case of any such amendment, only
to the extent that such amendment permits the corporation to provide broader
indemnification rights than said law permitted the corporation to provide prior
to such amendment) against judgments, penalties (including excise and similar
taxes and punitive damages), fines, settlements and reasonable expenses
(including, without limitation, court costs and attorneys' fees) actually
incurred by such person in connection with such proceeding, appeal, inquiry or
investigation, and indemnification under this Article VIII shall continue as to
a person who has ceased to serve in the capacity which initially entitled such
person to indemnity hereunder; provided, however, that in no case shall the
corporation indemnify any such person (or the legal representative of any such
person) otherwise than for his reasonable expenses, in respect of any proceeding
(i) in which such person shall have been finally adjudged by a court of
competent jurisdiction (after exhaustion of all appeals therefrom) to be liable
on the basis that personal benefit was improperly received by him, whether or
not the benefit resulted from an action taken in such person's official
capacity, or (ii) in which such person shall have been found


                                      II-1

liable to the corporation; and provided, further, that the corporation shall not
indemnify any such person for his reasonable expenses actually incurred in
connection with any proceeding in which he shall have been found liable for
willful or intentional misconduct in the performance of his duty to the
corporation. The rights granted pursuant to this Article VIII shall be deemed
contract rights, and no amendment, modification or repeal of this Article VIII
shall have the effect of limiting or denying any such rights with respect to
actions taken or proceedings arising prior to any such amendment, modification
or repeal. It is expressly acknowledged that the indemnification provided in
this Article VIII could involve indemnification for negligence or under theories
of strict liability."

      Article Ten of the Company's Articles of Incorporation provides that a
director of the corporation shall not be liable to the corporation or its
shareholders for monetary damages for an act or omission in the director's
capacity as a director, subject to certain limitations.

      Article 2.02-1B. of the Texas Business Corporation Act provides that,
subject to certain limitations, "a corporation may indemnify a person who was,
is, or is threatened to be made a named defendant or respondent in a proceeding
because the person is or was a director only if it is determined in accordance
with Section F of this article that the person: (1) conducted himself in good
faith; (2) reasonably believed: (a) in the case of conduct in his official
capacity as a director of the corporation, that his conduct was in the
corporation's best interests; and (b) in all other cases, that his conduct was
at least not opposed to the corporation's best interests; and (3) in the case of
any criminal proceeding, had no reasonable cause to believe his conduct was
unlawful."

      The Company also maintains directors' and officers' liability insurance.

      The forms of Underwriting Agreement filed as Exhibits 1.1 and 1.2 to this
Registration Statement provide for indemnification of directors and officers of
the Company against certain liabilities.

ITEM 16. EXHIBITS.

            1.1   Form of Underwriting Agreement for Debt Securities
                  (incorporated by reference to Exhibit 1 to the Company's
                  Registration Statement on Form S-3 (File No. 33-50930)).

            1.2   Form of Underwriting Agreement for Pass Through Certificates
                  (incorporated by reference to Exhibit 1 to the Company's
                  Registration Statement on Form S-3 (File No. 33-59018)).

            4.1   Indenture between the Company and U.S. Trust Company of Texas,
                  N.A., dated February 25, 1997 relating to Debt Securities
                  (incorporated by reference to Exhibit 4.12 to the Company's
                  Annual Report on Form 10-K for the year ended December 31,
                  1996 (File No. 1-7259)).

            4.2   Pass Through Trust Agreement, dated as of October 10, 2001,
                  between Southwest and Wilmington Trust Company.

            5.1   Opinion of Deborah Ackerman, Vice President - General Counsel
                  of Southwest, re legality of Pass Through Certificates being
                  registered.


                                      II-2

            5.2   Opinion of Deborah Ackerman, Vice President - General Counsel
                  of Southwest, re legality of Debt Securities being registered.

            5.3   Opinion of Morris James Hitchens & Williams relating to Pass
                  Through Certificates.

            8     Tax opinion of Vinson & Elkins L.L.P.

            12    Statement re computation of ratios of earnings to fixed
                  charges

            23.1  Consent of Independent Auditors.

            23.2  Consent of Deborah Ackerman, Vice President - General Counsel
                  of Southwest (contained in the opinions filed as Exhibits 5.1
                  and 5.2 hereto respectively).

            23.3  Consent of Morris James Hitchens & Williams (contained in the
                  opinion filed as Exhibit 5.3 hereto).

            25.1  Form T-1 Statement of Eligibility and Qualification under the
                  Trust Indenture Act of 1939 of U.S. Trust Company of Texas,
                  N.A., as Trustee under the Debt Securities.

            25.2  Form T-1 Statement of Eligibility and Qualification under the
                  Trust Indenture Act of 1939 of Wilmington Trust Company, as
                  Trustee under the Pass Through Trust Agreement.

ITEM 17. UNDERTAKINGS.

A.    The undersigned registrant hereby undertakes:

      (1)   To file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement:

            (i)   to include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933;

            (ii)  to reflect in the prospectus any facts or events arising after
the effective date of the registration statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represent a fundamental change in the information set forth in the registration
statement;

            (iii) to include any material information with respect to the plan
of distribution not previously disclosed in the registration statement or any
material change to such information in the registration statement;

provided, however, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed by the registrant pursuant to
Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are
incorporated by reference in the registration statement.

      (2)   That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to


                                      II-3

the securities offered therein, and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof.

      (3)   To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

B.    The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

C.    Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.


                                      II-4

                                   SIGNATURES

      Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned thereunto duly
authorized in the City of Dallas, State of Texas on October 8, 2001.

                                               SOUTHWEST AIRLINES CO.

                                               By /s/ Gary C. Kelly
                                               ----------------------
                                                      Gary C. Kelly
                                                      Chief Financial Officer

      Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on October 8, 2001.



           Signature                                  Capacity
           ---------                                  --------

                                      
/s/ James F. Parker                      Chief Executive Officer and Director
---------------------------------
James F. Parker


/s/ Gary C. Kelly                        Chief Financial Officer
---------------------------------
Gary C. Kelly


/s/ Herbert D. Kelleher                  Chairman of the Board of Directors
---------------------------------
Herbert D. Kelleher


/s/ Colleen C. Barrett                   Director
---------------------------------
Colleen C. Barrett


/s/ Samuel E. Barshop                    Director
---------------------------------
Samuel E. Barshop


/s/ Gene H. Bishop                       Director
---------------------------------
Gene H. Bishop


/s/ C. Webb Crockett                     Director
---------------------------------
C. Webb Crockett


/s/ William H. Cunningham                Director
---------------------------------
William H. Cunningham, Ph.D.


/s/ William P. Hobby                     Director
---------------------------------
William P. Hobby



                                       1


                                      
/s/ Travis C. Johnson                    Director
---------------------------------
Travis C. Johnson

/s/ R. W. King                           Director
---------------------------------
R. W. King

/s/ June M. Morris                       Director
---------------------------------
June M. Morris



                                       2

                                INDEX TO EXHIBITS

      1.1   Form of Underwriting Agreement for Debt Securities (incorporated by
            reference to Exhibit 1 to the Company's Registration Statement on
            Form S-3 (File No. 33-50930)).

      1.2   Form of Underwriting Agreement for Pass Through Certificates
            (incorporated by reference to Exhibit 1 to the Company's
            Registration Statement on Form S-3 (File No. 33-59018)).

      4.1   Indenture between the Company and U.S. Trust Company of Texas, N.A.,
            dated February 25, 1997 relating to Debt Securities (incorporated by
            reference to Exhibit 4.12 to the Company's Annual Report on Form
            10-K for the year ended December 31, 1996 (File No. 1-7259)).

      4.2   Pass Through Trust Agreement, dated as of October 10, 2001,
            between Southwest and Wilmington Trust Company.

      5.1   Opinion of Deborah Ackerman, Vice President - General Counsel of
            Southwest, re legality of Pass Through Certificates being
            registered.

      5.2   Opinion of Deborah Ackerman, Vice President - General Counsel of
            Southwest, re legality of Debt Securities being registered.

      5.3   Opinion of Morris James Hitchens & Williams relating to Pass Through
            Certificates.

      8     Tax opinion of Vinson & Elkins L.L.P.

      12    Statement re computation of ratios of earnings to fixed charges

      23.1  Consent of Independent Auditors.

      23.2  Consent of Deborah Ackerman, Vice President - General Counsel of
            Southwest (contained in the opinions filed as Exhibits 5.1 and 5.2
            hereto respectively).

      23.3  Consent of Morris James Hitchens & Williams (contained in the
            opinion filed as Exhibit 5.3 hereto).

      25.1  Form T-1 Statement of Eligibility and Qualification under the Trust
            Indenture Act of 1939 of U.S. Trust Company of Texas, N.A., as
            Trustee under the Debt Securities.

      25.2  Form T-1 Statement of Eligibility and Qualification under the Trust
            Indenture Act of 1939 of Wilmington Trust Company, as Trustee under
            the Pass Through Trust Agreement.


                                       i