On 7 June 1920, Boeing was awarded a contract for 20 production models designated GA-1. Before the first was delivered in May 1921, the order had been reduced to ten. The production aircraft wore Boeing constructors' numbers 200-209 and AAC serial numbers 64146-64155. Number 64146 was evaluated at McCook as project P187. The follow-on GA-2 was flown at McCook field in December 1921 with orders to construct two more aircraft.
The GA-1 were sent to Kelly Field, Texas, in early 1923 for service tests with the only US aerial attack formation, the 3rd Attack Group. These tests showed the aircraft to be unacceptable. They had poor visibility and performance, particularly in rate of climb, maneuverability, and range. The aircraft suffered from noise and vibrations caused by the 3/16-inch (4.75mm)-thick armor. Takeoff runs were very long by the standards of the day. The GA-1s were extremely unpopular with the pilots conducting the evaluation.
As a result, in 1925 the entire country's attack air force (3rd Attack Group that is, as differentiated from the bomber force) consisted of fourteen Airco DH-4 machines, inadequate even for training, let alone for combat.
It was rumored that the GA-1s survived until surveyed on 14 January 1926, so that Kelly Field pilots could be threatened with being forced to fly them for disciplinary infractions. All were scrapped in April 1926.