Although the XP-39E proved to be disappointing, the USAAF was nevertheless interested in an even larger aircraft based on the same basic layout. Even before its first flight, the USAAF placed an order on 27 June 1941 for two prototypes of an enlarged version powered by the same V-1710-47 engine. The new design was given the designation XP-63 and serials were 41-19511 and 41-19512. A third prototype was also ordered, 42-78015, this one featuring the Packard V-1650, the U.S.-built version of the Rolls-Royce Merlin engine.
The XP-63 was larger in all dimensions than the Airacobra. The laminar flow wings increased the overall span by 4.33 feet to 38.33 feet. The engine was fitted with a second supercharger supplementing the normal single-stage supercharger. At higher altitudes when additional boost was required, a hydraulic clutch would engage the second supercharger, adding 10,000 feet to the service ceiling. A larger four-bladed propeller was also standardized. A persistent complaint against the Airacobra was that its nose armament was not easily accessible for ground maintenance, and in order to cure this problem, the XP-63 airframe was fitted with larger cowling panels.
In September of 1942, even before the prototype flew, the USAAF ordered it into production as the P-63A (Model 33). The P-63A's armament was to be the same as that of the then-current P-39Q, a single 37 mm cannon firing through the propeller hub, two .50 caliber machine guns in the upper nose, and two .50 caliber machine guns in underwing gondolas.
The first prototype, 41-19511, flew for the first time on 7 December 1942, the first anniversary of Pearl Harbor. It was destroyed on 28 January 1943 when its landing gear failed to extend. The second prototype, 41-19512, followed 5 February 1943. It too was destroyed, this time due to an engine failure. The Merlin-engined 42-78015 was later delivered with another Allison instead, as the Merlins were primarily needed for the P-51 Mustang. Nevertheless the new -93 version of the Allison had a war emergency rating of 1,500 hp at sea level, making this prototype one of the fastest Kingcobras built, attaining 421 mph at 24,100 feet.
Deliveries of production P-63As began in October 1943. The USAAF concluded the Kingcobra was inferior to the Mustang, and declined to order larger quantities. American allies, particularly the Soviet Union, had a great need for fighter aircraft, however, and the Soviets were already the largest users of the Airacobra. Therefore, the Kingcobra was ordered into production to be delivered under Lend-Lease. The Soviet Government sent a highly experienced test pilot, Andrey G. Kochetkov, and an aviation engineer, Fiodor Suprun, to the Bell factories to participate in the development of the first production variant, the P-63A. Initially ignored by Bell engineers, Kochetkov's expert testing of the machine's spin characteristics (which led to airframe buckling) eventually led to a significant Soviet role in the development. Amusingly, after flat spin recovery proved impossible, and upon Kochetkov's making a final recommendation that pilots should bail out upon entering such a spin, he received a commendation from the Irving Parachute Company.
P-63A-8, SN 269261, was extensively tested at TsAGI in the world's largest wind tunnel at the time. Soviet input in the development was significant. With the USSR being the largest buyer of the aircraft, Bell was quick to implement their suggestions. The vast majority of the changes in the A sub-variants were a direct result of Soviet input, e.g. increased pilot armor and fuselage hardpoint on the A-5, underwing hardpoints and extra fuel tanks on the A-6, etc. The Soviet Union even experimented with ski landing gear for the P-63A-6, but this never reached production. Most significantly, Soviet input resulted in moving the main cannon forward, favorably changing the center of gravity, and increasing its ammo load from 30 to 58 shells for the A-9 variant. The P-63 had an impressive roll rate, besting the P-47, P-40, N1K2 and P-51 with a rate of 110° per second at 275 mph.[2]
[edit] Operational service
USAAF P-63A USAF photoAir Transport Command ferry pilots, including U.S. women pilots of the WASP program, picked up the planes at the Bell factory at Niagara Falls, New York, and flew them to Great Falls, Montana and then onward via the Alaska-Siberia Route (ALSIB), through Canada, over Alaska where Russian ferry pilots, many of them women, would take delivery of the aircraft at Nome [3] and fly them to the Soviet Union over the Bering Strait. A total of 2,397 such aircraft were delivered, out of the overall 3,303 production aircraft (72.6%).[4]
By a 1943 agreement, P-63s were disallowed for Soviet use against Germany and were supposed to be concentrated in the Soviet Far East for an eventual attack on Japan. However, there are many unconfirmed reports from both the Soviet and German side that P-63s did indeed see service against the Luftwaffe. Most notably, one of Pokryshkin's pilots reports in his memoirs published in the 1990s that the entire 4th GvIAP was secretly converted to P-63s in 1944, while officially still flying P-39s. One account states they were in action at Königsberg, in Poland and in the final assault on Berlin. There are German reports of P-63s shot down by both fighters and flak. Nevertheless, all Soviet records show nothing but P-39s used against Germany.
In general, official Soviet histories played down the role of Lend-Lease supplied aircraft in favor of local designs, but it is known that the P-63 was a successful ground attack aircraft in Soviet service. The Soviets developed successful group aerial fighting tactics for the Bell fighters and P-39s scored a surprising number of aerial victories over German aircraft, mostly Stukas and bombers but including many advanced fighters as well. Low ceilings, short missions, good radios, a sealed and warm cockpit and ruggedness contributed to their effectiveness. To pilots who had once flown the tricky Polikarpov I-16, the aerodynamic quirks of the mid-engined aircraft were unimportant. In the Far East, P-63 and P-39 aircraft were used in August Storm, the Soviet invasion of Manchukoku and northern Korea, where a Soviet P-63A downed a Japanese fighter aircraft, an Army Nakajima fighter, Ki-43, Ki-44 or Ki-84, off the coast of North Korea. Sufficient aircraft continued in use after the war for them to be given the NATO reporting name of Fred. Some American pilots also reported seeing P-63s in service with North Korea during the Korean War.[citation needed]
In 1945, 114 later models were delivered to the French Armée de l'Air, but they arrived too late to see service in World War II. They however saw service during the First Indochina War before being replaced in 1951.
General characteristics
Crew: 1
Length: 32 ft 8 in (10.0 m)
Wingspan: 38 ft 4 in (11.7 m)
Height: 12 ft 7 in (3.8 m)
Wing area: 248 ft² (23 m²)
Empty weight: 6,800 lb (3,100 kg)
Loaded weight: 8,800 lb (4,000 kg)
Max takeoff weight: 10,700 lb (4,900 kg)
Powerplant: 1× Allison V-1710-117 liquid-cooled V-12, 1,800 hp (1,340 kW)
Performance
Maximum speed: 410 mph (660 km/h) at 25,000 ft (7,620 m)
Range:
Combat: 450 mi (725 km)
Ferry: 2,200 mi (3,540 km)
Service ceiling 43,000 ft (13,100 m)
Rate of climb: 2,500 ft/min (12.7 m/s)
Wing loading: 35.48 lb/ft² (173.91 kg/m²)
Power/mass: 0.20 hp/lb (0.34 kW/kg)
Armament
1× 37 mm M4 cannon firing through the propeller hub
4× 0.50 in (12.7mm) M2 Browning machine guns (two in the nose, two in the wings)
The P-63 IIRC could out run the La-7 on the deck. And the A-9 had 58 37mm cannon bullets instead of the regular 30 as they moved it foward. The P-63 would be a great plane in AHII because of how fast it is on the deck. And supposedly, one of the 2nd leading allied ace's squadron had been issued them.
(remember I got this from wikipedia, so please correct me if I'm wrong.)
