January 7, 1999



Board of Directors
LMI Aerospace, Inc.
3600 Mueller Road
St. Charles, Missouri  63302

  Re:      Registration Statement on Form S-8
           LMI Aerospace, Inc. Profit Sharing and Savings Plan and Trust
           LMI Aerospace, Inc. 1998 Stock Option Plan
           1989 Employee Incentive Stock Option Plan

Gentlemen:

         We have served as counsel to LMI  Aerospace,  Inc.  (the  "Company") in
connection  with various legal matters  relating to the filing of a registration
statement on Form S-8 (the "Registration  Statement") filed under the Securities
Act of 1933, as amended, and the Rules and Regulations  promulgated  thereunder,
relating to a total of  2,424,086  shares of common  stock of the  Company,  par
value $0.02 per share (the  "Shares"),  that may be offered and sold through the
LMI  Aerospace,  Inc.  Profit  Sharing  and  Savings  Plan  and  Trust,  the LMI
Aerospace,  Inc.  1998 Stock Option Plan and the 1989 Employee  Incentive  Stock
Option Plan (collectively, the "Plans").

         We have examined such corporate  records of the Company,  such laws and
such other  information  as we have deemed  relevant,  including  the  Company's
Restated Articles of  Incorporation,  as amended,  the Bylaws,  as amended,  the
Plans,  certain  resolutions  adopted by the Board of  Directors  of the Company
relating  to the  Plans and  certificates  received  from  state  officials.  In
delivering this opinion, we have assumed the genuineness of all signatures,  the
authenticity  of all documents  submitted to us as originals,  the conformity to
the originals of all  documents  submitted to us as  certified,  photostatic  or
conformed  copies,  and the  correctness  of all  statements  submitted to us by
officers of the Company.

         Based upon the foregoing, it is our opinion that:

         1.       The  Company  is  a  corporation  duly  incorporated,  validly
                  existing and in good  standing  under the laws of the State of
                  Missouri.

         2.       All Shares  outstanding  under the LMI Aerospace,  Inc. Profit
                  Sharing  and  Savings  Plan and Trust are  validly  issued and
                  outstanding, and will be fully paid and nonassessable.

         3.       All shares  issuable under the Plans,  if issued in accordance
                  with such Plans,  will be, when so issued,  validly issued and
                  outstanding, and fully paid and non-assessable.

         We consent to the use of this opinion as an exhibit to the Registration
Statement  and to the use of our  name in the  Registration  Statement.  We also
consent to your filing copies of this opinion as an exhibit to the  Registration
Statement  with  agencies of such states as you deem  necessary in the course of
complying  with the laws of such  states  regarding  the  offer  and sale of the
Shares pursuant to the Plans.

                                            Very truly yours,


                                            /s/ Gallop, Johnson & Neuman, L.C.
                                            GALLOP, JOHNSON & NEUMAN, L.C.