The P-39 was the principle American fighter when WWII broke out

The P-39 was the principle American fighter when WWII broke out

When the United States entered World War II, the Bell P-39 was its primary fighter plane. By war’s end, nearly 10,000 had been produced in nearly 48 variants, making the “Airacobra” one of Bell’s most successful aircraft ever.

As American technology advanced, and newer, faster, better aircraft were produced for the USAAF, the P-39 continued to dominate in the Soviet Air Force, where it scored more total kills than any other American plane throughout the war. P-39s also served in the Royal Australian Air Force to counter Japanese air raids. The Italian Co-Belligerent Air Force received 170 surplus P-39s once Italy sided with the Allies.

The P-39 is a great-looking airplane, armed to the teeth, but its climb rate, speed, maneuverability and performance at altitude paled in comparison to existing British fighters like the Spitfire. That might have been it for the “Airacobra” if not for the lend-lease program that sent thousands of the fighters to Soviet Union.


In 1937, the United States Army Air Corps (Named United States Army Air Forces after 1941) recognized the need for a new fighter with more armament and the ability to engage hostile targets at high altitude.

At the time, the military was referring to this as an “interceptor,” but it was really just a heavy pursuit fighter.

Bell did not have much experience in fighter design, (of course, not many companies did in the 1930s) and its previous attempt was the faulty YFN-1 Airacuda. But some of the design elements translated well, like the liquid-cooled Allison V-12 engine mounted in the middle of the fuselage, behind the cockpit. The propeller was driven by a drive-shaft passed from the engine, under the cockpit floor.

This freed up room for a 20 or, more commonly, a 37 mm M4 cannon fired right through the center of the propeller hub. The P-39 also had two .50 cal machine guns and four .30 cal guns, and it could carry 500 lbs of bombs.

The “Airacobra” ended up being one of the first examples of a military airplane built around its primary weapon. The 37 mm cannon fired a 1.3 lb armor piercing projectile.

What happened next would change the course of the air war. The Royal Air Force ordered about 400 P-39s in September 1940 and about 300 more later on, but Britain quickly rejected the P-39 as its rate of climb and performance at altitude was inadequate for the European Theatre. Only 80 P-39s would see RAF action. The RAF transferred 200 fighters to the Soviet Union, and another 200 were diverted to the US Fifth Air Force in Australia immediately after the attack on Pearl Harbor.

The P-39 was very useful in bombing and ground attack in the Pacific, and it broke about even with 80 kills of Japanese aircraft with about the same number lost.

It was on the Eastern Front where the “Airacobra” proved most effective. The Soviets removed some of the armament from most its P-39s to improve its maneuverability. The P-39 was very effective against a variety of Luftwaffe aircraft, and several Soviet aces earned their designation in an “Airacobra.” A total of 4,719 P-39s were sent to the Soviet Union, with about 22 percent lost in combat.

Bell also built the XFL-1 “Airabonita,” a derivative of the P-39, which lost out to the F4U Corsair as a naval fighter.



Crew: One
Length: 30 ft 2 in
Wingspan: 34 ft 0 in
Height: 12 ft 5 in
Empty weight: 5,347 lb
Max. takeoff weight: 8,400 lb
Engine: One Allison V-1710-85 liquid-cooled V-12, 1,200 hp


Maximum speed: 376 mph
Range: 525 miles on internal fuel
Ceiling: 35,000 ft



  • 1 x 20mm or 37 mm M4 cannon with 30 rounds HE or AP
  • 2 x .50 cal machine guns. 200 rounds per nose-gun
  • 4 x .30 cal machine guns, wing mounted. 300 per wing-pod


  • Up to 500 lb (230 kg) of bombs externally

Essential Reading

Warbird Tech Vol. 17” is a good read that details some of the technical issues of the plane as well as the Russian exports.

I particularly like “Airacobra Advantage: The Flying Cannon” by Rick Mitchell as well. It tells the story of this “unsung hero” starting with its failures in the RAF and emergence in the Soviet Union.

If you’re particularly interested in the lend-lease program, try “Soviet Lend-Lease Fighter Aces of World War 2” by George Mellinger. The book discusses how the US and Britain rushed to re-equip the Soviet Air Force, which had plenty of pilots but no aircraft to fly by the end of 1941.

Online Resources:

Photo Gallery