Reading level:

Bell P-63 Kingcobra

Bell Aircraft · Fighter · USA · WWII (1939–1945)

Bell P-63 Kingcobra — Fighter
Open in interactive gallery →

The Bell P-63 Kingcobra was the larger, more-powerful successor to the Bell P-39 Airacobra. Bell Aircraft built 3,303 P-63s between 1942 and 1945. Like the P-39, the Kingcobra used the unusual mid-fuselage Allison V-1710 engine driving the propeller through a long extension shaft, with a 37 mm cannon firing through the propeller hub. About 70% of P-63 production went to the Soviet Air Force as Lend-Lease aid; the U.S. Army Air Forces flew the type only as a target-aircraft conversion (RP-63) for B-29 gunner training.

The P-63 added two-stage supercharging (something the P-39 critically lacked) and an enlarged airframe with redesigned wing aerofoil. Maximum speed 410 mph at 25,000 ft — a major improvement over the P-39's 367 mph. Service ceiling 43,000 ft. Armament: one 37 mm M10 cannon plus four .50-cal Browning machine guns (two cowl-mounted synchronised, two in wing pods). The two-stage supercharger gave the P-63 the high-altitude performance the P-39 had lacked, but Allison engine reliability problems and accumulated production-line teething issues meant the P-63 was never widely adopted by the USAAF.

Soviet P-63s arrived in 1944 in large numbers — 2,397 delivered through war's end, plus a final 1944-1945 batch of ferries from the Alaska-Siberia ferry route. The Soviet Air Force used the P-63 in air-defence and air-superiority roles, including some accounts of 1945 combat against late-war Luftwaffe formations. After the German surrender Soviet P-63s saw limited combat against Japanese forces in the August 1945 Soviet-Japanese War, the only direct combat between Soviet-flown P-63s and Japanese aircraft.

The U.S. Army Air Forces converted 332 P-63s to RP-63A/RP-63C target-aircraft configuration with armoured airframes and frangible-bullet armament-detection systems for B-29 gunner training. About 7 P-63 airframes survive in 2026, including airworthy examples at Planes of Fame (Chino, California) and the Commemorative Air Force.

For Kids — a shorter, friendlier version

The Bell P-63 Kingcobra was a fighter plane built in America during World War Two. Bell Aircraft made 3,303 of them between 1942 and 1945. It was bigger and more powerful than its older cousin, the P-39 Airacobra.

The Kingcobra had a cool and unusual design. Its engine sat in the middle of the plane instead of the front. A long shaft connected the engine to the propeller. A cannon fired straight through the propeller hub, plus four machine guns added extra firepower.

This plane could fly faster than 410 miles per hour at high altitude. That is faster than most cars ever dream of going! It could also climb higher than 43,000 feet, which is higher than most clouds.

About 70 out of every 100 Kingcobras built were sent to the Soviet Air Force as friendly aid. The American air forces used some as flying targets to help train gunners on B-29 bombers. These training versions were called RP-63s.

The Kingcobra added a two-stage supercharger that its older brother lacked. This gave it much better performance high up in the sky. It was a real improvement over the earlier P-39 design.

Fun Facts

  • The P-63 Kingcobra could fly faster than 410 miles per hour — faster than a race car by a huge amount!
  • Bell Aircraft built 3,303 Kingcobras in just three years, from 1942 to 1945.
  • About 2,397 Kingcobras were sent to the Soviet Air Force as friendly aid during the war.
  • The engine sat in the middle of the plane, not the front — that was very unusual for a fighter!
  • A cannon fired right through the center of the spinning propeller hub.
  • The Kingcobra could climb higher than 43,000 feet, almost eight miles above the ground.
  • Some Kingcobras were turned into flying targets so B-29 gunners could practice their aim.
  • The Kingcobra was larger than its older brother, the P-39 Airacobra, making it a bigger and tougher plane.

Kids’ Questions

Why was the engine in the middle of the plane?

Putting the engine in the middle helped balance the plane better. A long shaft ran from the engine to the propeller at the front. This design also let a big cannon fire through the propeller hub. It was a very clever but unusual idea.

Why did so many Kingcobras go to the Soviet Air Force?

America sent planes and supplies to friendly countries to help them fight in the war. This program was called Lend-Lease. About 70 out of every 100 Kingcobras built were sent to Soviet pilots. American forces ended up using only a few themselves.

What is a supercharger and why did it matter?

A supercharger pushes more air into the engine so it can work harder at high altitudes. Without one, engines get weak high up where the air is thin. The Kingcobra had a two-stage supercharger that its older brother lacked. This let it fly fast and high much better than before.

Variants

P-63A / C / D / E
Standard production variants. About 1,725 P-63A + 1,227 P-63C + ~50 P-63D/E built. All shared the Allison V-1710-93 / V-1710-117 two-stage supercharged engine.
RP-63A / RP-63C (manned target)
USAAF target-aircraft conversion for B-29 gunner training. Heavily-armoured airframe, frangible-bullet detection lights flashed when hit. About 332 converted from production P-63s.

Notable Operators

Soviet Air Force
Largest user. 2,397 P-63s delivered under Lend-Lease 1944-1945. Used in air-superiority and ground-attack roles. Saw combat against Japanese aircraft in the August 1945 Soviet-Japanese War in Manchuria.
U.S. Army Air Forces
Operated 332 RP-63A/RP-63C target conversions for B-29 gunner training. Did not field combat-capable P-63s; the type was outranked by P-47 and P-51 in production priority.
Free French Air Force
About 300 P-63s delivered to Free French units in 1945. Served briefly in occupation duty 1945-1946; replaced by P-47s and other types thereafter.

Frequently Asked Questions

How is the P-63 different from the P-39?

The P-63 has a two-stage supercharged Allison V-1710 engine (vs. the P-39's single-stage), giving it strong high-altitude performance the P-39 lacked. The airframe is larger with a redesigned wing aerofoil. Maximum speed 410 mph (vs. P-39's 367 mph). The mid-fuselage engine layout, 37 mm cannon, and tricycle landing gear all carry over from the P-39 design.

Why didn't the U.S. Army Air Forces use the P-63 as a fighter?

By 1944 when the P-63 was production-ready, the USAAF had P-47 Thunderbolts and P-51 Mustangs in volume production with proven combat records. The P-63's mid-engine layout had recurring CG issues; the Allison engine had reliability problems compared with Pratt & Whitney R-2800 (P-47) or Packard Merlin (P-51). USAAF priorities sent P-63 production to Soviet Lend-Lease and to RP-63 target-aircraft conversions instead.

Did P-63s fight Japanese aircraft?

Yes — Soviet P-63s engaged Japanese aircraft during the August 1945 Soviet-Japanese War in Manchuria, the only direct combat the type saw against Japanese forces. Specific kill totals are not well-documented; the war lasted only 11 days before Japan's surrender.

How many P-63s were built?

3,303 airframes between 1942 and 1945. About 2,397 went to Soviet Lend-Lease, ~300 to Free French, ~332 RP-63 USAAF target conversions, and the balance to U.S. training squadrons.

What was the RP-63 'Pinball'?

USAAF target-aircraft conversions of the P-63 for B-29 gunner training. The aircraft was heavily armoured to absorb fire from frangible bullets fired by trainee gunners; lights flashed inside the cockpit when hits were detected. About 332 RP-63A/RP-63C airframes converted between 1944 and 1945. The 'Pinball' nickname came from the flashing-light hit indicators.

Sources

See Also