The Bell XP-83, later known as the ZXF-83, was a prototype escort fighter developed by the United States during World War II.
As one of the early jet fighters, it suffered from insufficient power and was quickly surpassed by more advanced models.
These early jets were notorious for their high fuel consumption, which greatly limited their operational range and endurance.
In response to a request from the United States Army Air Forces in March 1944, Bell was tasked with designing a fighter with enhanced endurance.
A contract for two prototypes was officially signed on July 31, 1944.
Bell’s “Model 40” interceptor, in development since 1943, was repurposed as a long-range escort fighter, maintaining the basic design of the P-59 Airacomet.
The aircraft featured two General Electric J33-GE-5 turbojet engines embedded in the wing roots, allowing the spacious fuselage to accommodate fuel tanks and weaponry.
The all-metal semi-monocoque fuselage could hold 1,150 gallons (4,350 litres) of fuel, with the option to add two 250-gallon (950-litre) drop tanks.
The pressurised cabin was topped with a small, low-profile bubble canopy, and the planned armament consisted of six 0.5-inch (12.7 mm) machine guns mounted in the nose.
The initial test flight of the first prototype took place on February 25, 1945, under the command of Bell’s chief test pilot, Jack Woolams.
Woolams reported that the aircraft displayed satisfactory flight characteristics, despite being somewhat underpowered.
The anticipated instability was indeed present, with spins being successfully avoided until a larger tail fin was installed.
The second prototype, on the other hand, featured a modified tail design and an Aileron boost system.
Notably, the aircraft exhibited unusually high landing speeds, attributed to various factors such as the absence of drag brakes on the XP-83, as well as its streamlined aerodynamics and relatively high minimum thrust settings typical of early jet planes.
Consequently, test pilots were compelled to execute “stabilised approaches,” involving extended and shallow landing trajectories.
Specifications
Crew
1
Length
44 ft 10 in (13.67 m)
Wingspan
53 ft 0 in (16.15 m)
Height
15 ft 3 in (4.65 m)
Wing area
431 sq ft (40.0 m2)
Empty weight
14,105 lb (6,398 kg)
Gross weight
24,090 lb (10,927 kg)
Max take-off weight
27,500 lb (12,474 kg)
Fuel capacity
1,154 US gal (961 imp gal; 4,370 l)
+
2x 300 US gal (250 imp gal; 1,100 l) drop tanks
Powerplant
2 × General Electric XJ33-GE-5 centrifugal flow compressor turbojet engines,
4,000 lbf (18 kN) thrust each for take-off at 11500 rpm
Performance
Maximum speed
522 mph (840 km/h, 454 kn) at 15,660 ft (4,773.2 m)
Range
1,730 mi (2,780 km, 1,500 nmi) on internals
Ferry range
2,050 mi (3,300 km, 1,780 nmi) with drop tanks
Service ceiling
45,000 ft (14,000 m)
Rate of climb
5,650 ft/min (28.7 m/s)
Time to altitude
30,000 ft (9,144 m) in 11 minutes 30 seconds
Wing loading
56 lb/sq ft (270 kg/m2)
Thrust/weight
0.33
Armament
Guns
6 × .50 in (12.7 mm) M2 machine guns
Or
6 × .60 in (15.2 mm) T17E3 machine guns (prototypes)
Or
4 × 20 mm (0.79 in) Hispano cannons
Or
1 × 37 mm (1.46 in) cannon in the nose
Bombs
2 × 1,000 lb (454 kg) bombs.
Sources
U.S. Experimental & Prototype Aircraft Projects: Fighters 1939–1945-B Norton.
The American Fighter from 1917 to the present – E Angelucci.
