Editing Tractor configuration (section)

==Firing guns through the propeller==
A disadvantage of a single-engine tractor military aircraft was that it was initially impossible to fire a gun through the propeller arc without striking the blades. Early solutions included mounting guns ([[rifle]]s or [[machine gun]]s) to fire around the propeller arc, either at an angle to the side&nbsp;– which made aiming difficult&nbsp;– or on the top wing of a [[biplane]] so that the bullets passed over the propeller arc.{{citation needed|date = March 2014}}

The first system to fire through the propeller was developed by French engineer [[Eugene Gilbert]] for [[Morane-Saulnier]], and involved fitting strong metal "deflector wedges" to the propeller blades of a [[Morane-Saulnier L]] [[monoplane]], so that bullets fired when a propeller blade obstructed the line of fire were deflected rather than damaging the propeller. It was employed with immediate success by French [[aviator]] [[Roland Garros (aviator)|Roland Garros]] and was also used on at least one [[Sopwith Tabloid]] of the [[Royal Naval Air Service]].{{citation needed|date = March 2014}}

A better solution was a ''gun synchronizer'', which utilized a [[synchronization gear]] to shoot only at instants when the line of fire was unobstructed, developed by aircraft pioneer [[Anthony Fokker]] and fitted to the [[Fokker E.I]] monoplane [[1915 in aviation|in 1915]]. The first British "tractor"  designed to be fitted with synchronization gear was the [[Sopwith 1½ Strutter]]. which entered service in early 1916.{{citation needed|date = March 2014}}

The problem of firing through the propeller's arc was avoided by passing the gun barrel through the propeller's hub or spinner &nbsp;– first used in production military aircraft with the 1917 French [[SPAD S.XII]]&nbsp;{{citation needed|date = March 2014}}– or mounting guns in the wings, as was used from the early 1930s until propeller engines were superseded in the [[jet age]].