Bell P-63 Kingcobra
The Kingcobra’s design evolution began in February 1941, when Bell proposed Models 23 and 24 as improved P-39s with larger wings and alternative Allison and Continental engines. Model 23 became the XP-39E ordered in April and flown early in 1942 with a conventional airfoil section and an Allison V-1710-47 engine with a two-stage supercharger.
Two XP-63 prototypes were ordered on June 27, 1941, with a laminar-flow airfoil and a Continental engine. When progress with the Continental fell behind, in February 1942 the Allison V-1710-47 and square-cut tail of the XP-39E was chosen for the XP-63. Robert M. Stanley flew the first XP-63 on December 7, 1942, one year after the attack on Pearl Harbor.
The Kingcobra’s general arrangement was similar to the P-39s, with the Allison behind the pilot and tricycle gear, but the larger P-63 could be distinguished by its square-cut tail, wider wings, and four-bladed propeller. Bell’s favorite armament of the 37-mm M-4 cannon
with 30 rpg and twin .50-caliber guns with 250 rpg was mounted in the nose.
A production prototype, the XP-63A, had been ordered on September 24, 1942, and a contract for 3,200 production aircraft, Bell Model 33, was approved October 12, 1942. While both XP-63 prototypes were wrecked during tests, the XP-63A was flown on April 26, 1943. This prototype, powered by a V-1710-93 with a two-stage supercharger, added two .50-caliber guns attached under the wings and provided with 200 rpg, 123 pounds of armor, and provisions for a 75-gallon drop tank or 500-pound bomb beneath the fuselage.
Production began with 50 similar P-63A-1s, and when the first seven were accepted in October 1943, the AAF was planning to equip five fighter groups of the Ninth Air Force, based in England, with Kingcobras. But on November 10, 1943, it was decided to use only P-47D and P-51B fighters in all Ninth Air Force groups. Those fighters had superior speed and room in their fuselages for much more fuel. Although P-63As replaced P-39s in AAF fighter groups training in the United States, they never went overseas with AAF units. Instead, the P-63 would fill lend-lease commitments to the USSR.
Weight gradually increased with successive additions to armor and external loads. In January 1944, armor weight increased to 179 pounds for the P-63A-5 block, then to 189 pounds on the A-8, and 199 pounds on the A-9. Beginning with block P-63A-6, two 75-gallon drop tanks or 500-pound bombs could be attached under the wings, and a 64-gallon flush ferry tank could be attached to the belly. In July 1944, ammunition for the new 37-mm M-10 gun was increased to 58 rounds on the P-63A-9. The P-63A-10 had 236 pounds of armor, provision for six rockets in tubes under the wings, and slightly larger stabilizers.
Except for three P-63A-6s shipped to North Russia in February 1944, most Kingcobras were flown to Alaska and turned over at Ladd Field to Soviet pilots, who then flew them to Siberia. On June 14, the first P-63A-7s began arriving at Ladd, but turnover to the Russians was delayed by mechanical problems. Another interruption to deliveries happened on October 7, when a serious rear fuselage weakness grounded the P-63A-10 until 223 aircraft in transit were modified, and deliveries resumed.
Of 1,725 P-63A models completed by December 1944, 1,324 had been turned over to the USSR, and a P-63A-6 reached the RAF in May 1944, followed later by a P-63A-9. From January to June 1945 Bell delivered 1,227 P-63Cs, which had the V-1710-117, 201 pounds of armor, an extended fin under the tail, and 1,076 went to the USSR.
The last two P-63C-5s reached Siberia in August 1945, just before Japan surrendered. Although 21 Kingcobras were lost in transit in North America, they were replaced, so that the Red Army Air Force received 2,400 of the 3,303 built by Bell, including experimental and target types. Most VVS fighter missions were less than two hours, so the limited fuel capacity was not a problem, and the wing guns were often omitted in Soviet service.
All this production and delivery effort resulted in the destruction of only one Axis plane, a Japanese fighter shot down during the invasion of Manchuria. The first P-63A regiment, the 28th IAP, was part of the Moscow area PVO, but there had been no raids on Moscow for three years. Most Kingcobras were still in Siberia when Germany had been defeated in May 1945. For the war against Japan in August, they equipped the 190th and 245th fighter air divisions (IAD) on the Transbaikal Front, while the 410th and 88th IAPs on Kamchata supported the attack on the Kuriles, and P-63s served the Soviet Pacific Fleet’s 7th IAD. That division’s 17th IAP scored the Kingcobras sole recorded victory over a Japanese fighter on August 15, 1945.
After the war, P-63s were flown by several VVS divisions and naval fighter regiments, until replaced by MiG-15 jets. As late as 1952, the P-63C was involved in Cold War episodes, when eight were destroyed by P-80s strafing a VVS base near Vladivostok, and those with a Soviet fighter regiment in Siberia unsuccessfully attempted to intercept RB-47 spy planes.
France also had the P-63C-5, receiving 114 from April to July 1945 as the war ended in Europe. From August 1949 to April 1951, four French groups flew ground support missions in Viet Nam.