Chizhevski_BOK-5 Knowpia

Crew: 1
Length: 4.365 m (14 ft 4 in)
Wingspan: 9.86 m (32 ft 4.25 in)
Wing area: 23.15 m 2 (249 sq ft)
Empty weight: 596 kg (1,314 lb)
Gross weight: 764 kg (1,684 lb)
Powerplant: 1 × M-11 5-cyl radial , 74.6 kW (100 hp)

BOK-5
Role	Tail-less research aircraft
National origin	USSR
Manufacturer	BOK
First flight	summer 1937
Number built	1

The BOK-5 (Russian: БОК-5) was a tail-less research aircraft designed and built in the USSR from 1937, by the Byuro Osobykh Konstrooktsiy (bureau of special design) (Russian: Бюро особых конструкций (БОК)).

Development edit

The dural and fabric BOK-5 was a single-engined tail-less monoplane used to develop trailing edge controls for tail-less aircraft. The aircraft had a low aspect ratio moderately tapered wing with the fixed tail-wheel undercarriage, single M-11 engine, pilots cockpit all accommodated by the central nacelle which faired into an integral fin, with rudder, at the rear. The trailing edges were each divided into three with elevators inboard, flaps in the middle and ailerons outboard, with all controls inter-connected as required for the test being carried out (sometimes termed 'Flailevators' although this is usually used for single surfaces performing all three control tasks, not separate surfaces with control mixing). Flight trials were carried out by Stefanovskii and Nyukhtikov from the summer of 1937.