History
Design and Development
With the first of the first-generation fighters being around, the early turbojet engines were too restrictive for the jet fighters as they tended to be too heavy, underpowered, and super-thirsty for fuel. Bell’s P-59 Airacomet was an example of this problem. In March 1944, the USAAF requested Bell Aircraft Corporation to design and develop a jet fighter with increased endurance and uprated turbojets to solve the restrictive performance problem. In addition, the USAAF was seeking a new long-range, fast fighter capable of escorting B-29s over 1,000 miles.
Experienced chief design engineer Robert J. Woods and his design team led the design of the long-range offensive pursuit jet airplane that potentially could satisfy the USAAF’s needs. The design had been worked on since March 1943, and then it was redesigned to meet the long-range escort fighter requirement.
With the Model 40 designation, the revised design retained the basic overall configuration of the earlier P-59A Airacomet, and it was to be powered by two General Electric J33-GE-5 turbojet engines installed in the wing roots adjacent to the fuselage. The powerplant provided a total of 8,000 lbf thrust. This arrangement allowed the large and bulk fuselage to be free for fuel tanks and armament, and it allowed the aircraft to have fair maneuverability, even if one engine failed. The fuselage was an all-metal semi-monocoque capable of carrying 1,150 gallons (4,350 L) of fuel. In addition, two 250 gal (950 L) drop tanks could be carried. The aircraft was fitted with a fully retractable tricycle undercarriage. The cabin was pressurized and had a small and low bubble-style canopy. The proposed armament was to be six 0.50-cal. machine guns with 300 rounds per gun, and all guns were to be mounted in the nose. Alternative configurations of six 15.2-mm machine guns or four 20-mm/37-mm cannons could be used.
Bell’s Model 40 proposal was well received, especially when it highlighted endurance as an important feature, so the USAAF ordered the wind tunnel models on March 24, 1944, and awarded Bell a contract for two XP-83 prototypes on July 21, 1944. The first XP-83 was expected to fly in one year. However, in the early wind tunnel reports, they found a directional instability, and the fix of a larger tail would have to wait until later after the flight testing.
Flight Testing
Only seven months after the contract, the first XP-83 aircraft (44-84990) was completed on February 8, 1945. On February 25, It made a successful flight testing out of Niagara Airport adjacent to Niagara Falls, New York. It was reported to have satisfactory flight characteristics, although it was underpowered and somewhat unstable, confirming the wind tunnel reports of expected instability.
The second XP-83 (44-84991) flew out of Niagara Airport on October 19, 1945. It incorporated a modified vertical tail, with an 18-inch extension, to fix the instability and a new aileron boost system. It had a slightly different bubble canopy and a longer nose to accommodate a heavier armament of six 0.60-in (15.2-mm) T17E3 machine guns. This aircraft was ferried and used in gunnery tests at Wright Field, Ohio. The T17E3 machine guns were based on the German MG 151 and were manufactured by the US Army Corps of Engineers at its Rock Island Arsenal facility, Rock Island, Illinois.
The performance of the XP-83 was concluded to be lackluster, so no P-83 series production was ordered. Apart from the XP-83’s superior range, the XP-83 offered no improvement over the Lockheed P-80 Shooting, which the P-80 still possessed significant advantages in maneuverability and top-speed performance. Additionally, the North American P-82 Twin Mustang, with a superior range, was accepted into production. These factors had ended the XP-83 development project.
Epilogue
Following the project’s cancellation, the first one was used as a testbed in a ramjet engine test program, in which a pair of experimental ramjets were slung under the wings. The test prototype aircraft was intended to fly on ramjet power only once sufficient flying speed was obtained. A hatch was cut in the belly to allow entry into the aft fuselage, and an engineer’s station was installed in the fuselage behind the pilot. However, on September 14, 1946, just as the test program started, one of the ramjets caught fire during a test flight, forcing the pilot and engineer to bail out safely. The XP-83 was destroyed in the crash. The second prototype flew on and completed its tenure at Wright Field, where it was used to test the 0.60-cal. TM17E3, and by 1947, it was declared surplus and later scrapped. No XP-83 aircraft survives to this day.
