Belyaev developed the twin boom idea of his "batwing" BP-2 glider into the DB-LK, which had two short fuselages either side of a very long wing centre section, with the outer wing sections swept forward 5 deg 42 min, tapering at 7:1 out to raked back tips. A large fin and rudder on a short central boom, carried a small tailplane with very large elevators The airframe was of light alloy stressed skin construction with five spar wings covered with sheet aluminium alloy. Each fuselage pod carried a single Tumansky M-88 engine (replaced with 950 h.p. Tumansky M-87bs for testing) in a long chord cowling, driving a three-bladed VISh-23Dp propellers, as well as a pilot/navigator cockpit and radio operator/gunner station in each of the extensively glazed tail-cones. The outer wings had slats, ailerons and the raked tips also had small ailerons. The retractable undercarriage consisted of single main legs in the fuselage pods aft of the engines and a tail-wheel in the base of the fin.
The M-87b engines meant that the plane could only achieve an unladen speed of 303 mph instead of the projected performance of 340 mph, which was not an advantage over current designs. The navigator and rear crew positions were very cramped, and visibility for the navigator and pilot were poor. In addition to its other faults, the crew compartments had a tendency to fill with exhaust fumes, which would have resulted in the crew having to wear oxygen masks. Due to these issues production was not authorized, but the Soviet Air Force was intrigued by the overall design and looked into having the DB-LK redesigned as a dive bomber, but nothing came of this idea. The plane was likely destroyed during World War II.

credits to Wikipedia for this
full article at https://en.wikipedia.org/wiki/Belyayev_DB-LK