Lockheed CL-865 submersible aircraft

In 1964, Lockheed responded to a US Navy RFP for a flying submersible anti-submarine-warfare craft. Two of the designs studied were the CL-865-1 and CL-865-2, bot of which were more “submersible aircraft” than “flying submarines.” Both featured long-span, straight, high aspect ratio wings, a two-man crew, a single T56 turboshaft engines and hydroski landing gear. The -1 connected the T56 to a single propellor mounted on a pylon well above the fuselage (in a layout reminiscent of a n umber of motorized sailplanes), while the -2 connect the turboshaft to two ducted fans. The -2 was the more aggressive of the two designs (though there were apparently other even more advanced concepts), using wings that would fold back to reduce underwater drag and a water augmented rocket for takeoff assist. Both designs would have met the design requirements of:

1) cruise altitude: 2500 feet

2) cruise speed: 225 knots

3) flight radius: 500 nautical miles

4) submarine endurance: 10 hours

5) Maximum depth: 75 feet

6) Payload: 1500 pounds