The Kalinin K-12 was a scaled-down three-seat prototype proof-of-concept aircraft for a far larger tailless bomber. Also known as the BS-2 or the Zhar-Ptitsa (Firebird), this pre-WW2 Russian design is credited to K.A. Kalinin.
Design began at Voronezh in 1934. A glider of similar lines, with a 29 ft. 6½ in. (9.0 m) span made a hundred flights before the K-12 was proceeded with. The K-12 flew in autumn 1936 and was demonstrated at Tushino on 18th August 1937, in a garish colour scheme representing a bird. The aircraft was of welded steel-tube construction with fabric covering, and was powered by two 480 hp M-22 radial engines. It featured dummy nose and tail turrets.
Work on the scaled-up K-12 ended when Kalinin was arrested in spring 1938 and his design bureau disbanded.
The K-12 had a 59 ft. 0.66 in. (18 m.) span, a 26 ft. 3 in. (8.0 m.) length and a loaded weight of 9,259 lb. (4200 kg.).
It achieved a maximum speed of 149 mph (240 km/h) at 9,840 ft (3000 m.), and had a range of 435 mls (700 km.).
Source: Unreal Aircraft