 Specification F.18/40, for a specialist night fighter, with nose- and turret-mounted guns, led to Gloster submitting a design based on the F.9/37, fitted with Rolls-Royce Merlin engines, a dorsal four-gun turret and Airborne Interception (AI) radar.This received support from the Air Staff who saw it as superior to the Bristol Beaufighter and the Air Ministry ordered one of the F.9/37 prototypes to be converted to the new specification as F.29/40.Unofficially known as the Gloster Reaper, it inherited the admirable handling characteristics of the F.9/37 and despite being judged superior to other designs, including turreted variants of the Beaufighter and de Havilland Mosquito, the Reaper was terminated in May 1941, for Gloster to concentrate on other work, especially the Gloster E.28/39 jet aircraft.