Bell XP-76

Infobox Aircraft
name=Bell XP-76
type=Fighter aircraft
manufacturer=Bell Aircraft Corporation


caption=The Bell P-76 was an improved variant of the P-39 Airacobra, shown here.
designer=
first flight=1942
introduced=n/a
retired=
status=Did not enter mass-production
primary user=United States Air Force
more users=
produced=
number built=3
unit cost=
variants with their own articles=

Bell P-76 was the proposed designation for a production model derivative of the XP-39E, a single-engine United States fighter aircraft prototype of World War II.

Background

On 26 February 1941 the USAAC placed a contract with Bell allowing for the purchase of two XP-39Es ("41-19501 and 41-19502") which were envisaged to be a major improvement on the P-39D series. Because of the number of changes proposed the production model was to be called the Bell P-76.

The Bell P-76 was proposed to address the poor high-altitude performance of the P-39 Airacobra by incorporating a new and thicker wing with a symmetrical airfoil; the section chosen was NACA 0018 at the wing-root tapering to an NACA 23009 at the tip. Although the new wing has often been referred to as a laminar flow type, this was not the case. [ [http://www.ae.uiuc.edu/m-selig/ads/aircraft.html UIUC incomplete guide to Airfoil usage] Retrieved: 9 August 2008] The wing span was increased to 35 ft 10 in (10.9 m) and the area to 236 ft² (21.9 m²), the thicker wing allowing an increase in the fuel capacity to 150 US gallons (568 l).Bowers 1979, pp.21-25.]

Design of a new Allison V-1710-E9 was also underway. This version, which had the military designation of V-1710-47, used a two-stage mechanical supercharger to increase the engine power at altitude. However, this engine went through so many design changes that it ended up being almost identical to the later V-1710-93 which was fitted in the XP-63A.

Another change was the engine bay was modified to accept a more powerful engine in lieu of the V-1710. Its origins lie in the 1941 project to equip three P-39D (41-19501, 41-19502 and 42-7164) with the Continental I-1430-1 liquid-cooled supercharged engine. The resultant XP-39E had a symmetrical airfoil wing with square wingtips, an elongated fuselage to accommodate the larger engine, and revised air intakes and radiators. The three prototypes each had a different tailfin. Since the Continental engine was not available at rollout, the prototypes flew with Allison V-1710-47 engines. In 1942, the XP-39E was redesignated XP-76. Although 4,000 aircraft were initially ordered, the order was cancelled to permit the Bell factory to manufacture B-29 Superfortress bomber aircraft under license from Boeing. Many of the lessons learned in the XP-76 were implemented in the subsequent Bell P-63 Kingcobra.

pecifications (XP-76)

aircraft specifications

plane or copter?=plane
jet or prop?=prop

crew=1
length main=31 ft 11 in
length alt=9.7 m
span main=35 ft 10 in
span alt=10.9 m
height main= ft in
height alt= m
area main=236 ft²
area alt=21.9 m²
empty weight main=6,936 lb
empty weight alt=3,150 kg
loaded weight main=
loaded weight alt=
max takeoff weight main=8,918 lb
max takeoff weight alt=4,050 kg

engine (prop)=
type of prop=Continental I-1430-1
number of props=1
power main=2,100 hp
power alt=1,600 kW

max speed main=386 mph
max speed alt=335 knots, 620 km/h
max speed more=at 21,680 ft (6,600 m)
range main=
range alt=
ceiling main=
ceiling alt=
climb rate main=2,150 ft/min
climb rate alt=11 m/s
loading main=
loading alt=
power/mass main=
power/mass alt=

guns=
** 1× 37 mm (1.46 in) Oldsmobile T9 cannon, 30 rounds
** 2× 0.50 in (12.7 mm) M2 Browning machine guns, 200 rounds per gun
** 4× 0.30 in (7.62 mm) M1919 machine guns, 1,000 rounds per gun
bombs=500 lb (227 kg) externally

References

Bibliography

*Bowers, Peter M. "Airborne Cobra Pt.II". "Airpower magazine, Vol.9, No.1, January 1979."

ee also

aircontent

related=
* P-63 Kingcobra

similar aircraft=
* P-39 Airacobra
* P-63 Kingcobra