In 1923, Gloster modified a Gloster Sparrowhawk fighter trainer with new wings to test a layout proposed by chief designer Henry Folland, combining a thick, high-lift section upper wing and a thinner, medium-lift lower wing, with the intention of combining high lift for takeoff with low drag. After the Grouse demonstrated that the new layout was a success, the British Air Ministry placed an order for three prototype fighters based on the Grouse, but powered by a Armstrong Siddeley Jaguar IIIradial engine, as the "Nighthawk ". The first of the prototypes, by now known as the Grebe I, flew during May 1923. The performance of these prototypes during testing at RAF Martlesham Heath was good, and the Air Ministry decided to order the type into production as the Grebe II, this having a Jaguar IV engine. Like the Sopwith Snipe it replaced, the Grebe was a single-seat, single-engined biplane of fabric-covered wood construction. The fuselage had ash longerons and spruce stringers joined to plywood formers, while the single-bay wings, had fabric-covered spruce spars and ribs. Two synchronised.303 in Vickers machine guns were mounted on the fuselage top decking.
Service history
Grebes entered service with the RAF during October 1923 when a flight of 111 Squadron re-equipped with the new fighter. The Grebe was popular in RAF service, being much faster than the Snipe that it replaced and was also very agile. One problem with the Grebe was that it suffered from wing flutter, owing to the large overhang outside the interplane struts, which led to all RAF aircraft being modified with additional Vee-struts supporting the outer upper wing. Another problem was the Jaguar engine, which was heavy and unreliable, being prone to catching fire. A total of 133 Grebes were produced, including the four prototypes, 108 Grebe II single-seat fighters and 21 two-seat dual-control trainers. Grebes were retired from the RAF in 1929, replaced in part by the Gloster Gamecock, which was a developed Grebe,. Two Grebes were modified for suspension beneath the R33 airship on a 'trapeze' for "parasite" trials. The Grebe was developed into the Gloster Gamecock fighter, which also entered production for the RAF. A Grebe was given to New Zealand by Sir Henry Wigram and another two Grebes were acquired by the New Zealand Permanent Air Force, fore-runner of the Royal New Zealand Air Force, entering service in March 1928 and serving for more than ten years until the mid-1938. The two survivors were used as instructional airframes until destroyed in 1943–44.
Variants
;Gloster Grouse: Experimental aircraft. ;Grebe Mk I: Single-seat fighter prototype, 4 built. ;Grebe Mk II: Production single-seat fighter variant with a 400 hp Armstrong Siddeley Jaguar IV engine, oleo-type landing gear and other modifications, 129 built. ;Grebe : Following a trial modification to Grebe II J7519 a small number of the Grebe II production aircraft were completed as two-seat training aircraft in 1925.
