An
aerial torpedo,
airborne torpedo or
air-dropped torpedo is a naval weapon, a
torpedo, that an aircraft—
fixed-wing aircraft or
helicopter—drops in the water, after which it self-propels to the target. First used in
World War I, air-dropped torpedoes were used extensively in
World War II, and remain in limited use. Aerial torpedoes are generally smaller and lighter than submarine- and surface-launched torpedoes.