Sopwith L.R.T.Tr.

{{short description|British WW1 triplane escort fighter aircraft}} {{Use dmy dates|date=December 2016}} {{Use British English|date=December 2016}}  {{Infobox aircraft | name = L.R.T.Tr. | logo = | logo_size = | image = | alt = | caption = | long_caption = | other_names = | aircraft_type = Escort fighter | aim = | outcome = | related = | national_origin = [[United Kingdom]] | manufacturer = [[Sopwith Aviation Company|Sopwith]] | design_group = | designer = | builder = | issuer = | status = Prototype | owners = | primary_user = | 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 = | first_flight = 1916 | initiated = | in_service = | last_flight = | expected = | developed_from = | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }} The '''Sopwith Long Range Tractor Triplane''' (L.R.T.Tr) was a prototype [[United Kingdom|British]] long-range three-seat [[triplane]] escort fighter of the [[First World War]]. Its unusual layout had a small gunner's [[nacelle]] mounted on the upper wing for an all-round field of fire. Only a single example was built, as other, smaller fighters proved more practicable.

==Development and design== In early 1916, the British [[War Office]] drew up a specification for a multi-seat escort fighter to be powered by one of the new [[Rolls-Royce Eagle]] engines, intended to protect formations of bombers from German fighters, with an additional role of destroying enemy [[airship]]s.<ref name=bruce1957p25>Bruce 1957, p. 25.</ref> While the specification did not require high speed, a good field of fire for its guns was essential,<ref>Mason 1992, p. 67.</ref> while the secondary anti-Zeppelin role demanded an endurance of at least seven hours.<ref name=bruce1957p25/>

Orders were placed for prototypes from [[Armstrong Whitworth Aircraft|Armstrong Whitworth]] (the [[Armstrong Whitworth F.K.6|F.K.6]]), [[Sopwith Aviation Company|Sopwith]] and [[Vickers Limited|Vickers]] (the [[Vickers F.B.11|F.B.11]]). All three designs were driven by the need to provide wide fields of fire in the absence of an effective [[Synchronization gear|synchronisation gear]] that would allow safe firing of guns through the propeller disc.<ref name=bruce1957p25/>

The Sopwith proposal was modified from an existing design for a two-seat [[triplane]], with a nacelle for a gunner added to the upper wing.<ref>Bruce 1968, pp. 139–140.</ref> It had three-bay, narrow chord wings, with the streamlined nacelle housing the upper gunner who was armed with a [[Lewis gun]] built around the centre section of the upper wing.<ref>Bruce 1968, p. 140.</ref> [[Aileron]]s were fitted to all wings, with [[Air brake (aircraft)|air brakes]] fitted to the lower wing. The deep [[fuselage]] housed the pilot and a second gunner to guard the aircraft's tail.<ref name=mason78>Mason 1992, p. 78.</ref> Balancing wheels were fitted well ahead of the aircraft's mainwheels in order to prevent the aircraft overturning, as the upper gunner would be extremely vulnerable if this occurred.<ref>Bruce 1968, p. 141.</ref>

The prototype, which was nicknamed "Egg-Box",<ref>Green and Swanborough 1994, p. 535.</ref> flew late in 1916.<ref name=mason78/> It was not developed further, with smaller fighters fitted with [[synchronization gear|synchronisation gear]] such as Sopwith's own [[Sopwith 1½ Strutter|1½ Strutter]] now available, with all of the proposed three-seat escort fighters abandoned.<ref>Lewis 1979, p. 99.</ref>

==Specifications (L.R.T.Tr.)== {{Aircraft specs |ref=War Planes of the First World War:Volume Two Fighters <ref>Bruce 1968, p. 142.</ref> |prime units?=imp  |genhide=

|max speed kmh= |max speed mph=107 |max speed kts= |max speed note= (approx.)<ref>Mason 1992, p. 79.</ref> |max speed mach= |cruise speed kmh= |cruise speed mph= |cruise speed kts= |range km= |range miles= |range nmi= |endurance= |ceiling m= |ceiling ft= |climb rate ms= |climb rate ftmin= |more performance=  |guns= <br/> **1× [[.303 British|.303 in]] (7.7 mm) [[Lewis gun]] in nacelle **1× Lewis gun in rear cockpit }}

==See also== {{aircontent  |see also= |related= |similar aircraft=*[[Armstrong Whitworth F.K.6]] *[[Vickers F.B.11]] |lists= }}

==Notes== {{reflist}}

==References== {{refbegin}} *Bruce, J. M. ''British Aeroplanes 1914-18''. London: Putnam, 1957. *Bruce, J. M. ''War Planes of the First World War: Volume Two Fighters''. London: Macdonald, 1968. {{ISBN|0-356-01473-8}}. *Green, William, and Swanborough, Gordon. ''The Complete Book of Fighters''. New York: Smithmark, 1994. {{ISBN|0-8317-3939-8}}. *Lewis, Peter. ''The British Fighter since 1912''. London: Putnam, Fourth edition, 1979. {{ISBN|0-370-10049-2}}. *Mason, Francis K. ''The British Fighter since 1912''. Annapolis, Maryland, USA: Naval Institute Press, 1992. {{ISBN|1-55750-082-7}}. {{refend}}

[[Category:Triplanes]] [[Category:Sopwith aircraft|L.R.T.Tr]] [[Category:Aircraft first flown in 1916]] [[Category:1910s British fighter aircraft]]