Exhibit 10.4  November 21, 2003  To each of the Lenders
parties to the Credit Agreement
(as defined  below) and to Citibank,
N.A.,
as Agent for such Lenders  Ladies and Gentlemen:  Reference is made to the Five-Year Credit Agreement
dated as of November 21, 2003 among The Boeing Company, the lenders parties
thereto, JPMorgan Chase Bank, as syndication agent, Citigroup Global Markets
Inc. and J.P. Morgan Securities, Inc., as joint lead arrangers and joint book
managers, and Citibank, N.A., as Agent for such lenders (as amended or modified
from time to time, the Credit Agreement).  Capitalized terms used in this letter that are not defined herein
have the respective meanings specified in the Credit Agreement.  Please be advised that the Company hereby designates
its undersigned Subsidiary, Boeing Capital Corporation (the Subsidiary
Borrower), as a Subsidiary Borrower under and for all purposes of the
Credit Agreement.  The Subsidiary Borrower, in consideration of each
Lenders agreement to extend credit to it under and on the terms and conditions
set forth in the Credit Agreement, does hereby assume each of the obligations
imposed upon a Subsidiary Borrower as a Borrower under the Credit Agreement
and agrees to be bound by the terms and conditions of the Credit
Agreement.  In furtherance of the
foregoing, the Subsidiary Borrower hereby represents and warrants to each
Lender as follows:  (a)           The
Subsidiary Borrower is a corporation duly organized, validly existing and in
good standing under the laws of the state of Delaware.  The Subsidiary Borrower is qualified to do
business in every jurisdiction where such qualification is required, except
where the failure to so qualify would not have a materially adverse effect on
the financial condition of the Company and the Subsidiary Borrowers as a whole.  (b)           The
execution, delivery and performance by the Subsidiary Borrower of this
Subsidiary Borrower Letter and its Notes, if any, are within the Subsidiary
Borrowers corporate powers, have been duly authorized by all necessary
corporate action, have received all necessary governmental approval, if any
(which approval remains in full force and effect), and do not contravene any
law, any provision of the Subsidiary Borrowers charter or by-laws or any
contractual restriction binding on the Subsidiary Borrower.  
   (c)           This
Subsidiary Borrower Letter does, and the Notes of the Subsidiary Borrower when
duly executed and delivered by the Subsidiary Borrower will, constitute legal,
valid and binding obligations of the Subsidiary Borrower, enforceable against
the Subsidiary Borrower in accordance with their respective terms.  (d)           In
the Subsidiary Borrowers opinion, there are no pending or threatened actions
or proceedings before any court or administrative agency that are reasonably
likely to have a material adverse affect on the financial condition or
operations of the Subsidiary Borrower or any Subsidiary which is likely to
impair the ability of the Subsidiary Borrower to repay the Advances to it or
which would affect the legality, validity or enforceability of such Advances or
its Notes, if any.  (e)           The
Consolidated statement of financial position as of December 31, 2002 and
the related Consolidated statement of earnings and retained earnings for the
year then ended (copies of which have been furnished to each Lender) correctly
set forth the Consolidated financial condition of the Company and its
Subsidiaries as of such date and the result of the Consolidated operations for
such year.  (f)            The
Subsidiary Borrower is not engaged in the business of extending credit for the
purpose of purchasing or carrying margin stock within the meaning of Regulation
U issued by the Board of Governors of the Federal Reserve System, and no
proceeds of any Advance to the Subsidiary Borrower will be used to purchase or
carry any margin stock or to extend credit to others for the purpose of
purchasing or carrying any margin stock. 
Following application of the proceeds of each Advance, not more than 25
percent of the value of the assets (either of the Subsidiary Borrower only or
of the Subsidiary Borrower and its subsidiaries on a consolidated basis)
subject to the provisions of Section 4.2(a) of the Credit Agreement or subject
to any restriction contained in any agreement or instrument between the
Subsidiary Borrower and any Lender or any Affiliate of a Lender relating to
Debt within the scope of Section 6.1(d) of the Credit Agreement will be margin
stock (within the meaning of Regulation U issued by the Board of Governors of
the Federal Reserve System).  (g)           The
Subsidiary Borrower is not an investment company, or an affiliated person
of, or promoter or principal underwriter for, an investment company, as
such terms are defined in the Investment Company Act of 1940, as amended.  Neither the making of any Advances, nor the
application of the proceeds or repayment thereof by the Subsidiary Borrower,
nor the consummation of the other transactions contemplated hereby, will
violate any provision of such Act or any rule, regulation or order of the
Securities and Exchange Commission thereunder.  2 
    Very truly yours,THE BOEING COMPANYBy
  /s/ G. L. CarpenterName: G. L. CarpenterTitle: Assistant TreasurerBOEING CAPITAL CORPORATIONBy
  /s/ Steven W. VogedingName:
  Steven W. VogedingTitle:
  Vice President and
  Chief Financial Officer  3