Fairchild Industries, Inc., of Germantown and its chairman, entered innocent pleas yesterday to charges of violating federal income tax laws by maintaining an alleged corporate slush fund used for political contributions.

A four-count indictment issued Sept. 8 charged the major federal contracting firm and its chairman, Edward G. Uhl, with overstating the firm's capital assets and the deduction for depreciation of the cars used by its executives.

Uhl and a lawyer for the firm appeared before U.S. Magistrate Paul Rosenberg in Baltimore. Uhl was freed on his own recognizance with no trial date set.

The indictment said the firm's executives "individually had agreed to pay and paid to the corporation substantial portions of the cost of those automobiles, which payments were maintained in a fund that was controlled by Edward G. Uhl, then president of the corporation, and was used and intended to be used for political contributions." The firm, however, claimed on its returns that the corporation paid for the cars, the indictment alleged.

The two counts against Uhl charged him with aiding and assisting in the preparation of the false tax returns, while the other two counts charged the corporation with filing the false returns.