American Trans Air, Inc.
7337 West Washington St.
Indianapolis International Airport
Indianapolis, Indiana  46231


     Subject: Spares Initial Provisioning

     Reference:  Purchase  Agreement 2262 (the Purchase  Agreement)  between The
Boeing  Company  (Boeing) and American  Trans Air, Inc.  (Customer)  relating to
Model 737-83N aircraft (the Aircraft)


This  Letter  Agreement  is  entered  into on the date  below,  and  amends  and
supplements  the  Purchase  Agreement.  All terms  used but not  defined in this
Letter Agreement have the same meaning as in the Purchase Agreement.


1.           Applicability.
             -------------

             This  letter  will  apply to  initial  provisioning  for the  Model
737-83N Aircraft purchased by Customer under the Purchase Agreement.


2.           Initial Provisioning Meeting.
             ----------------------------

             Boeing  will  conduct  an  initial  provisioning  meeting  (Initial
Provisioning  Meeting) with Customer to establish mutually agreeable  procedures
to accomplish  Customer's initial  provisioning of spare parts for the Aircraft.
The  parties  will  agree,  during  the  Initial  Provisioning  Meeting  on  the
operational  data to be provided by Customer for  Boeing's use in preparing  its
quantity  recommendations  for  initial  provisioning  of  spare  parts  for the
Aircraft,  exclusive of special  tools,  ground support  equipment,  engines and
engine  parts  (Provisioning  Items).  Such  operational  data to be provided by
Customer  will be the data  described  in Chapter 6 of Boeing  Manual  D6-81834,
entitled  "Spares  Provisioning  Products  Guide"  (Boeing  Spares  Provisioning
Products  Guide)  which  will be  furnished  to  Customer  prior to the  Initial
Provisioning   Meeting.   The  parties  will  also  agree  on  the  provisioning
documentation   to  be  provided  by  Boeing  as  described  in  Boeing   Spares
Provisioning   Products  Guide  (such  data  will  be  hereinafter  referred  to
collectively as the "Provisioning Data"). Boeing will provide instruction in the
use of the initial provisioning documentation. This instruction will be provided
in conjunction with the Initial Provisioning  Meeting. In addition,  the parties
will  discuss  spares  ordering  procedures  and other  matters  related  to the
provisioning  for  the  Aircraft.   The  time  and  location  for  such  Initial
Provisioning Meeting will be mutually agreed upon between the parties;  however,
Boeing and Customer  will use their best efforts to convene such meeting  within
30 days after execution of the Purchase Agreement.


3.           Initial Provisioning Documentation.
             ----------------------------------

             3.1 Provisioning  Data.  Boeing will furnish  Provisioning  Data to
Customer on or about August 25, 2000. The Provisioning  Data will be as complete
as possible and will cover  Provisioning  Items selected by Boeing for review by
Customer for initial  provisioning for the Aircraft.  The Provisioning Data will
set forth the prices for  Provisioning  Items  which are Boeing  Spare Parts and
such prices will be firm and remain in effect  until the date or dates set forth
below in Paragraph 4.1,  Boeing Spare Parts, by which orders must be placed with
Boeing.  Boeing  will,  from time to time,  until a date  approximately  90 days
following  delivery of the last Aircraft or until the delivery  configuration of
each of the Aircraft is reflected in the Provisioning Data,  whichever is later,
furnish to Customer revisions to the Provisioning Data.

             3.2  Provisioning  IPC.  Boeing will,  on or about August 18, 2000,
furnish to  Customer  a Boeing  Illustrated  Parts  Catalog  (IPC),  hereinafter
referred to as the "Provisioning  IPC". The Provisioning IPC will be as complete
as possible and will cover  Provisioning  Items selected by Boeing for review by
Customer for initial  provisioning  for the Aircraft.  Boeing will, from time to
time,  until  a date  approximately  90  days  following  delivery  of the  last
Aircraft,  or  until  the  delivery  configuration  of each of the  Aircraft  is
reflected  in the  Provisioning  IPC,  whichever  is later,  furnish to Customer
revisions to the Provisioning IPC.

             3.3         Buyer Furnished Equipment (BFE) Provisioning Data.
                         -------------------------------------------------

     3.3.1  Boeing's  Responsibility.  Boeing will  include BFE end items in the
Provisioning Data and Provisioning IPC for BFE installed on Customer's  Aircraft
provided  such  equipment  has been  installed  on other  Aircraft by Boeing and
Boeing has data on the BFE.

     3.3.2 Customer's Responsibility.  Customer will be responsible for ensuring
BFE data is provided to Boeing by the BFE  supplier  in a format  acceptable  to
Boeing for BFE not covered by 3.3.1 above. If the data is not provided to Boeing
in a timely manner and in a format acceptable to Boeing, such BFE equipment will
not be included in Boeing's Provisioning Data or IPC.

     3.4  Other  Data.   Boeing   will  submit  to  Customer   listings  of  Raw
Materials,Standard  Parts  and  Bulk  Materials  to be used by  Customer  in the
maintenance and repair of the Aircraft.


     4.  Purchase  from  Boeing of Spare Parts as Initial  Provisioning  for the
Aircraft.

     4.1 Boeing Spare Parts.  Customer will place orders for Provisioning  Items
by November 17, 2000;  provided,  however,  that in those instances where Boeing
submits any revision to the  Provisioning  Data,  Customer will place orders for
Boeing Spare Parts covered by such revision within 60 days following the date of
such  submittal.   At  Customer's  request,   Boeing  will  process  "controlled
shipments"  by  shipping  full or partial  quantities  of an order on a schedule
specified  by  Customer,  provided  the final  shipment is made no later than 24
months after receipt of the order.

     4.2 Supplier  Provisioning Items. Customer may place orders with Boeing for
Provisioning  Items which are  manufactured  by suppliers  or to their  detailed
design and are covered by the Provisioning Data as initial  provisioning for the
Aircraft.  The price to Customer for any such supplier Provisioning Item will be
112% of the supplier's  quoted price to Boeing  therefor.  If Customer elects to
purchase such supplier  Provisioning Items from Boeing,  Customer will place its
orders therefor in accordance with the provisions of Paragraph 4.1, Boeing Spare
Parts.

     4.3 Ground Support  Equipment and Special Tools.  Customer may place orders
with Boeing for ground support equipment (GSE) and special tools manufactured by
suppliers which Customer  determines it will initially  require for maintenance,
overhaul and servicing of the Aircraft and/or engines. The price to Customer for
such GSE or  special  tools will be one  hundred  twelve  percent  (112%) of the
supplier's quoted price to Boeing therefor.  If Customer elects to purchase such
GSE and special tools from Boeing,  Customer  will place its orders  therefor by
the date set forth in  Paragraph  4.1,  Boeing Spare Parts or such later date as
the parties may mutually agree.

     4.4 Spare  Engines and Engine Spare  Parts.  Customer may place orders with
Boeing for spare engines and/or engine spare parts which Customer  determines it
will  initially  require for  support of the  Aircraft  or for  maintenance  and
overhaul of the engines.  The price to Customer  for such spare  engines or such
engine spare parts,  will be 105% of the engine  manufacturer's  quoted price to
Boeing for the engine,  and 112% of the engine  manufacturer's  quoted  price to
Boeing for the engine spare  parts.  If Customer  elects to purchase  such spare
engines or engine spare parts through Boeing,  Customer will place its orders on
a date to be mutually agreed upon during the Initial Provisioning Meeting.

     4.5 QEC Kits. Boeing will, on or about June 30, 2000, furnish to Customer a
listing of all  components  which could be included in the Quick  Engine  Change
(QEC) kits which may be purchased by Customer  from Boeing.  Customer  agrees to
review such listing and  indicate by marking on one copy of such  listing  those
components that Customer desires included in its QEC kits.  Customer will return
such  marked  copy to Boeing  within 30 days  after  Customer's  receipt of such
listing.  Within 30 days after Boeing's receipt of such marked copy, Boeing will
republish such listing to reflect only those components selected by Customer and
will provide copies of such  republished  listing to Customer.  Boeing will from
time  to  time  furnish  revisions  to  such  republished  listing  until a date
approximately 90 days after delivery of the last QEC kit ordered by Customer for
the Aircraft. Boeing will furnish to Customer as soon as practicable a statement
setting forth a firm price for the QEC kit  configuration  selected by Customer.
Customer agrees to place orders with Boeing for the QEC kits for the Aircraft by
August 25, 2000.

     4.6 Payment for Provisioning  Items. The payment provisions of the Customer
Services  General Terms  Agreement  (CSGTA)  between Boeing and Customer will be
applicable  to  Provisioning  Items  ordered  by  Customer  from  Boeing for the
Aircraft.


5.           Delivery.
             --------

             Boeing will,  insofar as reasonably  possible,  deliver to Customer
the Spare Parts  ordered by Customer in accordance  with the  provisions of this
letter on dates reasonably calculated to conform to Customer's anticipated needs
in view of the scheduled  deliveries  of the Aircraft.  Customer and Boeing will
agree upon the date to begin delivery of the Provisioning Spare Parts ordered in
accordance with this letter. Where appropriate, Boeing will arrange for shipment
of such Spare Parts,  which are manufactured by suppliers,  directly to Customer
from the applicable supplier's facility.  The routing and method of shipment for
initial deliveries and all subsequent  deliveries of such Spare Parts will be as
mutually agreed between Boeing and Customer.


6.           Substitution for Obsolete Spare Parts.
             -------------------------------------

             6.1 Obligation to Substitute.  In the event that, prior to delivery
of the first  Aircraft  pursuant  to the  Purchase  Agreement,  any  Spare  Part
purchased  by Customer  from Boeing in  accordance  with this letter is rendered
obsolete or unusable due to the  redesign of the  Aircraft or of any  accessory,
equipment  or part  therefor,  (other  than a redesign at  Customer's  request),
Boeing will deliver to Customer new and usable Spare Parts in  substitution  for
such  obsolete or unusable  Spare Parts and Customer will return the obsolete or
unusable  Spare  Parts to Boeing.  Boeing will credit  Customer's  account  with
Boeing with the price paid by Customer for any such  obsolete or unusable  Spare
Part and will invoice  Customer for the  purchase  price of any such  substitute
Spare Part delivered to Customer.

             6.2  Delivery of Obsolete  Spare  Parts and  Substitutes  Therefor.
Obsolete or unusable Spare Parts returned by Customer pursuant to this Item will
be  delivered  to Boeing  at its  Seattle  Distribution  Center,  or such  other
destination as Boeing may reasonably designate. Spare Parts substituted for such
returned  obsolete or  unusable  Spare  Parts will be  delivered  to Customer at
Boeing's  Seattle  Distribution  Center,  or such other Boeing shipping point as
Boeing may  reasonably  designate.  Boeing will pay the freight  charges for the
shipment from Customer to Boeing of any such obsolete or unusable Spare Part and
for the shipment from Boeing to Customer of any such substitute Spare Part.


7.           Repurchase of Provisioning Items.
             --------------------------------

             7.1  Obligation to  Repurchase.  During a period  commencing 1 year
after delivery of the first Aircraft under the Purchase Agreement,  and ending 5
years after such  delivery,  Boeing  will,  upon receipt of  Customer's  written
request and subject to the exceptions in Paragraph 7.2,  Exceptions,  repurchase
unused and undamaged  Provisioning Items which (i) were recommended by Boeing in
the  Provisioning  Data as  initial  provisioning  for the  Aircraft,  (ii) were
purchased by Customer from Boeing, and (iii) are surplus to Customer's needs.

             7.2  Exceptions.  Boeing will not be obligated under Paragraph 7.1,
Obligation to Repurchase,  to repurchase any of the following: (i) quantities of
Provisioning  Items in excess of those  quantities  recommended by Boeing in the
Provisioning  Data for the  Aircraft,  (ii) QEC Kits,  Bulk Material  Kits,  Raw
Material  Kits,  Service  Bulletin Kits,  Standards Kits and components  thereof
(except those  components  listed  separately in the Provisioning  Data),  (iii)
Provisioning  Items for which an order was received by Boeing more than 5 months
after delivery of the last Aircraft,  (iv) Provisioning  Items which have become
obsolete or have been  replaced by other  Provisioning  Items as a result of (a)
Customer's  modification of the Aircraft or (b) design improvements by Boeing or
the supplier (other than  Provisioning  Items which have become obsolete because
of a defect in design if such defect has not been remedied by an offer by Boeing
or the supplier to provide no charge  retrofit kits or  replacement  parts which
correct such defect), and (v) Provisioning Items which become excess as a result
of a change in Customer's operating  parameters,  provided to Boeing pursuant to
the  Initial  Provisioning  meeting  in  Paragraph  2,  which  were the basis of
Boeing's initial provisioning recommendations for the Aircraft.

             7.3  Notification  and  Format.  Customer  will notify  Boeing,  in
writing,  when Customer  desires to return  Provisioning  Items which Customer's
review  indicates are eligible for  repurchase by Boeing under the provisions of
this Repurchase of Provisioning  Items paragraph.  Customer's  notification will
include a detailed summary,  in part number sequence,  of the Provisioning Items
Customer desires to return. Such summary will be in the form of listings, tapes,
diskettes or other media as may be mutually  agreed between Boeing and Customer,
and will include part number,  nomenclature,  purchase  order  number,  purchase
order date and quantity to be returned.  Within 5 business days after receipt of
Customer's notification,  Boeing will advise Customer, in writing, when Boeing's
review of such summary will be completed.

             7.4 Review and  Acceptance by Boeing.  Upon  completion of Boeing's
review of any detailed summary  submitted by Customer pursuant to Paragraph 7.3,
Boeing will issue to Customer a Material  Return  Authorization  (MRA) for those
Provisioning  Items Boeing agrees are eligible for repurchase in accordance with
this Repurchase of Provisioning Items paragraph.  Boeing will advise Customer of
the reason that any spare part  included in Customer's  detailed  summary is not
eligible  for  return.  Boeing's  MRA will state the date by which  Provisioning
Items listed in the MRA must be  redelivered to Boeing and Customer will arrange
for shipment of such Provisioning Items accordingly.

             7.5  Price  and  Payment.  The  price  of  each  Provisioning  Item
repurchased  by  Boeing  pursuant  to  this  Repurchase  of  Provisioning  Items
paragraph will be an amount equal to 100% of the original invoice price thereof.
In the  case  of  Provisioning  Items  manufactured  by a  supplier  which  were
purchased  pursuant  to  Paragraph  4,  Purchase  from  Boeing of Spare Parts as
Initial  Provisioning  for the Aircraft,  hereof the  repurchase  price will not
include  Boeing's 12% handling  charge.  Boeing will pay the repurchase price by
issuing a credit  memorandum in favor of Customer  which may be applied  against
amounts due Boeing for the purchase of aircraft, Spare Parts, services or data.

             7.6 Delivery of Provisioning Items.  Provisioning Items repurchased
by Boeing pursuant to this  Repurchase of  Provisioning  Items paragraph will be
delivered to Boeing F.O.B.  at its Seattle  Distribution  Center,  or such other
destination  as Boeing may reasonably  designate.  Customer will pay the freight
charges for the shipment from Customer to Boeing of any such Provisioning Items.


     8. Obsolete Spare Parts and Surplus  Provisioning Items - Title and Risk of
Loss.

             Title to and risk of loss of any  obsolete or unusable  Spare Parts
returned to Boeing  pursuant to Paragraph  6,  Substitution  for Obsolete  Spare
Parts, will pass to Boeing upon delivery thereof to Boeing. Title to and risk of
loss of any Spare  Part  substituted  for an  obsolete  or  unusable  Spare Part
pursuant to Paragraph 6,  Substitution  for Obsolete  Spare Parts,  will pass to
Customer  upon  delivery  thereof to Customer.  Title to and risk of loss of any
Provisioning  Item  repurchased by Boeing pursuant to Paragraph 7, Repurchase of
Provisioning  Items,  will pass to Boeing upon delivery thereof to Boeing.  With
respect to the obsolete or unusable  Spare Parts which may be returned to Boeing
and the Spare  Parts  substituted  therefor,  pursuant to  Paragraph  6, and the
Provisioning Items which may be repurchased by Boeing,  pursuant to Paragraph 7,
the party  which has risk of loss of any such  Spare Part or  Provisioning  Item
will have the  responsibility of providing any insurance coverage for it desired
by such party.


9.           Supplier Support.
             ----------------

             Boeing has entered, or anticipates  entering,  into product support
agreements  with  suppliers  (Boeing   Suppliers)  of  major  system  components
manufactured  by  such  Suppliers  to be  installed  on the  Aircraft  (Supplier
Components).  Such product support agreements commit, or are expected to commit,
the Boeing  Suppliers to provide to Boeing's  customers  and/or such  customer's
designees support services with respect to the Supplier  Components which can be
reasonably  expected to be required during the course of normal operation.  This
support  includes  but is not limited to  shelf-stock  of certain  spare  parts,
emergency  spare parts,  timely  delivery of spare  parts,  and  technical  data
related to the Supplier  Components.  Copies of such product support  agreements
will be provided to Customer on or about  September 22, 2000, in Boeing Document
D6-56115,  Volumes  1 and 2. In the event  Customer  has used due  diligence  in
attempting to resolve any  difficulty  arising in normal  business  transactions
between  Customer and a Boeing  Supplier  with respect to product  support for a
Supplier Component  manufactured by such Supplier and if such difficulty remains
unresolved,  Boeing will, if requested by Customer, assist Customer in resolving
such difficulty.  Assistance will be provided by the Customer  Supplier Services
organization.


10.          Termination for Excusable Delay.
             -------------------------------

             In the event of termination of the Purchase  Agreement with respect
to any Aircraft  pursuant to Article 7 of the AGTA,  such  termination  will, if
Customer so requests by written  notice  received by Boeing within 15 days after
such  termination,  also discharge and terminate all obligations and liabilities
of the parties as to any Spare Parts which Customer had ordered  pursuant to the
provisions  of this letter as initial  provisioning  for such Aircraft and which
are undelivered on the date Boeing receives such written notice.


Very truly yours,

THE BOEING COMPANY



By
  ------------------------------------------

Its           Attorney-In-Fact
   --------------------------------------


ACCEPTED AND AGREED TO this

Date:                                , 2000
      -------------------------------

AMERICAN TRANS AIR, INC.



By
  ------------------------------------------

Its
   ------------------------------------------