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                                                                 Exhibit 10.23a

                         LEASE SUPPLEMENT NO. 1 [N281SK]

          THIS LEASE SUPPLEMENT NO. 1 [N281SK] dated February 23, 2001, between
FIRST SECURITY BANK, NATIONAL ASSOCIATION, not in its individual capacity, but
solely as Owner Trustee, except as otherwise provided herein, the Lessor, and
CHAUTAUQUA AIRLINES, INC., a New York corporation, the Lessee;

                              W I T N E S S E T H :

          WHEREAS, the Lessor and the Lessee have heretofore entered into that
certain Lease Agreement [N281SK], dated as of February 23, 2001 (the "Lease",
the terms defined therein being herein used with the same meaning), which Lease
provides, among other things, for the execution and delivery of Lease
Supplements in substantially the form hereof for the purpose of leasing a
specific Aircraft under the Lease when delivered by the Lessor to the Lessee in
accordance with the terms thereof;

          WHEREAS, the Lease, a counterpart of which is attached hereto and made
a part hereof, relates to the Aircraft and Engines described in Schedule I
hereto and this Lease Supplement, together with such attachment, is being filed
for recordation on the date hereof with the FAA as one document;

          NOW, THEREFORE, in consideration of the premises and other good and
sufficient consideration, and pursuant to Section 2 of the Lease, the Lessor and
the Lessee hereby agree as follows:

          1. The Lessor hereby delivers and leases to the Lessee, and the Lessee
hereby accepts and leases from the Lessor, under the Lease as herein
supplemented, the Aircraft, described in Schedule I hereto.

          2. The Delivery Date is the date of this Lease Supplement set forth in
the opening paragraph hereof.

          3. The Basic Term shall commence on the Delivery Date and continue
through August 23, 2017 (the "Expiration Date"), unless terminated earlier as
provided in the Lease.

          4. Lessee hereby confirms to Lessor that Lessee has duly and
irrevocably accepted the Aircraft under and for all purposes hereof, of the
Lease and of the other Lessee Documents.

          5. All of the terms and provisions of the Lease are hereby
incorporated by reference in this Lease Supplement to the same extent as if
fully set forth herein.

          6. This Lease Supplement may be executed by the parties hereto in
separate counterparts and all such counterparts shall together constitute but
one and the same instrument.

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To the extent, if any, that this Lease Supplement constitutes chattel paper (as
such term is defined in the Uniform Commercial Code as in effect in any
applicable jurisdiction), no security interest in this Lease Supplement or the
Lease may be created through the transfer or possession of any counterpart other
than the original counterpart of each thereof marked Counterpart No. 1.

          7. THIS LEASE SUPPLEMENT HAS BEEN DELIVERED IN THE STATE OF NEW YORK
AND SHALL IN ALL RESPECTS BE GOVERNED BY THE LAW OF THE STATE OF NEW YORK,
INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

            [The remainder of this page is intentionally left blank.]

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          IN WITNESS WHEREOF, the Lessor and the Lessee have each caused this
Lease Supplement to be duly executed by their authorized officers as of the day
and year first above written.

                                             FIRST SECURITY BANK,
                                             NATIONAL ASSOCIATION
                                             not in its individual capacity, but
                                             solely as Owner Trustee

                                             By:  /s/ Greg A. Hawley
                                                 -------------------------------
                                                 Name:  Greg A. Hawley
                                                 Title: Vice President

                                             CHAUTAUQUA AIRLINES, INC.

                                             By:  /s/ Robert H. Cooper
                                                 -------------------------------
                                                 Name:  Robert H. Cooper
                                                 Title: Vice President

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                                                                      SCHEDULE I
                                                             TO LEASE SUPPLEMENT

                       DESCRIPTION OF AIRFRAME AND ENGINES

                                    AIRFRAME
<Table>
<Caption>
Manufacturer        Manufacturer's    FAA Registration        Manufacturer's
                        Model              Number               Serial no.
                                                      
Embraer             EMB-145LR          N281SK                  145391
</Table>

                                     ENGINES

<Table>
<Caption>
Manufacturer                        Manufacturer's              Manufacturer's
                                        Model                     Serial No.
                                                          
Allison Engine Company, Inc.        AE 3007A1P                  CAE 311697
                                                                CAE 311698
</Table>

          Each Engine is of 750 or more "rated take-off horsepower" or the
equivalent of such horsepower.


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NOTE TO EXHIBIT 10.23(a)

The 15 additional Lease Supplements No. 1 are substantially identical in all
material respects to the filed Lease Supplement No. 1 except as follows:

<Table>
<Caption>

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

- ------------------------------------- ----------------------------------- -----------------------------------
                                                                    
             N265SK                           June, 2000                  General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N267SK                           June, 2000                  General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N268SK                           June, 2000                  General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N269SK                           August, 2000                General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N270SK                           August, 2000                General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N271SK                           September, 2000             General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N272SK                           September, 2000             General Electric Capital Corporation
- ------------------------------------- ----------------------------------- -----------------------------------
             N273SK                           November, 2000              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N274SK                           December, 2000              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N275SK                           December, 2000              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N276SK                           December, 2000              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N277SK                           December, 2000              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N278SK                           February, 2001              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N279SK                           January, 2001               Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------
             N280SK                           February, 2001              Aircraft Services Corp.
- ------------------------------------- ----------------------------------- -----------------------------------

- ------------------------------------- ----------------------------------- -----------------------------------

- ------------------------------------- ----------------------------------- -----------------------------------
</Table>