Syemyon Alekseyevich Lavochkin worked in numerous brigades and groups, making detailed study of delta plastic-impregnated birch laminates. Convinced such material of great strategic importance, in releasing aluminium, obtained permission to build delta fighter, forming OKB-301 with V.P. Gorbunov and M.I. Gudkov and producing I-22 (30 March 1940). About 100 built as LaGG-1. Frantic improvement led to LaGG-3, total by August 1942 6,528 plus about 90 prototypes and incomplete (some lost in snowdrifts!). Switch to M-82 (ASh-82) radial engine resulted in greatly improved LaG-5 (March 1942), leading to La-5 built in several versions (about 9,920). In turn led to outstanding La-7, -9 and -11 with increasing switch to metal airframe. First jet fighter La-150 (17 September 1946) led via other prototypes to production La-15 (500) and La-15UTI trainer (500), and La-176 (supersonic in dive 26 December 1948) to La-200 2-seat night fighters, culminating in giant Mach 1.88 La-250 interceptor (16 July 1956). Lavochkin died 9 June 1960, bureau closed.