Dunne-Huntington triplane

{{Use dmy dates|date=January 2018}} {{Use British English|date=January 2018}} {{Infobox aircraft | name = Dunne-Huntington triplane | logo = | logo_size = | image = File:Dunne-huntington-janes-sm.jpg | alt = | caption = With original Wolseley engine and twin propellers. | long_caption = | other_names = | aircraft_type = Experimental prototype | aim = | outcome = | related = | national_origin = | manufacturer = A. K. Huntington | design_group = | designer = J. W. Dunne | builder = | issuer = | status = | owners = | primary_user = A. K. Huntington | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = 1 | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = 1914 | first_flight = 1910 | initiated = | in_service = | last_flight = | expected = | developed_from = | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}

The '''Dunne-Huntington triplane''', sometimes referred to as a biplane, was a pioneer aircraft designed by J. W. Dunne and built by A. K. Huntington. It was of unusual staggered triple-tandem configuration and an early example of an inherently stable aeroplane, flying regularly between 1910 and 1914.

==History== While working for the Army at Farnborough in 1907, J. W. Dunne agreed to design a stable aeroplane for the civilian enthusiast and metallurgy professor A. K. Huntington. Forbidden to use his secret Army design, he based it on a previous idea for a heavily staggered tandem triplane that had been trialled by Hiram Maxim for a fairground attraction. In the winter of 1907–08 he drew up two designs. One was for a small-scale glider to test the idea, which he called the D.2. The other was for the full-sized powered aeroplane. In the event the glider was never built and Huntington began directly on the full-sized craft. He finished building it in 1910.<ref name="lewis">Peter Lewis; ''British Aircraft 1909–1914'', Putnam, 1962, pages 231–232.</ref>

Huntington flew it at the Royal Aero Club grounds at Eastchurch, progressively modifying it to improve its flight characteristics between 1910 and 1914. By 1913 it had effectively become a joint design by Dunne and Huntington and was flying well.<ref name="flight1913">"The Dunne-Huntington Machine". ''Flight'', 1 March 1913. p.254.</ref>

==Description== The main feature of the design was a set of three wings, each of {{convert|10|ft|abbr=on}} chord, placed immediately fore and aft of each other. The fore-wing was of reduced span and the middle wing raised to give the appearance of a heavily staggered canard biplane. The angle of incidence of each plane was adjusted to provide longitudinal stability.

The outer sections of the rear wing were given a sharp downward angle or anhedral. Triangular outboard control surfaces were hinged on the diagonal to these sections and provided all the functions normally produced by separate elevator, aileron and rudder controls. When operated together they acted as elevators, while when operating differentially they acted as combined ailerons and rudders to bank the aircraft into a controlled turn.

The front and rear wings were fixed to a long, uncovered fuselage frame, with the front wing gently tapered. The top wing was strut-braced to the structure below. Side curtains between the two full-span wings were initially fitted.<ref name="flight1">''Flight'' 30 April 1910, [https://www.flightglobal.com/pdfarchive/view/1910/1910%20-%200333.html page 331]: ''early photograph shows side curtains in position''.</ref>

The pilot was seated above the front wing, with the engine immediately behind. Power was initially provided by a single Wolseley water-cooled inline engine chain-driving twin propellers. These were mounted in the space beneath the upper wing and their axles doubled as twin cylindrical booms connecting the fore and aft structures.

When first flown at Eastchurch in early 1910, the fuselage was originally mounted on an undercarriage comprising two main wheels, a large tail wheel and twin auxiliary skids under the nose.<ref name="flight1"/>

Later modifications included removal of the side screens, structural lightening including a revised undercarriage and, in 1913, fitting of a more powerful {{convert|70|hp|abbr=on}} Gnome air-cooled rotary engine with single engine-mounted propeller.<ref name="jane1913">Jane's All the World's Aircraft (1913), Page 5b: ''shows side curtains removed''.</ref> These enabled the craft to reach {{convert|43|mph|km/h+kn|abbr=on}}.<ref name="lewis"/><ref name="flight1913"/>

==Specifications (Re-engined)==

{{Aircraft specs |ref=Jane's (1909) ''except where specified. ''Note: Dimensions given are estimated. |prime units?=imp  |crew=1 |capacity= |length m= |length ft=50 |length in= |length note= |span m= |span ft=59 |span in= |span note= |height m= |height ft= |height in= |height note= |wing area sqm= |wing area sqft= |wing area note= |aspect ratio= |airfoil= |empty weight kg= |empty weight lb= |empty weight note= |gross weight kg= |gross weight lb= |gross weight note= |fuel capacity= |more general=  |eng1 number=1 |eng1 name=Gnome |eng1 type=Rotary |eng1 kw= |eng1 hp=70 |eng1 note=<ref name="lewis"/>

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|max speed kmh= |max speed mph=43 |max speed kts= |max speed note=<ref name="lewis"/> |cruise speed kmh= |cruise speed mph= |cruise speed kts= |cruise speed note= |stall speed kmh= |stall speed mph= |stall speed kts= |stall speed note= |never exceed speed kmh= |never exceed speed mph= |never exceed speed kts= |never exceed speed note= |range km= |range miles= |range nmi= |range note= |endurance= |ceiling m= |ceiling ft= |ceiling note= |g limits= |roll rate= |glide ratio= |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude= |lift to drag= |wing loading kg/m2= |wing loading lb/sqft= |wing loading note= |fuel consumption kg/km= |fuel consumption lb/mi= |power/mass= |thrust/weight= |more performance= |avionics= }}

==Notes== {{reflist}}

Category:Triplanes Category:1910s British experimental aircraft Category:Dunne aircraft Category:Rotary-engined aircraft Category:Aircraft first flown in 1910

Dunne-Huntington triplane

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