Soon after the end of World War I, submarine and aircraft technology was very mature, and these two scientific and technological products had their own duties, one flew in the sky and the other dived in the water, but there was no shortage of brain-opening people in this world, and many designers had tried to combine them to develop a diving aircraft that could both fly and submerge, and if it could be used in the military field, it might be a great success.
However, this idea is not easy to implement, after all, air and water are different media, and the principle of operation of airplanes and submarines is completely different, so there has been no real workable design for a long time. In 1962, North American Airlines was named Donald. Reed's engineers decided to give it a try, and he built a submersible plane out of discarded aircraft parts, called the RFS-1 "Reed Flying Submarine".
The RFS-1 is a two-seater aircraft with an elongated fuselage, the fuselage part is like a submarine hull, with two pontoons side by side under the fuselage to allow the aircraft to float on the water, and the back of the fuselage has a raised structure like a submarine bridge, and its main role is to support a 65 hp Lycoming 4-cylinder engine and propeller propellers. The performance of the RFS-1 is not good, but it verifies the technical possibilities of the diving aircraft, due to the heavy body and weak power, it only reaches a flight altitude of 25 meters in flight, the propellers need to be manually removed before diving, the engine is sealed with rubber equipment, the pilot wears a scuba ride, the RFS-1 is powered by a battery under water, propelled by a 1 horsepower motor, and can dive about 35 meters deep.
The RFS-1 proved that aircraft could be combined with submarines, but it did not attract the attention of the military because it had little practical military value. Around the same time, the U.S. Navy awarded a contract to Convair to develop an anti-submarine diving aircraft, which could fly in the air to reconnoiter the location of enemy submarines and surface ships, land on the surface and then dive into the water to fight after discovering targets, and it was envisaged that it would mainly be used to destroy shipping in the special geographical environment of the Baltic Sea, the Black Sea, and the Caspian Sea.
The military's standards are not too harsh, requiring the aircraft to be able to perform in level 2 sea conditions (wave height of about 0.).5 meters, wind force 2), the aircraft cruising speed of about 350 kilometers per hour, the maximum flight altitude of 2500 meters, the underwater speed of 10 knots, the maximum diving depth of 23 meters, the endurance of 10 hours.
Convair abandoned the seaplane design with pontoons, but adopted a narrow-body flying boat design, the fuselage was divided into multiple compartments, it used trapezoidal wings and double vertical tails, ballast water tanks were set in the fuselage and wings, and the aircraft surface flight power was 3 turbojet engines, two engine nacelles were installed above the wings, and the other was in the back-to-back position of the aircraft, and the engine air intake and tail nozzle still needed to be waterproof and sealed before diving. The aircraft is still powered underwater by batteries, and the propellers are propellered by electric motors.
Convair's dive aircraft can carry two crew members, but they have a sealed cabin, which does not need to carry alveoli in the water, the cabin where the crew is located can be separated from the body as a whole, it has a parachute to parachute in the air, and when underwater, it relies on its own buoyancy to float to the surface, which is a means of escape for the crew. The aircraft had a payload of 500 to 1500 pounds, and it was planned to use torpedoes or mines as an attack**, the payload was too low for it to carry heavy **.
Convair tested a scaled-down model in the '60s and found it entirely viable, but the military had mixed views on the submersible, with many arguing that it would not improve the Navy's combat capabilities and that it was a wasteful project, which eventually led to the termination of the program in 1965.