p-39 The P-39 Airacobra (English: P-39 Airacobra) is a fighter designed by the American Bell Aircraft Company. It was active during World War II . The biggest difference in design between the P-39 and other fighter jets of the same period is the location of its engine: the P-39's engine is in the center of the fuselage, behind the pilot, and the propeller in front is driven by a long drive shaft from the engine. drive. The biggest advantage of this design is that the heaviest part of the entire aircraft is placed at the center of gravity of the aircraft, which improves the aircraft's motion performance. Another feature is that unlike the rear tricycle landing gear that was widely used on fighter jets at the time, this model uses a front tricycle landing gear.
The first XP-39 prototype flew for the first time on April 6, 1938. The original design was planned to be equipped with a V-1710-17 liquid-cooled engine and equipped with a General Electric Company turbocharger to perform high-altitude operations. mission single-seat fighter.
Its nose space can also accommodate the large-caliber cannon (37mm), which has become a feature of the P-39's firepower configuration. The performance of the prototype is quite good, reaching a speed of 390 miles per hour at an altitude of 20,000 feet. However, this prototype aircraft was not equipped with any weapons, armor and other avionics equipment required on mass-produced aircraft, so there was a big gap in basic weight with subsequent actual combat-equipped models. However, later the U.S. Army Air Forces (due to insufficient production and certain bureaucratic factors at Wright Field) asked the design department of the Bell Company to delete the turbocharger originally equipped on the aircraft, causing the P-39 to fail at 6,000 feet. The performance above is significantly degraded. Not only that, because the installation of self-sealing fuel tanks will reduce the amount of fuel carried in the aircraft and shorten the time in the air, the performance of the mass-produced P-39 will be very different from the expected performance, and it has even been criticized as a design that is outdated before it is put into service. In addition, In addition, the mid-engine layout also makes the P-39 inconvenient to repair. Many skins need to be removed to repair the engine, which is relatively disadvantageous in maintenance work at frontline airports.
The first mass-produced P-39 was equipped with a 37mm cannon in the nose and two .30 and .50 machine guns . This armed configuration was changed to a 37mm machine gun in the nose in the P-39D model. Cannon and two .50 machine guns, and two .30 machine guns on each side of the wing.
P-39 briefly served as the main force of the U.S. Army Air Forces in the early days of World War II. It was especially stationed at Henderson Airport on Guadalcanal and used to fight the Japanese army. However, it was quickly withdrawn due to poor performance. Positioned on the second line and responsible for training tasks. The United States instead shipped a large number of P-39s to the Soviet Union under the Lend-Lease Act, allowing this aircraft to find another sky in the Soviet battlefield.
Although at first Soviet pilots, like their American counterparts, had many negative comments about the performance of this aircraft, they believed that it could only make up for the insufficient production of Yak-9 and La-5 fighters at that time, and the Soviet officials deliberately lowered the use of foreign aid aircraft on the Soviet battlefield. Performance.
However, because of its very practical and reliable performance in the cold Soviet airspace, the P-39 relied on its innate design to have good maneuverability and solid armor at low altitudes (compared with the German Bf109 and Fw190), and in 1942 The firepower of the highest caliber aerial cannon of fighters at the time, as well as the radio equipment generally lacking in Soviet fighter jets at the time, allowed them to effectively compete with the German Air Force in actual combat (especially low-altitude airspace and frontline tactical air control missions), allowing pilots to have Chance to survive and accumulate experience to gradually be able to defeat the enemy. Not only did it receive considerable praise, it also achieved an excellent shooting record and became the seat aircraft of many Russian ace pilots.
At the end of the war, a total of 9,529 P-39s were shipped from the factory. After deducting losses, 4,789 were shipped to the Soviet Union.
