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                                                                     EXHIBIT 5.1

                                  [LETTERHEAD]
                           CRAVATH, SWAINE & MOORE LLP

                                                                     May 3, 2004

                               ATA HOLDINGS CORP.
                             SENIOR NOTES DUE 2009
                             SENIOR NOTES DUE 2010
                        FORM S-4 REGISTRATION STATEMENT

Ladies and Gentlemen:

    We have acted as counsel for ATA Holdings Corp., an Indiana Corporation (the
'Company'), ATA Airlines, Inc., Ambassadair Travel Club, Inc., ATA Leisure
Corp., Amber Travel, Inc., American Trans Air Training Corporation, American
Trans Air Execujet, Inc. each, an Indiana corporation, ATA Cargo, Inc., a
California corporation, and Chicago Express Airlines, Inc., a Georgia
corporation (together with the Company, the 'Registrants'), in connection with
the filing by the Registrants with the Securities and Exchange Commission (the
'Commission') of a registration statement on Form S-4 (the 'Registration
Statement') under the Securities Act of 1933, as amended (the 'Act'), relating
to the proposed issuance and exchange of up to $163,064,000 aggregate principal
amount of the Company's outstanding Senior Notes due 2009 (the '2009 Private
Exchange Notes') for a like principal amount of the Company's registered Senior
Notes due 2009 (the '2009 Registered Notes') and $110,233,000 aggregate
principal amount of the Company's outstanding Senior Notes due 2010 (the '2010
Private Exchange Notes') for a like principal amount of the Company's registered
Senior Notes due 2010 (the '2010 Registered Notes'). The 2009 Registered Notes
are to be issued pursuant to an indenture dated as of January 30, 2004 (the
'2009 Notes Indenture'), among the Registrants and Wells Fargo Bank Northwest,
National Association ('Wells Fargo'), as trustee. The 2010 Registered Notes are
to be issued pursuant to an indenture dated as of January 30, 2004 (the '2010
Notes Indenture' and, together with the 2009 Notes Indenture, the 'Indentures'),
among the Registrants and Wells Fargo, as trustee.

    In that connection, we have examined originals, or copies certified or
otherwise identified to our satisfaction, of such documents, corporate records
and other instruments as we have deemed necessary or appropriate for purposes of
this opinion, including the Indenture.

    Based on the foregoing, we are of opinion as follows:

    1. Assuming that each of the Indentures has been duly authorized, executed
and delivered by the Registrants, each of the Indentures constitutes a legal,
valid and binding obligation of the Registrants, enforceable against the
Registrants in accordance with its terms (subject to applicable bankruptcy,
insolvency, reorganization, moratorium, fraudulent transfer or other similar
laws affecting creditors' rights generally from time to time in effect and to
general principles of equity, including concepts of materiality, reasonableness,
good faith and fair dealing, regardless of whether such enforceability is
considered in a proceeding in equity or at law).

    2. Each of (i) the 2009 Registered Notes, when executed, issued and
authenticated in accordance with the provisions of the 2009 Notes Indenture and
delivered in exchange for the 2009 Private Exchange Notes, and (ii) the
Registered 2010 Notes, when executed, issued and authenticated in accordance
with the provisions of the 2010 Notes Indenture, and delivered in exchange for
the 2010 Private Exchange Notes, will constitute legal, valid and binding
obligations

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of the Registrants, enforceable against the Registrants in accordance with their
terms and entitled to the benefits of their respective Indenture (subject to
applicable bankruptcy, insolvency, fraudulent transfer, reorganization,
moratorium or other similar laws affecting creditors' rights generally from time
to time in effect and subject, as to enforceability, to general principles of
equity, regardless of whether such enforceability is considered in a proceeding
in equity or at law). In expressing the opinion set forth in this paragraph 2,
we have assumed that the form of the 2009 Registered Notes will conform to the
form included in the 2009 Notes Indenture and that the form of the 2010
Registered Notes will conform to the form included in the 2010 Notes Indenture.

    We hereby consent to the filing of this opinion with the Commission as
Exhibit 5.1 to the Registration Statement. We also consent to the reference to
our firm under the caption 'Legal Matters' in the Registration Statement. In
giving this consent, we do not thereby admit that we are included in the
category of persons whose consent is required under Section 7 of the Act or the
rules and regulations of the Commission.

    We are admitted to practice in the State of New York and we do not express
any opinion with respect to matters governed by any laws other than the laws of
the State of New York, the General Corporation Law of the State of Delaware and
the federal laws of the United States of America.

                                          Very truly yours,

                                          /s/ Cravath, Swaine & Moore LLP

ATA HOLDINGS CORP.
ATA AIRLINES, INC.
AMBASSADAIR TRAVEL CLUB, INC.
ATA LEISURE CORP.
AMBER TRAVEL, INC.
AMERICAN TRANS AIR TRAINING
CORPORATION
AMERICAN TRANS AIR EXECUJET, INC.
ATA CARGO, INC.
CHICAGO EXPRESS AIRLINES INC.
7337 West Washington Street
Indianapolis, Indiana 46231






























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