Fairchild Industries yesterday reported a 50 per cent gain in both sales and earnings for the first quarter over the same period a year ago.

At a non-eventful annual meeting at its headquarters in Germantown, chairman Edward G. Uhl announced profits of $1,195 million (26 cents a share) on sales of $88,896 million compared with 1976 first quarter income of $796,000 (17 cents a share) on sales of 53,752 million.

Uhl told the stockholders that Fairchild is a month ahead of schedule on its deliveries of the A-10 close air support plane being produced for the Air Force. He said the greater than expected deliveries of the A-10 - 13 for the quarter - contributed "significantly" to the sales and earnings increases. The Air Force contract calls for 51 of the aircraft to be delivered this year.

A backlog of orders for the A-10 is anticipated by the end of 1977, Uhl said, which should carry production of the plane through 1980. Fairchild is "conducting an active international" marketing program to sell the A-10 and is committing itself to further investment in and development of the craft, according to a company spokesman.

Uhl noted that the overall financial health of the company, whose divisions are engaged in the manufacture of spacecraft components, subsystems and industrial products, is strong.He said substantial capital investments will be made at the company's main aircraft plant in New York and at its Swearingen Aviation Corp subsidiary.