monoplane. Initially fitted with a Bristol Cherub engine as the Mk. IA, later fitted with an Armstrong Siddeley Genet engine and smaller rudders as the Mk.IB. Air Ministry Specification 23/26 was issued to Westland for a "Tailless Aeroplane for Research Purposes" which allowed the ministry to subsidise the design and manufacture of the Pterodactyl IA. The aircraft was given serial J9251 and first flew in June 1928 from Andover. Pterodactyl II and III Design projects for variants with gull wings. Pterodactyl IV Three-seat cabin monoplane of span and length, produced in 1931. Pitch and roll control by elevons. Also a braced monoplane, the wings had variable sweep through a small range of angles, to allow longitudinal trim in flight in the absence of any horizontal stabiliser. Air Ministry Specification 16/29 was issued to Westlands for an "Experimental Tailless Aircraft" with a contract to design and build one aircraft. The aircraft was given serial K1947 and first flew in March 1931 with a 120hp de Havilland Gipsy III engine in a pusher configuration. Pterodactyl V Fighter design in the form of a sesquiplane with straight lower wing. Fitted with a 600 hp Rolls-Royce Goshawk engine and two Vickers machine guns, it demonstrated equal capability to conventional fighters of the day, but other issues prevented it from going into production. Air Ministry Specification F.3/32 for a "Two-Seater Fighter Aircraft" was issued to Westlands and serial K2770 was issued, although it was first flown from Andover in May 1934 by Harold Penrose with the test serial P-8. Pterodactyl VI Proposal contemporary with the Mk V, having a reversed layout with a pusher engine and front-mounted gun turret. The variant of the Mark V was submitted for Specification F.5/33 for a two-seater fighter aircraft with front-mounted turret. The specification was withdrawn as the designs submitted did not give any advance of current fighters. Pterodactyl VII Proposal to meet Specification 1/33 for a "Tailless Boat Seaplane". It was a flying boat with two tractor and two pusher engines. The Pterodactyl was to be produced in cooperation with Saunders-Roe and models were successfully tested in a water tank by the NPL. A novel design feature was the use of a retractable outboard engine at the stern to act as a water rudder. Pterodactyl VIII Proposed Flying wing transatlantic passenger aircraft with five pusher Rolls-Royce Griffon engines, this design may have had a delta wing. Pterodactyl fighter