Dunne D . 8 The Dunne D . 8 of 1912 was one of a series of tailless swept wing biplanes , designed by J . W . Dunne to have inherent stability . One of the few built was the only Dunne aircraft to fly , albeit very briefly , with the Royal Flying Corps ( RFC ) . Others were used by the US Signal Corps and United States Navy and the short - lived Canadian Aviation Corps . It was the latter ' s first and only warplane . Design and development . J . W . Dunne ' s first swept biplane wing aircraft , designed to have automatic stability , dated from his employment at the Balloon ( later ) Aircraft Factory at Farnborough during 1906 – 09 . To preserve military secrecy testing was done at Blair Atholl in Scotland . After leaving Farnborough , Dunne set up a private company , the Blair - Atholl Syndicate Ltd . Its first aircraft was the Dunne D . 5 . When this crashed in 1911 it was rebuilt as the D . 8 . The two models shared very similar wings and the same engine , but the D . 8 had a single pusher propeller instead of the chain - driven pair of the D . 5 . Their fuselages and undercarriages were also different . The D . 8 was a tailless four bay unstaggered biplane with its wings swept at 32° . Its constant chord wings were built up around two spruce spars , the forward one forming the leading edge . To help achieve stability the incidence and interplane gap decreased outboard , the former becoming negative . This washout on tips well behind the centre of gravity provided longitudinal stability in the same way as a conventional tailplane , set at lower incidence than the wings . Camber increased outwards . Simple , near parallel , pairs of interplane struts joined the spars . The outer interplane struts were enclosed with fabric , forming fixed side curtains that provided directional ( yaw ) stability . Wing tip elevons were used for control , operated by a pair of levers , one either side of the pilot . The D . 8 initially used just a pair of these , mounted on the upper wing , a rectangular cutout in the side curtains allowing for their movement as on the D . 5 . Large parts of the aircraft were built by Short Brothers . The D . 8 ' s water - cooled 4 - cylinder , 60 hp ( 45 kW ) Green engine directly drove a four - bladed pusher propeller , saving weight compared with the D . 5 ' s chain drive . Though it is not certain when the propeller was changed , most photographs show the Green engine driving a two - bladed airscrew . As a consequence of the propeller position the fuselage was shortened at the rear ; it was also extended in the nose . This first D . 8 seems to have been a single - seater like its D . 5 predecessor , the pilot sitting at mid chord . Contemporary sources remarked on the complexity of the D . 8 ' s undercarriage , which combined a narrow track pair of sprung wheels pair with wingtip skids . Part of its complication came from opposing springing in the absence of dampers , and part from an elaborate anti - noseover skid . In this form the D . 8 first flew in June 1912 at Eastchurch . It attended the Larkhill Military trial in August 1912 , though it did not take part in the competition . It flew regularly at Eastchurch through 1911 and 1912 and was still active there in November 1912 . Despite the two handed arrangement of the D . 8 ' s controls , the one - handed Capt . A . D . Carden gained his Royal Aero Club Aviator ' s Certificate on it in June 1912 . It is not known if this machine was later modified aerodynamically , but by August 1913 the Green engine had been replaced by an 80 hp ( 60 kW ) 7 - cylinder Gnome rotary engine . This much shorter engine also powered the second aircraft , which was a two - seater with the pilot placed just ahead of the wing leading edge and the passenger ( who had dual control ) at the trailing edge . There were now control surfaces on both upper and lower wings , the side curtains having a pair of tapered notches to allow them to move . Each of the upper wings carried a pair of elevons , nearly doubling the control surface area , though it is not certain if these moved as one or differentially . It first flew , with Felix at the controls , on 18 October 1913 . In August 1913 Commandant Felix piloted a D . 8 across the English Channel from Eastchurch to Villacoublay . Nieuport had obtained a licence to build the D . 8 and Felix gave demonstration flights in France on their behalf . A Nieuport - built Dunne appeared at the Paris Aero Salon in December 1913 . Like the second D . 8 it was a Gnome powered two - seater , but with significant differences both aerodynamically and structurally . It combined the double upper wing elevons into a single surface and had very rounded rear wingtips . The fuselage was slightly modified and built around steel tubes rather than wood . The interplane struts were streamlined steel tubes . It also had a strikingly simplified undercarriage . Dunne had obtained a War Office order for two D . 8s , though one was cancelled because of late delivery . One , possibly the machine flown in October 1913 and certainly similar to it , was delivered to Farnborough on 3 March 1914 . It made several flights on 11 March piloted by N . S . Percival , who had flown the first D . 8 many times at Eastchurch and was now a RFC officer . Though it carried the RFC number 366 , there is no record of it flying again though it may have survived until at least the summer of 1914 . The general judgement was that in the search for balance between stability and controllability , the Dunne design overemphasised the former . Variants . There is a full scale , non - flying replica of a Burgess - Dunne in the RCAF Memorial Museum , CFB Trenton , Ontario , largely built by Barry D . MacKeracher .