Air torpedo

An Air Torpedo is the universal name in the war for a type of elongated trench mortar bomb, fitted with balancing planes or "fins," which gave the projectile something of the appearance of a torpedo. Torpedoes contain, and are actuated by, self-propelling mechanism. The naval service torpedo was dropped by aeroplanes. Its course and depth for running below the surface are set before being dropped. Employed by the "Dart" type of sea-plane, the RN "Torpedo", as a word, was the name given to a species of fish which defends itself by giving an aggressor and electric shock. (From torpere, to benumb).