The LaGG-3 was essentially the series production version of the LaGG-1 with a revised outer wing incorporating fuel tanks, and an armament of one 20mm and two 7.62mm weapons.
LaGG-3 deliveries commenced in the spring of 1941, initially with the M-105P engine, but, from late in the year, with the M-105PF affording 1260hp at 800m. Provision was later made to replace one or both machine guns by weapons of 12.7mm calibre, the 20mm hub-mounted cannon being replaced by one of 23mm calibre in some cases, and a pair of 12.7mm underwing guns was sometimes fitted. Production of the LaGG-3 was completed in the late summer of 1942 with a total of 6,528 built.
Adaptation of the basic LaGG-3 airframe for a 14- cylinder two-row radial Shvetsov M-82 engine without major redesign of fundamental components resulted in the La-5 (examples converted from existing LaGG-3 airframes on the production line sometimes being referred to as LaGG-5s).
Late in 1942, the improved M-82F engine became available, producing 1650hp at 1650m, aircraft fitted with this engine being designated La-5F, and, from early 1943, fuel tankage was revised. From late March 1943, the fuel injection M-82FN engine offering 1850hp for take-off replaced the carburettor-equipped M-82F, and with this power plant the fighter became the La-5FN. When the La-5 was withdrawn from production late in 1944, a total of 9,920 aircraft of this type (including La-5UTI two-seat trainers) had been built.
The ultimate refinement of the basic La-5 rather than a new design, the La-7 was developed from the autumn of 1943 under the bureau designation of La-120. Incorporating the modified wing structure, a revised inboard wing leading edge and an entirely new cowling for the Shvetsov M-82FN engine, the La-120 was first flown in November 1943. In the following spring it entered production as the La-7.
A total of 5,753 La-7s had been manufactured when production ended in 1946.
The La-9 retained the ASh-82FN radial of the preceding fighters, but provision was made for a quartet of 23mm NS-23 cannon. Series production was authorised in November 1946.
