My favorite Soviet fighter of the World War II Era is the Lavochkin La-5.
Ivan Kozedub, leading Allied Ace of World War II, got all 62 of his kills flying Lavochkin fighters. Below 15,000 feet the La-5 could out climb and out maneuver both of the main German fighter aircraft: the Bf 109 and the Fw 190. Armed with two 20 mm cannon in the cowling and 200 rounds per gun, the La-5’s weight of fire was 3.88 pounds per second. The all around vision canopy provided the La-5 an advantage over its lineal predecessors.
The first example of the LaGG-1, designed by Lavochkin, Gorbunov, and Gudkov, was completed in March 1940. It was built of plywood with birch veneer and powered by a Klimov M-105 engine of 1,050 horsepower at altitude. The first production machine, the LaGG-3, went into service on the Baltic Front with the 19th Fighter Air Regiment and the 157th Fighter Air Regiment. It first saw action during the defense of the Baltic Fleet on 21 September, 1941. More than 6,000 LaGG-3s were built.
The Klimov M-105 engine, used in Yak and MiG fighters, was in high demand. The Yak-7B had a better performance than the LaGG-3 and production in Aircraft Plant 21 was about to be shifted to that aircraft. The surplus of Schvetsov M-82 engine, which powered only the Sukhoi Su-2 light bomber, made a conversion of the Lavochkin fighter to that power plant attractive. The redesign of the LaGG-3 to the new power plant was a complicated process requiring many changes to the fuselage to accommodate the larger diameter of the M-82 and the change in armament made necessary because the solid drive shaft of the M-82 would not accommodate an engine mounted cannon.
The first ten LaG-5 fighters assembled in June 1942 had numerous problems but the transition to full scale production was accomplished without a reduction in delivery rate to the VVS. Their first combats took place in August 1942 during the defense of Stalingrad. The new aircraft proved itself in combat. The 18 cylinder radial engine provided protection to the pilots in head-on attacks and sustained damage and continued to operate, unlike the in-line engine. Many pilots flew the aircraft with the canopy open, the cowling side flaps open, and the tailwheel extended reducing its speed by 30 to 40 kilometers per hour. Demands were made to reduce the weight of the aircraft with an eye to improving its performance. Lightening of the airframe increased maximum speed 18 to 20 kilometers per hour. Designer Semyon Lavochkin continued to improve the aircraft aerodynamically. Engine updating and weight reduction improved the maximum speed and combat capability.
The La-5 remained in production even after its replacement, the La-7, went into production. An excess of wooden wings at the factory in Gorkii caused the La-5 to remain in production until October 1944. The La-7 changes included a metal single spar wing as opposed to the wooden two spar wing of the La-5. Other changes included a redesigned propeller, and uprated M-82 engine, and an armament increase to three 20 mm cannon. La-7 production began in the Moscow plant in June 1944.
Sources: Soviet Combat Aircraft of the Second World War, Yefim Gordon and Dmitri Khazanov, Midland Publishing Limited, Leicester, England, 1998
The Lavochkin La-5 & 7, Witold Liss, Profile Publications, Surrey England, 1967