Editing Synchronization gear (section)

=== Unsynchronized guns and the "deflector wedge" concept ===
When the pilots of the British [[Royal Flying Corps]] and [[Royal Naval Air Service]] arrived in France in 1914, they were equipped with [[pusher aircraft]] too underpowered to carry machine guns and still have a chance of overtaking the enemy, and tractor aircraft which were difficult to arm effectively because the propeller was in the way. Among other attempts to get around this{{snd}}such as firing obliquely past the arc of the propeller, and even efforts, doomed to failure, to synchronize the Lewis Gun which was at the time the "standard" British aircraft weapon<ref name=Woodman4>Woodman 1989, pp. 173–180.</ref>{{snd}} was the expedient of firing straight through the propeller arc and "hoping for the best".<ref name=Woodman3>Woodman 1989, p. 173.</ref> A high proportion of bullets would in the normal course pass the propeller without striking the blades,<ref group="Note">Woodman in several places estimates the ratio of bullets striking the propeller as 25% (1:4). This seems incredibly high: A simple calculation, based on the percentage of the disc of the propeller taken up by the blades, would indicate that 12.5% (1:8) is still fairly pessimistic.</ref> and each blade might typically take several hits before there was much danger of its failing, especially if it were bound with tape to prevent splintering (see diagram below, and illustration to the left).<ref name=Mixter1/>
[[File:Unsynchronised gun.svg|thumb|180px|Unsynchronised gun – fire more or less randomly spread around propeller disc – most rounds pass but a few strike the propeller]]
After his early synchronization experiments failed, Saulnier pursued a method trusting rather less to statistics and luck by developing [[armour]]ed propeller blades that would resist damage.
[[File:Morane-Saulnier-L-airscrew-with-deflector.jpg|thumb|left|95px|Salvaged propeller with deflectors captured by the Germans.]]
By March 1915, when French pilot [[Roland Garros (aviator)|Roland Garros]] approached Saulnier to arrange for this device to be installed on his [[Morane-Saulnier Type L]], these had taken the form of steel wedges which ''deflected'' the bullets which might otherwise have damaged the propeller, or ricocheted dangerously.<ref name=Williams1.32>Williams 2003, pp. 33–34.</ref> Garros himself and his personal mechanic Jules Hue are sometimes credited with testing and perfecting the "deflectors".<ref name=Volker1p49-50>Volker 1992, pt. 1, pp. 49–50.</ref> This crude system worked after a fashion, although the wedges diminished the propeller's efficiency, and the not inconsiderable force of the impact of bullets on the deflector blades must have put undesirable stress on the engine's crankshaft.<ref name=Woodman2/>

On 1 April 1915 Garros shot down his first German aircraft, killing both the crew. On 18 April 1915, after two more victories, Garros was forced down (by ground fire) behind German lines.  Although he was able to burn his aircraft, Garros was captured and his special propeller was sufficiently intact to be sent for evaluation by the ''[[Inspektion der Fliegertruppen]]'' (''Idflieg'') at [[Dallgow-Döberitz|Döberitz]] near [[Berlin]].<ref name=VanWyngarden7/>