Prototype YP-59A Airacomet
The USAAF ordered a service trials batch of thirteen YP-59A-BEs (serial numbers 42-108771 to 42-108783), which differed from the earlier XP-59A models. Notable changes included a rearward-sliding canopy instead of a sideways-hinged one. Initially, these aircraft were intended to be powered by 1,650 lb st General Electric I-16 engines (later designated J31), but due to delays, they were equipped with I-A engines instead.
The first two YP-59As arrived at Muroc in June 1943, with 42-108772 making its maiden flight on 18 August 1943. With temporary I-A engines, this aircraft achieved a top speed of 389 mph at 35,160 feet and could climb to 30,000 feet in 18.82 minutes. The installation of the I-16 engines later increased the top speed to 409 mph at 35,000 feet. The second YP-59A flew on 15 September 1943, followed by the next aircraft up to number 7. Notably, No. 3 (42-108773) was sent to Britain for comparison with the Gloster Meteor, where it was named Airacomet and received the RAF serial RJ362/G, along with a grey-green camouflage and bright yellow undersides. It flew only eleven times at Farnborough between November 1943 and April 1944 before returning to the United States in early 1945.
The remaining aircraft in the batch served various purposes: Nos. 8 and 9 were delivered to the US Navy in November 1943 (renumbered BuNo 63960 and 63961) and flown until 1947/49, with one crashing and another being scrapped in December 1947. No. 10 (42-108780) was modified for drone control equipment development and was lost on 23 March 1945. Nos. 11 and 12 (42-108781 and 42-108782) were sent to NACA for wind-tunnel experiments. No. 13 (42-108783) was initially used for gunnery tests, which revealed the aircraft’s poor performance as a gun platform. It was later converted into a drone controller aircraft, nicknamed Mystic Mistress, with a second cockpit added in the nose. This modification was also applied to the third prototype and the seventh YP-59A (42-108777).
Spinning trials conducted at the end of December 1943 led to the addition of a small ventral fin to improve spin recovery characteristics. Service tests began at Muroc on 5 December 1944 with three YP-59As. Mock combat sorties against the Lockheed P-38J Lightning and Republic P-47D Thunderbolt revealed that the Airacomet was outclassed by conventional piston-engined fighters, leading to the conclusion that it was unsuitable for combat.