BEACH-7

After successful tests of the BICH-3, Cheranovsky during the years 1927–28 was engaged in the design of the twin-engine bomber BICH-5 with BMW VI engines and the blowing in the wind tunnel of various versions of aircraft models made according to the “flying wing” scheme. And in 1929, using the results of the work performed, he built the BEACH-7 aircraft, which was a further development of BEACH-3 ^[1] .

The new car, compared to the BICH-3, was a two-seater with separate open cabins, had a Bristol Lucifer piston engine with a capacity of 100 hp. and a half times the large wing area. The rudders were at the wingtips, without keels. The chassis is one -wheeled, with crutches in the tail and at the ends of the wings. Mainly due to an unsuccessful landing gear design and, as a result, difficult take-off, the aircraft was never raised into the air ^[1] .

BEACH-7A

After a number of improvements, including a change in chassis from one-wheeled to more traditional - a two-wheeled pyramidal scheme with a crutch; the installation of a closed cabin tapering to the rear with the transition to the keel , which allowed to improve the controllability of the aircraft due to more efficient airflow of the rudder with a jet of air from the propeller. The wing mechanization consisted of flaps (two on the wing), which could work both together and separately - in this case, the latter served as ailerons ^[2] .

Tests of the aircraft conducted N.P. Blagin . The first flights revealed a disadvantage in which, due to the relatively large area of ​​the elevators, there was increased pressure on the control handle, which was corrected by installing flaps bent down on the trailing edge. BICH-7A showed good stability in all flight modes, had no tendency to lose speed on turns and overall control of the machine, according to the pilots flying on it, was no different from the control of normal planes.

The logical development of the BICH-7A design was the BOK-5 aircraft designed by V. A. Chizhevsky in the Bureau of Special Structures ^[2] .

Data source: V. B. Shavrov “The history of aircraft designs in the USSR until 1938” ^[1]

Specifications

• Crew : 2
• Length : 4.7 m
• Wing span : 12.2 m
• Height :
• Wing area: 30 m²
• Empty weight: 627 kg
• Normal take-off weight: 880 kg
• The mass of fuel in internal tanks: 93 kg (including oil )
• Powerplant : 1 × PD Bristol Lucifer
• Engine power: 1 × 100 hp (1 × 75 kW)

Flight characteristics

• Maximum speed: 165 km / h (near the ground)
• Wing load: 29.3 kg / m²

• BOK-5