Made by Bell Aircraft Corporation, the P-39 Airacobra was produced from 1939 until 1944 and it might be called the most controversial US fighter plane of WWII.
It was embraced heartily by the Soviets and equally shunned by both the USAAC and the RAF; it was hounded by myths and falsehoods that added to the controversy to this day.
It was off to an auspicious start when the first unit, the XP-39 was unveiled at Wright Field on April 6, 1939 to the gasps and ahs of the assembled dignitaries.
One could see at first glance the innovations and peculiarities incorporated into Bell's new Airacobra.
The P-39 was the first fighter plane to use a tricycle landing gear configuration, later adopted by all aircraft of all makes.
One feature that didn't catch on was the car-like door by which the pilot entered and exited the cockpit, instead of the usual sliding cockpit canopy.
Basically, the Aircobra was designed around a gun, the Colt M4 37mm cannon.
To make room for the cannon in the nose, the powerplant, an Allison V-1710 was installed mid-fuselage behind the pilot.
It was fitted with a B-5 turbo-supercharger and rated at 1,150 hp.
This was essentially the same engine that was so successful in the P-38 Lightning.
The power was transmitted to the propeller via a drive shaft that ran under the pilot's seat.
The unarmed and unarmored prototype could reach a then stunning speed of over 390 mph and climb to 20,000 ft in five minutes.
This is where the first bad decision was made regarding the P-39, a mistake that would haunt it for all its fighting days.
Despite its admirable performance during test flights, the Wright-Field engineers felt it had too much drag, so to streamline the design the canopy was lowered, the wingspan cut by two feet and the fuselage lengthened by one foot.
Most importantly, the turbo-supercharger inlet was reduced in size and moved from the side of the fuselage to a position directly behind the canopy.
This meant that the turbo-supercharger had to be replaced with a single stage supercharger with the entirely predictable result that the high-altitude performance dropped dramatically as did the maximum speed and rate of climb.
The P-39D was the first mass-produced model in 1941, with all following models being quite similar.
The D-1 temporarily replaced the 37mm cannon with a 20mm cannon.
The P-39D did have an updated Allison engine, which produced an additional 175 hp.
The basic specs of the P-39D were: Max speed of 360 mph at 15,000 ft, Climb to 20,000 in 11.
7 min.
Range: 600 miles at economical cruise, Armament: one 37 mm nose cannon, 2 50 calibre nose guns, 2 30 calibre guns in each wing.
It was a light aircraft with an empty weight of 6,300 lbs and max weight of 9,200 lbs.
The final and most numerous production version was the P-39Q with 4,905 being built.
In summer 1939, the first orders for the P-39 was placed by France, but none were delivered because France fell too quickly to the Germans.
Britain accepted the French order but the RAF pilots hated the Airacobra mainly because of its now poor performance over 20,000 ft and a tendency to spin, with a marked difficulty to recover from a spin.
Also they complained that the M4 cannon had a tendency to jam, but they did concede it was an effective fighter below 15,000 feet.
They eventually returned the aircraft back to USAAC who used them in the early days of the Pacific war, in places like Guadalcanal.
The US pilots had the same complaints as the RAF and were soon requesting transfers to the P-38 squadrons.
In fact there was a standing joke about the P-39; the RAF had renamed the model the P-400 and the story was that a P-400 was a P-39 with a Zero on its tail.
As the P-38 Lightning was phased in, the P-39s were ferried to Russia as part of the Allied assistance to the Eastern front.
Of the 9,585 P-39s built, 4,500 were given to the USSR.
The P-39 was fast gaining the reputation of being the worst fighter plane of WWII.
Here the P-39's luck changed for the better.
The Russian pilots loved the Airacobra, nicknamed it the "Britchik" (Little Shaver, from the Russian slang for strafing - "shaving") and began to have great success with it.
From 1943 until the end of the war, the "Iron Dog" (the official Soviet designation) saw extensive action.
Although the Russian pilots had the same problems with spin recovery, their early problems centered around the use of the radios; for most it was the first aircraft they had flown with radios!They liked its low altitude speed and maneuverability, excellent structural integrity and heavy armament.
Soviet pilots regularly mixed it up with and won over German fighters.
In fact five out of ten of the highest scoring Russian pilots were P-39 jockeys.
Pokryshkin was second with 59 victories, Gulaev was third with 57 and Rechkalov fourth with 56, this with the "worst fighter plane of the war!" It must be said however that the Eastern front was a different kind of war in many ways.
For fighter planes there was no long range, high altitude strategic bombing escort duty, instead it was low-level tactical bombing and dog-fighting which was where the P-39 excelled.
So there you have it.
The P-39 was a failure with the USAAC and the RAF, a howling success with the Soviets.
The experts say it was because the western allies were fighting a different kind of air war than the Russians.
Whatever the reason, it's the saga of a fighter plane that was "different" from the day it first rolled out onto the tarmac in 1939.
Of the number built, 9,558, only 2 are known to be still airworthy.