In 1934 cadet VMIU them. Dzerzhinsky B.P.Ushakov presented schematic design flying submarine (LPL), which was later reworked and presented in several different ways to determine the stability and loads on the structural elements of the machine.
In April 1936, in a review of Captain 1st Rank Surin pointed out that the idea is fascinating and deserves Ushakov undeniable realization. A few months later, in July, polueskizny project considered in LPL Research Military Committee (NIVKI) and received generally positive reviews, which contained three additional Fri, one of which said: «… The development project is best to continue to identify the reality of his implementation by respective production calculations and relevant laboratory tests … «In the midst of the signatories were the chief of Military Engineer Nyvka Grigaytis rank 1 and the chief of the department’s flagship strategy combat weapons grade 2 Dr. Goncharov.
In 1937, the topic was included in the plan of «B» Nyvka, but after reviewing it, it was very typical of long abandoned. All forthcoming development was conducted engineer of «B» military technician 1st rank B.P.Ushakovym while off duty.
January 10, 1938 Second Department held Nyvka consideration and sketches the main tactical and technical parts LPL prepared creator That still is a project? Flying submarine designed to attack enemy ships on the high seas and in the waters of naval bases protected by minefields and booms. Shallow underwater speed and limited progress in store under water LPL is not an obstacle, because in the absence of goals in this square (the area acts) boat could itself seek out the enemy. Defining its course from the air, she sat down on the horizon, which excluded the possibility of its early detection, and plunged into strips ship ways. Until the emergence of goal salvo at LPL remained at a depth in a stable position without expending unnecessary energy moves.
In the case of allowable deviation equation enemy from the strip rate LPL was a rapprochement with him, and at very bolshennom deviation boat missed its target over the horizon, then floated, soared again and ready to attack.
Probable repetition approach goal was regarded as one of the significant advantages of underwater torpedo air before the classic submarines. In particular, effective action should have been flying submarine in the group, because theoretically three such apparatus made in the way of enemy impassable barrier to 9 miles wide. LPL could seep into the black during the day in the harbor and the ports of the enemy, dive, and funny day to monitor, direction finding hidden fairways and comfortable case of storm. The design LPL envisaged autonomous 6 compartments, 3 of which were placed the aircraft engines AM-34 rated at 1,000 hp each. They were equipped with superchargers, admits speeding at takeoff and 1200 hp Fourth compartment was habitable, calculated on a team of 3 persons. He was carried from the same control of the ship underwater. In fifth was battery compartment, in the sixth — rowing motor capacity of 10 liters,. Strong body LPL is a cylindrical riveted construction diameter of 1.4 m from duralumin, 6 mm wide. Besides strong compartments boat had pilot’s cabin light wet type, which, when filled with water immersion, With all this flight instruments battened down in a special shaft.
Trim the wings and tail supposed to perform steel and floats from duralumin. Etielementy structures were not designed for external pressure inflated because when immersed flooded with sea water, flows by gravity through the scuppers (holes for water drainage). Fuel (gasoline) and oil stored in special rubber tanks, located in the center section. When submerged inlet and outlet mains water cooling system of aircraft engines overlap, which excluded their damage under the pressure of seawater. To protect the body against corrosion provided for coloring and varnishing of his skin. Torpedoes were placed under the wing panels on special holders. The project needed a boat load was 44.5% of the total flying weight machine that was commonplace for cars languid type.
Dipping process included four steps: zadraivanie motor departments, overlapping the water in the radiators, the transfer of control and underwater transition from the cabin crew in the living compartment (central control).
Tactical flight LPL properties:
Crew. — 3
Takeoff weight, kg — 15 000
Airspeed, knots. (Km / h) — 100 (-200)
Range, km — 800
Ceiling, m — 2500
Number and type of aircraft engines — 3xAM-34
Power at takeoff, hp — 3×1200
Max. ext. excitement during takeoff / landing and dive points — 4-5
Ck U-Th, knots — 2-3
Depth, m — 45
Supplies running underwater miles — 5-6
Underwater autonomy, h — 48
Power propeller motor hp — 10
Dive time, min — 1.5
Duration ascent min — 1.8
— 18-inch. torpedo units. — 2
— coaxial machine gun, pc. — 2