Editing Synchronization gear (section)

=== Decline and end of synchronization ===
[[File:Bf 109E-3 in flight (1940).jpg|thumb|A [[Messerschmitt Bf 109E]] showing a traditional pair of synchronized machine guns, a ''motorkanone'' firing through the propeller hub and wing guns]]
The usefulness of synchronization gears naturally disappeared altogether when [[jet engine]]s eliminated the propeller, at least in fighter aircraft, but gun synchronization, even in single reciprocating engine aircraft, had already been in decline for twenty years prior to this.

The increased speeds of the new monoplanes of the mid to late 1930s meant that the time available to deliver a sufficient weight of fire to bring down an enemy aircraft was greatly reduced. At the same time, the primary vehicle of air power was increasingly seen as the large all-metal bomber: powerful enough to carry armour protection for its vulnerable areas. Two rifle-calibre machine guns were no longer enough, especially for defence planners who anticipated a primarily strategic role for airpower. An effective "anti-bomber" fighter needed something more.

Cantilever monoplane wings provided ample space to mount armaments and, being much more rigid than the old cable-braced wings, they afforded almost as steady a mounting as the fuselage. This new context also made the [[Gun harmonisation|harmonisation]] of wing guns more satisfactory, producing a fairly narrow cone of fire in the close to medium ranges at which a fighter's gun armament was most effective.

[[File:Hurricane mockup.jpg|thumb|Mockup of the fuselage of Hawker Hurricane prototype – showing the installation of Merlin Engine and originally projected synchronized Vickers machinegun (later deleted)]]The retention of fuselage-mounted guns, with the additional weight of their synchronization gear (which slowed their rate of fire, albeit only slightly, and still occasionally failed, resulting in damage to propellers) became increasingly unattractive. This design philosophy, common in Britain and France (and, after 1941, the United States) tended towards eliminating fuselage mounted guns altogether. For example, the original 1934 specifications for the [[Hawker Hurricane]] were for a similar armament to the Gloster Gladiator: four machine-guns, two in the wings and two in the fuselage, synchronized to fire through the propeller arc. The illustration opposite is of an early mock-up of the prototype, showing the starboard fuselage gun. The prototype (''K5083'') as completed had ballast representing this armament; production Hurricane Is, however, were armed with eight guns, all in the wings.<ref name=Masonp21>Mason 1962, p. 21</ref>

Another approach, common to [[Luftwaffe|Germany]], the [[Soviet Air Forces|Soviet Union]], and [[Imperial Japanese Army Air Service|Japan]], while recognising the necessity to increase armament, preferred a system that included synchronized weapons. Centralised guns had the real advantage that their range was limited only by ballistics, as they did not need the [[gun harmonisation]] necessary to concentrate the fire of wing-mounted guns. They were seen as rewarding the true marksman, as they involved less dependence on gun sight technology. Mounting guns in the fuselage also concentrated mass at the centre of gravity, thus improving the fighter's roll ability.<ref>{{Cite web|url=http://www.quarryhs.co.uk/ideal.htm|title = Ideal Ww2 Fighter Armament}}</ref> More consistent ammunition manufacture, and improved synchronization gear systems made the whole concept more efficient and effective, whilst facilitating its application to weapons of increased calibre such as [[autocannon]]; moreover the [[constant-speed propeller]]s that quickly became standard equipment on WW II fighters meant that the ratio between the propeller speed and the rate of fire of the guns varied less erratically.

The swan-song of synchronization belongs to the last reciprocating engine Soviet fighters, which largely made do with slow firing synchronized cannon throughout the [[World War II]] period and after. The very last synchronizer-equipped aircraft to see combat action were the [[Lavochkin La-11]] and the [[Yakovlev Yak-9]] during the [[Korean War]].<ref name=Volker2p75>Volker 1992, pt. 2, p. 76</ref>