Exhibit 5.1

                       CONSENT OF INDEPENDENT ACCOUNTANTS

            We hereby consent to the incorporation by reference in the
Registration Statement of PEC Solutions, Inc. on Form S-8 (No. 333-35538) of
PEC Solutions, Inc. of our report dated February 7, 2001, relating to the
consolidated financial statements of Troy Systems, Inc. and subsidiary.

                                           /s/ Rubino & McGeehin, Chartered

Bethesda, MD
February 1, 2002