LaGG-3/2 VRD

Purpose: To investigate the use of ramjets to boost fighter performance.

Design Bureau: The OKB of Lavochkin, Gorbunov and Gudkov (LaGG).

Unknown to the outside world, the Soviet Union was the pioneer of ramjet propulsion. Such engines are essentially simple ducts, with air rammed in at the front inlet, slowed in an expanding diffuser, mixed with burning
fuel and expelled at high speed through a rear converging section and nozzle. In 1939 M M Bondaryuk, at NIl-GVF OKB-3 (civil air fleet research construction bureau No 3) first ran an experimental subsonic ramjet. In Au­gust 1942 a pair of much further developed versions were attached under the wings of LaGG-3 fighter No 31213173 and tested in the air from 5th August. Test pilot Captain Mishenko made 14 flights. Results were indif­
ferent, but provided a background of data for later ramjet work, collated by M V Keldysh.

The LaGG-3 was a mass-produced fighter of all-wood construction, powered by an M – 105PF engine. The first Bondaryuk ramjets to fly were designated VRD-1, and were tested in two forms. The original was a plain steel duct with a diameter of 140mm (51/2in), length of 2,150mm (7ft1/2in)and weight of 16kg (35.31b). The boosted (forsirovannyi) version had a diameter of 170mm (6%in) and length of 1,900mm (6ft Sin), but weighed the same. Fuel from the three main aircraft tanks was supplied by a special BNK-10 pump with a proportioner to supply both ramjets equally.

Results were sufficiently interesting to jus­tify further work, starting with the VRD (or PVRD) 430 (see page 89). In parallel Merkulov was developing the DM-4 and similar ramjets, tested on the I-153 and I-207.

Dimensions

Span 9.81 m 32 ft 2 in

Length 8.82 m 28 ft m in

Wing area 17.62m2 189.7ft2

Weight and performance not recorded.