page_title: Nieuport 17
section_title: Design
hierarchical_section_title: Nieuport 17 / Development / Design
caption_attribution_description: English: Early Nieuport 17 at Le Bourget on 18 July 1916 making demonstration flight for British delegation
context_page_description: The Nieuport 17 C.1 was a French sesquiplane fighter designed and manufactured by the Nieuport company during World War I. An improvement over the Nieuport 11, it was a little larger than earlier Nieuports and better adapted to the more powerful engine than the interim Nieuport 16. Aside from early examples, it had the new Alkan-Hamy synchronization gear, permitting the use of a fuselage-mounted synchronised Vickers gun firing through the propeller disc.
  At the time of its introduction in March 1916, the type's outstanding manoeuvrability and excellent rate of climb gave it a significant advantage over fighters on both sides and was described as "the best pursuit plane of the day". It was used by many operators and entered service with every Allied power and copies were also operated by the Deutsche Luftstreitkräfte. Mass-produced by several French firms, the Nieuport 17 and its derivatives were built under licence in Italy by Nieuport-Macchi and in Russia by Dux. Unlicenced copies, notably the Siemens-Schuckert D.I and the Euler D.I, were produced in Germany.
  The Nieuport 21 and 23 represented relatively minor alterations. Aerodynamic refinement led to the Clerget-powered 17bis.
context_section_description: The upper wings of the Nieuport sesquiplanes used a typical structure for the period, with widely spaced spars connected with full chord ribs and compression ribs, cross-braced internally with wire and by riblets on the leading edge. The lower wing's single spar was directly below the rear spar of the upper wing and was braced with a characteristic Vee strut. The ribs, composed of ash flanges and limewood webs, featured cut-outs to lighten them. Ailerons were fitted on the top wing only and had increased chord towards the wingtips for improved stall response. They were actuated by a pair of push-pull rods that connected torque tubes running to the ailerons to the control column in the cockpit. The elevator and rudder were built up from welded steel tube and controls for these were provided via conventional cables and pulleys. The angle of incidence on the wings could be adjusted by ground crew via a single pivot joint arrangement, which was originally intended to allow the lower wing to be rotated for low speed flight but was never used. No adjustment was provided for the tailplane.
  Quite apart from the improvement in the pilot's downward view, there were aerodynamic gains from the reduction in area of the lower wing, which on a biplane produces far less lift than the upper wing, yet causes considerable drag. This helped give sesquiplanes a superior climb rate. Unfortnately at very high speeds (at what would now be termed its VNE, or "velocity, never exceed") the lower wing was prone to flutter, an aerodynamic phenomenon not fully understood at the time . The single spar was behind the centre of lift, which at high speeds could cause the lower wing to twist, increasing the angle of attack until the wing stalled, at which point it would return to its normal position, repeating until the wing snapped or the pilot slowed the aircraft. 
  British Nieuports were modified at No 2 Aeroplane Supply Depot to alleviate this problem. Late in French service, some N.17s had their lower wings replaced with spares intended for the newer Nieuport 24.
  The fuselage of the 17 was built around four ash longerons which tapered from the rectangular sheet steel engine mounting to the rudder post, with the upper longerons bowed around the cockpit, giving most of the fuselage a trapezoid cross section. This was braced with spruce struts held with diagonal bracing wires and steel plate joints. The sides and top of the forward fuselage were covered in light molded plywood panels while the rear fuselage sides were covered in fabric. Behind the pilot was a headrest, molded into the plywood top decking, which was supported by longitudinal stringers. The cowling was made of aluminium, had strengthening ribs and a pair of inset holes to provide ventilation and egress of the engine exhaust underneath. It was faired with the forward fuselage via molded side pieces. A cône de penetration (casserole de helice), resembling a spinner that didn't spin, was bolted to the front of the stationary engine crankshaft on some early examples but was generally dispensed with on later machines
  Production of the new Alkan-Hamy synchronization gear permitted the wing-mounted Lewis gun on the earliest examples to be replaced with a synchronised Vickers gun mounted on the fuselage to fire through the propeller arc. The standard Royal Flying Corps synchroniser, the Vickers-Challenger gear, was unreliable and unpopular with pilots, so that in British service the over-wing Lewis gun was retained. The Lewis gun was fitted to the new Foster mounting, a curved metal rail which allowed the pilot to slide the gun back to change ammunition drums and to clear jams. Pilots could also aim the gun upwards to shoot into the underside of aircraft above which was used to good effect by several ace pilots.
caption: Nieuport 17 in July 1916 with Lewis gun and a cône de penetration
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