The aerial torpedo, airborne torpedo or air-dropped torpedo is a naval weapon, the torpedo, designed to be dropped into water from an aircraft (fixed-wing aircraft or helicopter) after which it propels itself to the target. First used in World War I, air-dropped torpedoes were used extensively in World War II, and remain in limited use today. Aerial torpedoes are generally smaller and lighter than submarine- and surface-launched torpedoes.
Historically, the term "aerial torpedo" was used to describe flying bombs and pilotless drone aircraft intended as weapons, the precursor to modern cruise missiles. Today, the term refers primarily to water-borne torpedoes launched from the air.
A successful aerial launched torpedo design needs to account for
The Japanese Type 91 torpedo used aerodynamic tail stabilizers in the air. These stabilizers (introduced in 1936) were shed off when it entered the water. And a new control system (introduced in 1941) stabilized the rolling motion by countersteering both in the air and the water. The Type 91 torpedo could be released at speed of 180 knots (333 km/h) from 20 m (66 ft) into shallow water but also at 204 knots (the Nakajima B5N2's maximum speed) into choppy waves of a rather heavy sea.