There have been efforts, some more fruitful than others, to pilot fixed-wing aircraft, mostly floatplanes, from submarines since the dawn of naval aviation. The concept of aircraft-carrying submarines was practically dead by the time the helicopter became a well-established feature of air warfare, shortly after World War II. However, during a fascinating series of trials onboard the USS Sealion in the mid-1950s, the US Navy managed to operate at least one helicopter from a submarine. Specifically, they used the Balao class submarine, a veteran of the Pacific War, in testing helicopters filled with Marines.
The Crossroads of Special Operations