Lavochkin La-7

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. This embodied the results of a TsAGI wind tunnel programme aimed at defining areas in which the basic La-5FN could be aerodynamically improved. Incorporating the modified wing structure (metal spars replacing the wooden box spars) intended for application to the definitive La-5FN (but not to be introduced on that fighter until the late spring of 1944), 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. The intended armament comprised three 20mm Berezina B-20 cannon, but while this armament was installed in aircraft built at Yaroslavl, those built at Moscow reverted to the twin ShVAK cannon of the La-5FN. Variants included the tandem two-seat La-7UTI trainer, the La-7TK with a pair of TK-3 turbo-superchargers, and the rocket-boosted La-7R. The La-7TK was test flown in July- August 1944, but was destroyed when a turbo-supercharger exploded. Another example was fitted with the 2000hp ASh-71TK, trials soon being discontinued owing to the erratic behaviour of this engine's turbosuperchargers.

The La-7R, of which two prototypes were tested, was fitted in the rear fuselage with an RD-lKhZ liquid rocket motor of 300kg thrust, the first prototype being destroyed during the initial take-off run in October 1944. Flight testing of the second prototype continued until February 1945, and a further example - a conversion of one of the original prototype airframes and therefore referred to as the La-120R - entered test in January 1945, this having an improved rocket motor and local airframe structural changes. Testing of the La-120R continued until late 1946.

A total of 5,753 La-7s had been manufactured when production ended in 1946.

3-View

A three-view drawing (1653 x 1193)