John F. Dealy, president of Fairchild Industries Inc. until his unexpected resignation in February, has become of counsel to the law firm of Shaw, Pittman, Potts & Trowbridge. Dealy said last week he would work on a part-time advisory basis to "help the firm's practice grow" in the areas of aerospace and telecommunications law.

Dealy spent 14 years at Fairchild Industries, the aerospace and electronics conglomerate located in Germantown. He was instrumental in several of the corporate moves that helped build Fairchild's annual revenues to about $1.2 billion, including development of its American Satellite subsidiary and its acquisition of Swearingen Aviation Corp. of San Antonio. No official reasons were given for his departure.

Since leaving Fairchild, Dealy has become a distinguished professor at the Georgetown University School of Business Administration and chairman of the Maryland Gov. Harry Hughes' special Committee on High Technology.

Bruce Smith has been appointed senior vice president of Software AG of North America Inc. He was formerly vice president of engineering for Eaton-Kenway Corp.

Francis Castaignede has been promoted to senior vice president of Tesdata Systems Corp. He was most recently vice president of the corporation's European operations.

In a related development, David M. Planning has become vice president of field operations for Tesdata.

Jeffrey Whitesall has been named vice president of Sistemas Inc., a computer consulting firm. Whitesall has been a senior systems analyst and project manager for the company.

Eric Neuman has become of counsel to the law offices of Lee F. Holdmann. He was formerly associated with Hogan & Hartson.

William G. Whyte has been elected world president of United Services Organization. Whyte was formerly vice president of public affairs for U.S. Steel Corp.

Peter Stanzel has become vice president of Lupfer & Long Inc., a software development and marketing firm with offices here and in Boston and Hanover, N.H. Stanzel joined the firm in 1979 and was most recently general manager of its New England operations.