Bereznayak-Isayev Berez-Isa BI
Under the direction of Prof Viktor Bolkhovitinov, with detail design by Aleksandr Beremyak and Alekseilsayev (accounting for the BI of the designa tion). the Berez-Isa BI was the first liquid rocket-engined fighter flown in the USSR. A low-wing monoplane, the BI had a Dushkin D-IA rocket engine in the tail, and this was highly tempermental, its fuel mixture of kerosene and nitric acid being not only dangerous to handle, but also causing corrosion of tanks and fuel lines. The BI was flown initially as a glider on 10 September 1941, the first significant powered flight of 3 minutes 9 seconds, being made by the third prototype on 15 May 1942. Work on 50 pre-production aircraft was started, but halted when a prototype dived into the ground on 27 March 1943 during a low-level high~speed run, killing its pilot. The endurance of the BI was in adequate for operational use, but a two-chamber engine developed by Dushkin to overcome this deficiency with low (cruising) and high (combat) thrust settings was almost double the weight and considered unsuitable. Wind tunnel testing that followed the fatal crash revealed a stability problem that could not be resolved and further development was abandoned. Before this, however, the seventh prototype with a more powerful engine had demonstrated a rate of climb of 4980 m (16,340 ft) per minute.
The third prototype BI was fitted with retractable skis which couldbe interchanged with wheels depending on the ground conditions.
Engine: one 1000-kg (2,205-1b) thrust Dushkin D-IA rocket
Max speed (estimated): 1000 km/h (621 mph) at 5000 m (16,405 ft)
Climb to 10000 m (32,810 ft): 59 seconds
Endurance: 8 to 15 minutes
Empty weight: 958 kg (2,112 lb)
Maximum take-off weight: 1683 kg (3,7 10 lb)
Wing span: 6.48 m (21 ft 3 in)
Length: 6.40 m (21 ft 0 in)
Wing area: 7. 00 sq.m (75.35 sq ft)
Armament: two nose-mounted 20-mm ShVAK cannon