While rolling down the Soviet/Russian concept plane rabbit hole, I found this beauty.
Ushakov LPL Flying Sub Statistics:
Crew, man. 3
Takeoff mass, kg 15,000
Flight speed, UZ (km/h) 100 (~200)
Flying range, km 800
Ceiling, m 2 500
Quantity and the type of aircraft engines 3 x AM-34
Power...