Flying submarine

A flying submarine is a craft able both to fly or travel under water.

The Soviet Union tried to develop a flying submarine during World War II. The design could have operated at 150 knots in the air and 3 knots in the water. Metal plates sealed the engines shut. The design never "got off the ground."&lt;ref&gt;Russian Flying Submarine Unknown, Date Unknown (accessed 21 January 2007)&lt;/ref&gt;

In 1961 Donald Reid designed and built a single-seat craft (32.83 ft length) capable of flight and underwater movement. A 65 hp (48 kW) engine mounted on a pylon provided propulsion for flight; a 1 hp electric motor in the tail provided underwater propulsion. The pilot used an aqualung for breathing underwater. The first full cycle flight [underwater at 6.5 feet (2 m.) depth, airborne at 33 ft. (10 m.) altitude] was demonstrated on 9 June 1964.&lt;ref&gt;http://www.aerofiles.com/_ra.html see Reid, Ashbury Park NJ (subheading)&lt;/ref&gt;

The US Navy is reportedly looking at the Lockheed Martin Cormorant, a drone aircraft launched from a submarine. On launching it floats to the surface and after flight it is retrieved from the water surface; it cannot travel directedly underwater.

Flying subs in fiction
A wide variety of flying submersible craft can be found in X-COM: Terror from the Deep.

A flying submarine was a feature in:
 * Voyage to the Bottom of the Sea (TV series)
 * The Japanese Toho Studios film Atragon.
 * Sky Captain and the World of Tomorrow
 * The Incredibles