Fairchild Industries, an aerospace and communications company, yesterday received a $413 million contract from the U.S. Air Force to build an additional 144 A-10 Thunderbolt II close air support aircraft.

The award, which increases the Germantown, Md.-based firm's backlog of contracts to $1.3 billion, "reflects continued strong business growth in commercial and military prime aircraft, subcontracts and accessories," said Fairchild President John F. Dealy. "The new contract further enhances Fairchild's already solid base for increased sales and earnings over the next few years."

The order increases to 483 the number of A-10s under contract with the Air Force out of the 733 aircraft production requirements through January 1983.

As of April 26 Fairchild delivered 200 production aircraft to the Air Force.

The firm reported last week first quarter earnings of $7.6 million ($1.56 a share) on sales of $155,484,000 compared to earnings of $5.8 million ($1.22 a share) on sales of $120,724,000 during the first three months last year.

The increase in earnings was principally due to the greater sales of both military and commercial aircraft, Dealy said at the firm's stockholders meeting last week.