SCHEDULE 14A

                              (Rule 14a-101)

                  INFORMATION REQUIRED IN PROXY STATEMENT
                         SCHEDULE 14A INFORMATION

             Proxy Statement Pursuant to Section 14(a) of the
                      Securities Exchange Act of 1934

Filed by the registrant  X
Filed by a party other than the registrant  __
[ ]_  Preliminary proxy statement            [ ] Confidential, For Use of the
                                                 Commission Only (as permitted
                                                 by Rule 14a-6(e)(2))
[ ]   Definitive proxy statement
[x]   Definitive additional materials
[_]   Soliciting material pursuant to Rule 14a-11(c) or Rule 14a-12

                       McDonnell Douglas Corporation
- ---------------------------------------------------------------------------
             (Name of Registrant as Specified in Its Charter)
- ---------------------------------------------------------------------------
       (Name of Person(s) Filing Proxy Statement, if other than Registrant)

Payment of filing fee (Check the appropriate box):

[X] No fee required
[ ] Fee computed on table below per Exchange Act Rules  14a-6(i)(l) and 0-11 (1)
  Title of each class of securities to which transaction applies:

- ---------------------------------------------------------------------------
  (2)  Aggregate number of securities to which transaction applies:

- ----------------------------------------------------------------------------
  (3) Per unit price or other underlying value of transaction  computed pursuant
to  Exchange  Act Rule 0-11 (set  forth the  amount on which the  filing  fee is
calculated and state how it was determined):

- ----------------------------------------------------------------------------
  (4)  Proposed maximum aggregate value of transaction:

- ----------------------------------------------------------------------------
  (5)  Total fee paid:
- ----------------------------------------------------------------------------
[ ]    Fee paid previously with preliminary materials.

- ----------------------------------------------------------------------------
[ ] Check box if any part of the fee is offset as provided by Exchange  Act Rule
0-11(a)(2)  and  identify  the  filing  for  which the  offsetting  fee was paid
previously.  Identify the previous filing by registration  statement  number, or
the Form or Schedule and the date of its filing.

 (1)  Amount Previously Paid:

- -----------------------------------------------------------------------------
 (2)  Form, Schedule or Registration Statement No.:

- -----------------------------------------------------------------------
 (3)  Filing Party:
- -----------------------------------------------------------------------
  (4)  Date Filed:
- -----------------------------------------------------------------------


The following article will appear in various Company publications:

   If you got more than one ballot, sign and return all of them.

   Did you  receive  more  than one  proxy or  voting  instruction  card for the
special  meeting July 25? If so, you hold  McDonnell  Douglas stock in more than
one  way--as a  shareholder  of  record,  through a bank or  broker,  through an
employee  savings  plan,  through the  employee  Payroll  Stock  Ownership  Plan
(PAYSOP), and/or through other means.

   Each proxy or voting instruction card you receive should be voted separately,
because each applies to different shares.

   Don't forget July 22 is the deadline for the trustee of the savings plans and
PAYSOP to receive your ballot.  Plan  participants are asked when voting to sign
the proxy card. A large  quantity of unsigned  cards have already been received.
These  are  invalid.   The  unsigned  cards  are  currently  being  returned  to
participants for signature;  but the July 22 deadline will prevent this practice
from continuing in the near future.

   And remember:  To pass, the merger requires an affirmative vote by holders of
two-thirds of all outstanding  McDonnell Douglas shares. Not voting can have the
same effect as either  voting  against the  proposal or, for shares in a savings
plan,  permitting the trustee to vote your shares in the same  proportion as the
votes cast by participants who return their ballots.

     The merger proposal will be considered at a special  shareholders'  meeting
July 25 in St. Louis.