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Hybrid Aircraft - North American XP-82/P-82/F-82 Twin Mustang
The
Twin Mustang was conceived in 1943 as an ultra long range escort fighter
with accommodation for a relief pilot. During WW.2 the belief had developed that
an escort fighter needed two engines and a crew of two. The P-51 itself disproved
those assumptions when it escorted 8th AF bombers deep into Germany. However,
the greater distances of the Pacific war, and the advent of the B-29 Superfortress
bomber, revived the idea, with an expectation that fighter crews, like their bomber
counterparts, might face six to eight hours in the cockpit.
The proposal was to join two P-51H airframes by means of a constant-chord centre
section and rectangular tailplane, retaining a port and starboard outer wing but
deleting the remaining outer tail surfaces.
The
pilot, with full flight and engine instruments, occupied the port cockpit, and
a co-pilot sat in the starboard cockpit with sufficient instruments to control
the aircraft to relieve the pilot or in an emergency.
The undercarriage was to consist of a single main wheel between each fuselage
and the centre section, and twin tailwheels. Design work began in January 1944,
and the first flight by one of the two prototypes designated XP-82 was on April
15, 1945. It was powered by two Packard Merlin V-1650-23/25 engines of
1,860 hp.
By this time, 500 production aircraft, designated P-82B, were on order. These were essentially similar to the prototypes, but had wing racks for four
1,000 lb (453.5 kg) or two 2,000 lb (907 kg) bombs, twenty-five 5-in (12.7 cm)
rockets, or a central pod supplementing the six inbuilt .5 in (12.7mm) machine
guns with a further eight similar weapons. The third prototype differed in having
Allison V-1710-119 engines with airscrews rotating in the same direction.
The end of the Pacific war saw a cut-back in production orders of the P-82B to
twenty aircraft. One of these, Betty Jo, establishing a number of distance records,
including a non-stop flight between Honolulu and New York on 28th February, 1947,
in 14 hours and 32 minutes covering 5,051 miles. This stood into the 1990s as
the longest unrefuelled flight by a piston-engined fighter.
Two
of this batch were completed as night-fighters; a P-82C (with SCR-720 airborne
intercept radar) and a P-82D (with APS-4 radar). The radar was housed in a large
nacelle under the wing centre section. Other equipment included an APN-1 radar
altimeter and APS-13 tail warning. The starboard cockpit was adapted to house
the radar operator.
In 1947, orders were placed for 250 additional Twin Mustangs, the first
100 to be P-82E (later designated F-82E) day fighters, for escort and ground attack,
and the remainder to be night-fighters. These would comprise 91 P-82Fs with APS-4
radar, and 59 P-82-Gs with SCR-720 radar.
All three versions would be powered by the Allison V-1710-143/145 engines. From
June 1948 all three types were redesignated F-82E, F-82F and F-82G.
The F-82E served as a long-range escort with Strategic Air Command between 1948
and 1950. The Twin Mustang entered service with the USAF's Air Defense
Command, succeeding the P-61 Black Widow, and was subsequently deployed
overseas with the 5th Air Force in Japan, operating over Korea in the early stages
of the Korean War.
An F-82G of the 68th (All-Weather) Squadron was credited with the destruction
of the first enemy aircraft on June 27th, 1950. After withdrawal from service in the Far East Air Force, fourteen F-82F and F-82G
Twin Mustangs were winterised, redesignated F-82H, and assigned to Alaska.
Only five Twin Mustangs are known to have survived into the 1990s, and
none of them were airworthy. The Confederate Air Force at Midland, Texas, undertook
restoration of a P-82D to flying condition, delayed somewhat as they sought a
left-handed propellor.
| North
American F-82E data: |
SPAN:
51 ft. 3 in. (15.62 m.)
LENGTH:
39 ft. 1 in. (11.9 m.)
HEIGHT:
13 ft. 10 in. (4.2 m.)
WING AREA:
408 sq. ft. (37.9 m²)
EMPTY WEIGHT:
14,914 lb. (6764.5 kg.)
LOADED WEIGHT:
24,813 lb. (11255 kg.)
MAX. OVERLOAD:
24,864 lb. (11278 kg.)
CRUISING SPEED:
280 mph
MAX. SPEED:
482 mph (748 kmh)
at 21,000 ft. (6400 m) |
SERVICE CEILING:
40,000 ft. (12192 m)
NORMAL RANGE:
2,504 mls. (4030 km)
FERRY RANGE:
2,708 mls (4358 km)
ARMAMENT:
Six .50-cal. machine guns,
25 five-inch rockets, and
4,000 lbs. of bombs
ENGINES:
Two Packard V-1650s
of 1,380 hp. ea.
SCHEMATIC DIAGRAM:
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Related links:
Lockheed RP-38
A P-38 Lightning was used as a testbed to prove the twin-cockpit design of the Mustang.
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