Early wind tunnel reports had pinpointed directional instability but the "fix" of a larger tail would not be ready in time for flight testing.[2] The first prototype was flown on 25 February 1945, by Bell's chief test pilot Jack Woolams, who found it to be underpowered and unstable. The limited flight testing provided satisfactory flight characteristics although spins were restricted until the larger tailfin was installed. The second prototype did incorporate the extended tail and an aileron boost system.[3] One unique characteristic was the XP-83's refusal to "slow down" due to its sleek aerodynamic shape and lack of drag brakes; test pilots were forced to fly very long and flat landing approaches.[4]
The first prototype was used in 1946 as a ramjet testbed, with an engineer's station located in the fuselage behind the pilot and on 14 September 1945 one of the ramjets caught fire - the pilot "Slick" Goodlin and engineer Charles Fay had to parachute out. The second prototype flew on 19 October and was scrapped in 1947. Apart from range, the XP-83 was inferior to Lockheed's P-80 Shooting Star, and the XP-83 project was canceled in 1947.