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                                                                   Exhibit 10.57

                            LETTER AGREEMENT (N375SK)

      LETTER AGREEMENT (N375SK), dated as of February 20, 2002, among Solitair
Corp. ("SOLITAIR"), Chautauqua Airlines, Inc. (the "AIRLINE" or "BORROWER") and
Embraer-Empresa Brasileira de Aeronautica S.A. ("EMBRAER").

      Solitair has agreed to purchase from Embraer new EMB-145 model EMB-135 KL
aircraft (the "Purchase Agreement AIRCRAFT") pursuant to the Purchase Agreement
Number GCT-025/98 dated June 17, 1998, as amended (the "PURCHASE AGREEMENT").
Solitair is assigning its right to purchase one of the Purchase Agreement
Aircraft, bearing msn 145569 (the "AIRCRAFT") to the Airline on the date hereof,
and Embraer has agreed to provide interim financing to the Airline for its
purchase of such Aircraft, subject to certain agreements of the parties hereto.
Terms defined in the Loan Agreement and used herein have such defined meanings
unless otherwise defined herein. Accordingly, the parties hereto agree as
follows:

      1. LOAN. (a) On the date hereof, Embraer is financing 90% of the "Aircraft
Purchase Price" (as defined in the Purchase Agreement) for the Aircraft by
making a loan (the "LOAN") to the Airline pursuant to an Interim Loan Agreement
(N375SK) between the Borrower and Embraer dated as of the date hereof (the "Loan
Agreement").

      (b) Embraer and the Airline hereby agree that for purposes of determining
the monthly payment amount during the Term (as defined in the Loan Agreement),
the amount of the Loan shall be reduced by $150,000 for the "Debt Commitment"
and by $349,489.28 for the "Special Credit Rebate" (each as defined in Amendment
No. 1 to Letter Agreement GCT 026/98).

      2. COOPERATION. (a) During the Term (as defined in the Loan Agreement),
the Airline, Solitair and Embraer shall reasonably cooperate and update each
other on the ongoing negotiations among the Airline and FINAME and American
Airlines, Inc. (and, if applicable, its affiliates) ("American"), for the FINAME
Refinancing (as defined in Section 4 below).

            (b) Solitair and the Airline agree that upon the execution of FINAME
Refinancing documentation applicable to EMB-135KL aircraft to be operated
pursuant to a code-share agreement with American, the Aircraft shall, after the
three other EMB-135KL aircraft delivered by Embraer to the Airline on December
31, 2001, be the first aircraft to be financed pursuant to such FINAME
Refinancing, with 80% of the Aircraft Purchase Price to be credited directly by
FINAME to Embraer and 10% (the "Down Payment") to be paid to Embraer by the
Airline; provided that at the time of such FINAME Refinancing, Embraer shall
provide or cause to be provided to the Airline a loan for the remaining 10% of
the Aircraft Purchase Price at a rate of 9% per annum for a loan term of 2
years, with other terms to be reasonably agreed by the Airline and Embraer or
its designee.

            (c) The Airline covenants and agrees that it shall make good faith
efforts with FINAME, and reasonable efforts with American and Embraer, to
complete the FINAME Refinancing.

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            (d) In the event the Airline repays the Loan other than through a
FINAME Refinancing, the Proex notes with respect to the Aircraft shall be
promptly discounted pursuant to Section 5(a) and all proceeds of such
discounting shall be paid directly to Embraer and immediately paid by Embraer to
the Airline.

            (e) (i) Embraer agrees that notwithstanding anything to the contrary
in the Loan Agreement (including without limitation Section 9.4 thereof),
provided that no Event of Default has occurred and is continuing, it will not
assign or transfer any of its rights or obligations thereunder until the
discounting of the Proex notes and payment of the proceeds thereof as referred
to above, except in connection with a FINAME Refinancing.

                  (ii) The Airline agrees that notwithstanding anything to the
contrary in the Loan Agreement, before any discounting of the Proex notes and
payment of the proceeds thereof as referred to above, the rights provided in
Section 7.2 of the Loan Agreement shall not apply.

      3. CREDIT SUPPORT. In the event the Airline seeks to refinance the Loan
other than through a FINAME Refinancing, the Airline shall have the right to
obtain a residual value guarantee and/or a first loss deficiency guarantee to
support its refinancing of the Aircraft ("Credit Support") with investors other
than FINAME, on terms and at prices previously agreed by Solitair and Embraer,
for a refinancing to occur on or before the Maturity Date. The Airline may apply
the $150,000 amount referred to in Section 1.b hereof to the price of any such
support, and any additional amounts due will increase the purchase price of
future deliveries of aircraft under the Purchase Agreement as agreed between
Solitair and Embraer if there are undelivered firm order aircraft at that time,
but otherwise shall be paid by the Airline to Embraer. If the Loan is
refinanced, other than by FINAME, without using Credit Support, the principal
amount of the Loan shall be deemed cancelled and satisfied in the amount of
$150,000.

      4. FINAME REFINANCING. If the Airline refinances the Aircraft (a "FINAME
Refinancing") with a borrowing from Agencia Especial de Financiamento Industrial
("FINAME"), the Loan shall be repaid in the principal amount of the loan made by
FINAME in such refinancing upon the closing of such refinancing, although
Embraer shall accept funds from FINAME in the Brazilian currency in satisfaction
of such Loan. If the principal amount of the loan made by FINAME in such
refinancing as aforesaid exceeds the outstanding principal amount of the Loan on
such closing date Embraer shall refund to the Airline on such closing date an
amount equal to such excess. Upon such refinancing by FINAME, Embraer shall
return for cancellation the promissory note issued by the Airline to Embraer.

      5. PROEX BENEFITS. Embraer represents and warrants to the Airline that,
provided that no Event of Default (as defined in the Loan Agreement) shall have
occurred and be continuing, the Airline will be entitled to the Proex Benefits
as described in Article 1B of Amendment Number 1 to Letter Agreement GCT-026/98,
between Embraer and Solitair (the "PROEX BENEFITS") with respect to the Aircraft
as if the Proex Benefits were made available to the Airline on the date hereof
for such Aircraft.

            (a) In the event the Airline repays the Loan other than through a
FINAME Refinancing, the parties shall take all necessary measures to ensure that
Citibank - Brazil (acting as the "Proex Agent Bank") will promptly discount the
Proex notes which are otherwise due on

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semi-annual basis until the 15th year following the Aircraft Delivery Date,
which value shall be determined using the same methodology and assumptions as
used by the Proex Agent Bank in its previous purchases between itself and
Imprimis Investors LLC ("IMPRIMIS"). If the cash value obtained by the Airline
by the discounting of Proex under this Section 5(a) is less than the cash value
which would have been obtained by the Airline by the discounting of Proex in a
similar manner to that which has been obtained by Imprimis using the same
methodology and assumptions as used by Citibank-Brazil and Embraer in its
previous purchases of Proex notes from Imprimis, as adjusted for the then
current five-year LIBOR swap rate, then Embraer shall immediately pay such
difference to the Airline.

            (b) If on any refinancing of the Aircraft utilizing a loan from
FINAME, the interest rate proposed by FINAME applicable to the debt service
payments on such loan would otherwise exceed the interest rate that would have
been provided by FINAME, which rate is the Commercial Interest Reference Rate in
effect at the time of closing for U.S. dollar loans with more than 17
semi-annual repayment periods, exclusively due to a reduction in the value of
the Proex Benefits, then at the time of such refinancing Embraer shall
compensate FINAME with the necessary amount to adjust the FINAME loan to
preserve the same economics for the Airline.

      6. SPECIAL CREDIT REBATE. On the day that Embraer receives payment in full
under the Promissory Note dated the date hereof with respect to the Aircraft,
Embraer shall pay the Airline the Special Credit Rebate in the amount of
$349,489.28; provided that if the Airline and Embraer agree otherwise, Embraer
may pay such amount after the day that Embraer receives payment.

      7. INSURANCE. If any lease agreement under which Airline leases an Embraer
aircraft from General Electric Company or any of its Affiliates is amended or
modified to reduce the war risk and allied perils insurance required to be
maintained by Airline with respect to such aircraft below the requirements of
the Security Agreement, upon request of the Airline Embraer shall amend the
Security Agreement to require such insurance at the reduced level.

      8. AMERICAN AIRLINES CODE SHARE, END-OF TERM PUT OPTION. (a) The Airline
hereby confirms that by means of a modification to the Air Services Agreement
dated June 11, 2001 (the "Air Services Agreement") between the Airline and AMR
Corporation ("AMR"), the Airline and AMR have agreed that the Airline may
operate the Aircraft for up to the duration of the Term regardless of whether
the terms of the Loan Agreement and related documents satisfy the requirements
of the Air Services Agreement.

            (b) If (i) the Airline and (at Embraer's option) Embraer, are unable
to implement a refinancing of the Aircraft before the end of the 75th day prior
to the Maturity Date, on terms as favorable to the Airline as the FINAME
financing terms planned to be consummated on December 28, 2001 (except that the
FINAME Refinancing shall a financing be for 80% of the Aircraft Purchase Price)
and on terms as shall have been approved by AMR, and no Event of Default
referred to in Section 8.1(a)(i) of the Loan Agreement shall have occurred and
be continuing, then notwithstanding the terms of the Loan Agreement and the
Promissory Note, the Airline shall have the option to put the Aircraft to
Embraer at the end of the Term, on the terms provided in Section 8(c) below,
unless the parties have agreed in writing otherwise or (ii) an Event of Default
under the Loan Agreement shall have occurred and is continuing (other than an

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Event of Default referred to in Section 8.1(a)(i) of the Loan Agreement) and the
principal amount of the Loan shall have been accelerated, the Airline shall have
the option to put the Aircraft to Embraer on ten Business Days' written notice
to Embraer, on the terms provided in Section 8(c) below (other than clauses (i)
and (iv) thereof). If the Airline does not elect to put the Aircraft to Embraer
as required by this Section 8, then it shall be deemed to have waived the put
option.

            (c) The terms of the put shall be as follows: (i) the Airline shall
provide written notice to Embraer of its exercise of the put option no less than
60 days before the end of the Term; (ii) the Airline shall tender the Aircraft
to Embraer or its designee by delivering the same at an airport designated by
Embraer and approved by the Airline (such approval not to be unreasonably
withheld) in the 48 contiguous states of the United States of America on the
Airline's route system; (iii) the Airline shall deliver a warranty bill of sale
and FAA bill of sale conveying good and marketable title to the Aircraft, free
and clear of all Liens other than Liens attributable to Embraer; (iv) the date
for delivery to Embraer or its designee shall be within ten (10) days after the
last day of the Term; (v) the Airline shall assign all remaining warranties with
respect to the Aircraft (to the extent assignable); and (vi) the Airline (and
Solitair, if applicable) shall assign any rights with respect to Proex to
Embraer or its designee. Upon tender by the Airline to Embraer or its designee
as aforesaid, Embraer shall purchase the Aircraft for an amount equal to the
outstanding principal and unpaid interest under the Promissory Note (the "Unpaid
Balance") (to be paid by cancellation of the Promissory Note in the amount of
the Unpaid Balance) plus the Down Payment, reduced by any amounts due to Embraer
pursuant to Exhibit 1 hereto and, in the event of a put pursuant to Section
8(b)(ii), further reduced by all principal that would otherwise have been due
during the remainder of the Term and any other liquidated amounts due pursuant
to the Loan Agreement and Security Agreement (but excluding any other principal
and interest); provided that if such amounts owed by the Airline exceed the
amount of the Down Payment, the Airline shall pay the excess to Embraer at that
time. For the avoidance of doubt, Embraer shall not owe the Special Credit
Rebate or any amounts related to Proex if Buyer exercises its put option, and
the failure of Buyer to satisfy any provision of Exhibit 1 hereto shall not
invalidate Buyer's right to put the Aircraft to Embraer and Embraer's obligation
to purchase it..

      9. ARBITRATION. The provisions of Sections 21 and 22 of the Purchase
Agreement are incorporated herein by reference and made part of this Letter
Agreement as if set forth herein in full.

      10. GOVERNING LAW. This Letter Agreement shall be governed by the laws of
the State of New York applicable to contracts made and to be performed in such
State.

      11. EFFECT UPON PURCHASE AGREEMENT. A breach of this Letter Agreement by
any party hereto shall not be deemed a breach of the Purchase Agreement by that
party.

      12. THIS AGREEMENT GOVERNS. To the extent of any inconsistency between any
Borrower Loan Document and this Letter Agreement, the Letter Agreement shall
govern.

                       [Remainder of this page is blank.]

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IN WITNESS WHEREOF, the parties hereto, by their duly authorized officers, have
entered into and executed this Letter Agreement to be effective as of the date
first written above.

EMBRAER-Empresa Brasileira
de Aeronautica, S.A.                SOLITAIR CORP.

By:  _______________________        By: _______________________________

Name:  _____________________        Name:  ____________________________

Title:  ____________________        Title: ____________________________

Date:  _____________________        Date: _____________________________


                                    CHAUTAUQUA AIRLINES, INC.

By:  _______________________        By:  ______________________________

Name:_______________________        Name:  ____________________________

Title:______________________        Title: ____________________________

Date:_______________________        Date:  ____________________________


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NOTE TO EXHIBIT 10.57

The three additional Letter Agreements are substantially identical in all
material respects to the filed Letter Agreement except as follows:

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<Caption>

- ------------------------------------- ----------------------------------- -----------------------------------
            TAIL NUMBER                          CLOSING DATE                     OWNER-PARTICIPANT

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              N372SK                           December, 2001                          Embraer
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              N373SK                           December, 2001                          Embraer
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              N374SK                           December, 2001                          Embraer
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</Table>