and American Trans Air, Inc. Supplemental Exhibit CS1 to Purchase Agreement Number 2285 CUSTOMER SUPPORT VARIABLES

                           CUSTOMER SUPPORT VARIABLES

                                     between

                               THE BOEING COMPANY

                                       and

                            American Trans Air, Inc.


                   Supplemental Exhibit CS1 to Purchase Agreement Number 2285







                           CUSTOMER SUPPORT VARIABLES

                                   relating to

                          BOEING MODEL 757-33N AIRCRAFT


Customer currently operates an aircraft of the same model as the Aircraft.  Upon
Customer's  request,  Boeing will  develop and  schedule a  customized  Customer
Support  Program to be  furnished  in support of the  Aircraft.  The  customized
program will be based upon and equivalent to the entitlements summarized below.

1.       MAINTENANCE TRAINING.
         --------------------

         1.1      Maintenance   Training  Minor  Model  Differences  Course,  if
                  required,   covering   operational,   structural   or  systems
                  differences between Customer's newly-purchased Aircraft and an
                  aircraft of the same model currently  operated by Customer;  1
                  class of 15 students;

         1.2      Training  materials,  if applicable,  will be provided to each
                  student. In addition, one set of training materials as used in
                  Boeing's  training  program,  including  visual aids, text and
                  graphics will be provided for use in  Customer's  own training
                  program.

2.       FLIGHT TRAINING.
         ---------------

         Boeing will provide,  if required,  one classroom course to acquaint up
         to 15 students with  operational,  systems and performance  differences
         between Customer's newly-purchased Aircraft and an aircraft of the same
         model currently operated by Customer.

         Any training  materials used in Flight Training,  if required,  will be
         provided for use in Customer's own training program.

3.       PLANNING ASSISTANCE.
         -------------------

         3.1      MAINTENANCE AND GROUND OPERATIONS.
                  ---------------------------------

                  Upon  request,   Boeing  will  provide   planning   assistance
                  regarding Minor Model Differences requirements for facilities,
                  tools and equipment.

         3.2      SPARES.
                  ------

                  Boeing will revise, as applicable,  the customized Recommended
                  Spares Parts List (RSPL) and Illustrated Parts Catalog (IPC).

4.       TECHNICAL DATA AND DOCUMENTS.
         ----------------------------

         Boeing  will  revise,  as  applicable,  technical  data  and  documents
         provided with previously delivered aircraft.