Short Gurnard The Short Gurnard was a single - engined two - seat biplane naval fighter , built in the United Kingdom to an Air Ministry specification in 1929 . It failed to win production orders and only two flew . Design and development . The duralamin - framed Short Sturgeon had never been expected to achieve production status , but the Air Ministry were sufficiently impressed with its behaviour on water and in the air to invite Shorts to tender for Air Ministry specification O . 22 / 26 , a two - seat fleet fighter . The specification sought a Fairey Flycatcher replacement , an aircraft that would spend much time in fleet spotter and reconnaissance roles , though without the third crew member the navy usually thought necessary for the latter task ; but it also was to have the speed and rate of climb to catch bombers . It was required to be able to perform as a deck lander or a seaplane , and to be strong enough in either configuration to be launched by catapult . Shorts were advised that their duralumin monocoquue fuselage was not suitable for below deck maintenance . Their tender was rewarded with an order for two prototypes of the S . 10 Gurnard . As a result of the Air Ministry comments , the fuselage of the Gurnard was quite different from Shorts recent series of single - engined monocoques . It was a welded steel tube structure with duralumin detachable panels forward and fabric covering aft . The two separate open cockpits were very close together , the pilot sitting in front just under a visibility cut - out in the trailing edge of the upper wing , raised up for a better view over the nose . A 0 . 303 in ( 7 . 7 mm ) Vickers machine gun operated by the pilot was mounted on the decking in front of him , slightly to port . The rear cockpit was fitted with a Lewis gun on a Scarff ring . The steel fuselage stopped at the rear with an attachment for the only monocoque part of the Gurnard , the empennage - carrying tail cone . The fin and rudder leading edge was rounded , the trailing edge of the horn balanced rudder straight . The latter extended below the fuselage , with additional fixed surface in front of it . These surfaces were fabric covered . The two Gurnard prototypes had different engines . The Gurnard II , the first to be completed , had a 525 hp ( 392 kW ) Rolls - Royce Kestrel IIS supercharged water - cooled inline and the Gurnard I a 525 hp Bristol Jupiter X supercharged radial engine . Accordingly , the Gurnard II had a smooth and pointed cowling , with a drum - shaped radiator between the undercarriage legs , whilst the radial engine had a narrow chord Townend ring , with the rear part of its cylinders visible from the side . The Gurnard was a single - bay biplane . It had straight - edged , constant chord wings , the lower one being slightly shorter in span and markedly narrower in chord . Both wings carried dihedral , the upper plane the most . The wings were duralumin structures , fabric covered , with simple , near - parallel interplane struts between the spars . The centre section was supported by a pair of struts from the upper fuselage on each side . Long Frise ailerons were fitted to the upper wing only . The wheeled undercarriage was a simple single - axle arrangement , with oleo legs forward to the engine bulkhead and rearward bracing struts to the root of the rear wing spar . There was a rather long tailskid to protect the downward - extended fin . The seaplane version used a pair of floats , their low drag profile refined via Schneider Trophy experience , cross braced with a pair of horizontal transverse struts . They were mounted with N - shaped struts which sloped strongly outwards from the fuselage . The Gurnard II , fitted with floats , was the first to fly , taking off from the Medway off Shorts ' Rochester factory on 16 April 1929 . The pilot was John Lankester Parker . In May both Gurnards flew as landplanes from Lympne , where Shorts maintained a base . By early June both aircraft were at RAF Martlesham Heath for evaluation against the specification , though they both returned briefly to Shorts for some modifications . The water - based testing was done at the Marine Aircraft Experimental Establishment at Felixstowe . The Gurnards flew well and met the specifications , but were out - performed by the Hawker Osprey , a close relative of the RAF ' s established bomber the Hawker Hart , so no more Gurnards were produced . Shorts did get a useful order for large numbers of their floats for the Ospreys . The Gurnard II returned from Martlesham to Rochester in 1931 for conversion into an amphibian . This involved the fitting of a single , central float which carried a pair of wheels using an axle that passed through its top . The wheels were on stubs offset from the axle , so that in one position they were lifted above the water , but rotated through 180° from the pilot ' s cockpit they reached the ground . A similar , smaller version had been used successfully on the Short Mussel and on a converted Moth . The central float was again mounted with a pair of N - shaped struts , now vertical . There was a pair of outboard stabilising floats beyond the interplane struts , each mounted on a pair of vertical legs . The floats were each directly braced with a pair of struts to the interplane struts from below , and from above by a pair of struts from the top of the rear interplane strut to the tops of the legs . It first flew in this configuration in June 1931 and returned to Martlesham within the month , appearing in that year ' s Hendon RAF Display . After that it came back for while to Rochester , where it was used to investigate cooling of the Kestrel engine . At this time it was flying with a tall pillar radiator between fuselage and float . In October the float was modified , and later that month six flights were made between Lympne airfield ( land ) and the Medway ( water ) in a total of 90 minutes . In December it returned to Felixstowe , where it served as an engine and cooling system test - bed .