Editing Pusher configuration (section)

==History==
[[File:Pénaud's flying models (cropped).jpg|thumb|1871 ''Planophore'']]
[[File:Farman MF.11 (SDASM Archives 00079053).jpg|thumb|A [[Farman MF.11]], showing the classic Farman configuration with engine between tail booms]]
[[Image:Buhl A-1 Autogiro - autogyro with rear push propeller engine - designer Etienne Dormoy and pilot James Johnson - 1931.jpg|thumb|[[Buhl A-1 Autogyro]], the first pusher autogyro]] 

[[File:Convair B-36 Peacemaker.jpg|thumb|The post-WWII [[Convair B-36]] was unusual in its size, era, number of engines, and combining both propeller and jet propulsion, with six [[radial engine|radial]] piston and four jet engines]]

[[Image:MQ-9 Reaper in flight 2.jpg|thumb|Typical of many [[UAV]]s, the [[General Atomics MQ-9 Reaper]] has a propeller at the extreme tail]]
[[Image:HAL Saras.jpg|thumb|[[NAL Saras]], with pushers mounted on pods on either side of the rear fuselage]]

The rubber-powered "Planophore", designed by [[Alphonse Pénaud]] in 1871, was an early successful model aircraft with a pusher propeller.

Many early aircraft (especially biplanes) were "pushers", including the [[Wright Flyer]] (1903), the [[Santos-Dumont 14-bis]] (1906), the [[Voisin 1907 biplane|Voisin-Farman I]] (1907), and the [[Curtiss Model D]] used by [[Eugene Burton Ely|Eugene Ely]] for the first ship landing on January 18, 1911. [[Henri Farman]]'s pusher [[Farman III]] and its successors were so influential in Britain that pushers in general became known as the "Farman type".<ref group="note">The [[Royal Aircraft Factory]] referred to all the early pushers they built as Farman Experimentals - or F.E.s.</ref> Other early pusher configurations were variations on this theme.

The classic "Farman" pusher had the propeller "mounted (just) behind the main lifting surface" with the engine fixed to the lower wing or between the wings, immediately forward of the propeller in a stub fuselage (that also contained the pilot) called a [[nacelle]]. The main difficulty with this type of pusher design was attaching the tail (empennage). This needed to be in the same general location as on a tractor aircraft, but its support structure had to avoid the propeller. 

The earliest examples of pushers relied on a canard but this has serious aerodynamic implications that the early designers were unable to resolve. Typically, mounting the tail was done with a complex wire-braced framework that created a lot of drag. Well before the beginning of the [[World War I|First World War]], this drag was recognized as just one of the factors that would ensure that a Farman-style pusher would have an inferior performance to an otherwise similar [[Tractor configuration|tractor type]].

The U.S. Army banned pusher aircraft in late 1914 after several pilots died in crashes of aircraft of this type,<ref>{{cite web|publisher= US Centennial of Flight Commission|url=http://www.centennialofflight.net/essay/Dictionary/Propeller_Design/DI62.htm|title= Propeller Configurations|website=www.centennialofflight.net|url-status=live|archive-url=https://web.archive.org/web/20140121003417/http://www.centennialofflight.net/essay/Dictionary/Propeller_Design/DI62.htm|archive-date=2014-01-21}}</ref> so from about 1912 onwards, the great majority of new U.S. landplane designs were tractor biplanes, with pushers of all types becoming regarded as old-fashioned on both sides of the Atlantic. However, new pusher designs continued to be designed right up to the armistice, such as the [[Vickers Vampire]], although few entered service after 1916.{{Citation needed|date=October 2011}}

At least up to the end of 1916, however, pushers (such as the [[Airco DH.2]] fighter) were still favored as gun-carrying aircraft by the [[Royal Flying Corps|British Royal Flying Corps]], because a forward-firing gun could be used without being obstructed by the arc of the propeller. With the successful introduction of [[Fokker]]'s [[synchronization gear|mechanism for synchronizing the firing of a machine gun with the blades of a moving propeller]],<ref>{{cite book |last= Guttman|first= Jon|others= Illustrated by Harry Dempsey|date= 10 September 2009|title= Pusher Aces of World War 1|location= Oxford, England|publisher= Osprey Publishing|pages= 6–7|isbn= 9781846034176}}</ref> followed quickly by the widespread adoption of synchronization gears by all the combatants in 1916 and 1917, the tractor configuration became almost universally favored, and pushers were reduced to the tiny minority of new aircraft designs that had a specific reason for using the arrangement. 

Both the British and French continued to use pusher-configured bombers, though there was no clear preference either way until 1917. Such aircraft included (apart from the products of the Farman company) the [[Voisin (aircraft)|Voisin]] bombers (3,200 built), the [[Vickers F.B.5]] "Gunbus", and the [[Royal Aircraft Factory F.E.2]]; however, even these found themselves being shunted into training roles before disappearing entirely. Possibly the last fighter to use the Farman pusher configuration was the 1931 [[Vickers Type 161]] COW gun fighter.

During the long eclipse of the configuration the use of pusher propellers continued in aircraft which derived a small benefit from the installation and could have been built as tractors. Biplane [[flying boat]]s had for some time often been fitted with engines located above the fuselage to offer maximum clearance from the water, often driving pusher propellers to avoid spray and the hazards involved by keeping them well clear of the cockpit. The [[Supermarine Walrus]] was a late example of this layout.

The so-called [[push-pull configuration|push/pull layout]], combining the tractor and pusher configurations—that is, with one or more propellers facing forward and one or more others facing back—was another idea that continues to be used from time to time as a means of reducing the asymmetric effects of an outboard engine failure, such as on the [[Farman F.220|Farman F.222]], but at the cost of a severely reduced efficiency on the rear propellers, which were often smaller and attached to lower-powered engines as a result.

By the late 1930s, the widespread adoption of all-metal stressed skin construction of aircraft meant, at least in theory, that the aerodynamic penalties that had limited the performance of pushers (and indeed any unconventional layout) were reduced; however, any improvement that boosts pusher performance also boosts the performance of conventional aircraft, and they remained a rarity in operational service—so the gap was narrowed but was closed entirely.

During [[World War II]], experiments were conducted with pusher fighters by most of the major powers. Difficulties remained, particularly that a pilot having to bail out of a pusher was liable to pass through the propeller arc. This meant that of all the types concerned, only the relatively conventional Swedish [[SAAB 21]] of 1943 went into series production. Other problems related to the aerodynamics of canard layouts, which had been used on most of the pushers, proved more difficult to resolve.<ref group="note">See stability issues of the [[Curtiss-Wright XP-55 Ascender]]</ref> One of the world's first [[ejection seat]]s was (per force) designed for this aircraft, which later re-emerged [[Saab 21R|with a jet engine]].

The largest pusher [[fixed-wing aircraft|aircraft]] to fly was the [[Convair B-36 Peacemaker|Convair B-36 "Peacemaker"]] of 1946, which was also the largest bomber ever operated by the [[United States]]. It had six {{cvt|3,800|hp|kW}} 28-cylinder [[Pratt & Whitney R-4360 Wasp Major|Pratt & Whitney Wasp Major]] [[radial engine]]s mounted in the wing, each driving a pusher propeller located behind the trailing edge of the wing, plus four jet engines.
[[File:Sparrow Hawk II.jpg|thumb|Aero Dynamics Sparrow Hawk II]]
Although the vast majority of propeller-driven aircraft continue to use a tractor configuration, there has been in recent years something of a revival of interest in pusher designs: in light [[homebuilt aircraft]] such as [[Burt Rutan]]'s [[Canard (aeronautics)|canard]] designs since 1975, ultralights such as the [[Quad City Challenger]] (1983), flexwings, [[paramotors]], [[powered parachute]]s, and [[autogyro]]s. The configuration is also often used for [[unmanned aerial vehicle]]s, due to requirements for a forward fuselage free of any engine interference.

The [[Aero Dynamics Sparrow Hawk]] was another homebuilt aircraft constructed chiefly in the 1990s.