Because the plane was underpowered, the United States Army Air Forces (USAAF) was not impressed by its performance and canceled half of the original order for 100 fighters, using the completed aircraft as trainers.

Major General Henry H. "Hap" Arnold became aware of the UK's jet program when he attended a taxiing demonstration of the Gloster E.28/39 in April 1941.

[3][4] The crated prototype had been built on the second floor of a disused Trico Plant 2 factory, but its components were too big to fit through any elevator and required a hole to be broken in the brick outer wall to remove the first XP-59A.

After one flight on 11 March, security concerns caused the jet to be transferred to nearby Harper Lake where it remained until 7 April.

[5][6] Five of the Airacomets, a pair of XP-59As, two YP-59As, and a P-59B had open-air flight observer cockpits (similar to those of biplanes) fitted in the nose with a small windscreen, replacing the armament bay.

The XP-59As were used for flight demonstrations and testing, but one of the latter pair was used as a "mother ship" for the other modified YP-59A during remote control trials in late 1944 and early 1945.

The Army Air Force conducted combat trials against propeller-driven Lockheed P-38J Lightning and Republic P-47D Thunderbolt fighters in February 1944 and found that the older aircraft outperformed the jet.

[10][11] Even as deliveries of the YP-59As began in July 1943, the USAAF had placed a preliminary order for 100 production machines as the P-59A Airacomet, the name having been chosen by Bell employees.

[12][13] The 13 service test YP-59As had a more powerful engine than their predecessor, the General Electric J31, but the performance improvement was negligible, with top speed increased by only 5 mph and a reduction in the time they could be used before an overhaul was needed.

One of these aircraft, the third YP-59A (S/n: 42-108773) was supplied to the Royal Air Force (receiving British serial RJ362/G), in exchange for the first production Gloster Meteor I, EE210/G.