One approach to obtaining a wide field of fire to destroy bombers from below was that of J. A. Peters, whose three-seat Robey-Peters Gun Carrier of 1916 incorporated nacelles under the top wing, with a Davis six-pounder in each (only in the starboard nacelle here). The sole example, 9498, crashed on its first flight and no more were built.
One of the least-known of British warplanes was surely the Robey-Peters Gun-carrier, designed to have an American Davis recoilless gun in the nacelle on the starboard wing, and a Lewis gun in the port nacelle. Contrary to most published reports, two prototypes of this Rolls-Royce-engined biplane were built. The first, illustrated here, made a sucessful first flight at Bracebridge Heath, near Lincoln, in September 1916 but crashed on its second flight. The second prototype differed in having equal span wings and a fixed fin in addition to the rudder.

ROBEY-PETERS. This photograph shows to advantage the gunners' nacelles on the Robey-Peters Davis-gun three-seater. It also shows how difficult the aircraft must have been to land - note the position of the pilot's cockpit