Damaged propeller from a Sopwith Baby aircraft circa 1916/17 with evidence of bulletholes from a machine gun fired behind the propeller without an interrupter. A propeller is essentially a type of fan which transmits power by converting Rotational motion into Thrust for propulsion of a vehicle such as an The Sopwith Aviation Company was a British Aircraft company that designed and manufactured aeroplanes mainly for the British Royal Flying Corps, Royal The Sopwith Baby was a British single-seat Seaplane used by the Royal Naval Air Service (RNAS from 1915 The propeller required immediate replacement after the aircraft landed.

Interrupter gear is a term that covers two related technologies.

The first is the synchronization gear, which is often incorrectly referred to as "interrupter gear"; this is a triggering device attached to the machine gun armament of a tractor-type fighter aircraft so that it would fire only at certain times. For other uses of the phrase see Machine Gun (disambiguation. An Aircraft constructed with a tractor configuration has the engine mounted with the Propeller facing forwards such that the aircraft is "pulled" A fighter aircraft is a Military aircraft designed primarily for air-to-air combat with other Aircraft, as opposed to a Bomber, which is designed This allows the gun to fire through the arc of a spinning propeller without the bullets striking the blades. A propeller is essentially a type of fan which transmits power by converting Rotational motion into Thrust for propulsion of a vehicle such as an Introduced during the First World War, the gun synchronizer was a significant development in the history of air combat and remained in operational use until the Korean War when the widespread adoption of jet aircraft rendered them obsolete. World War I (abbreviated WWI; also known as the First World War, the Great War, and the War to End All Air power redirects here for electrical and mechanical energy supplied by air movement see Wind power The Korean War refers to a period of military conflict between North Korean and South Korean regimes with major hostilities lasting from June 25 1950 until the A jet aircraft is an Aircraft propelled by Jet engines Jet aircraft fly much faster than Propeller -powered aircraft and at higher altitudes -- as high as

A true interrupter gear stopped the firing of the machine gun when some part of the aircraft was in the way. For much of the early history of the fighter aircraft this was limited to the propeller. This would change with the introduction of turret mounted armament firstly to the bomber aircraft and briefly to the fighter. A gun turret is a device that protects the crew or mechanism of a projectile firing weapon and at the same time lets the weapon be aimed and fired in many directions

Though their effects were the same, there was a subtle difference between the concept of the interrupter and the synchronizer. A machine gun fitted with interrupter gear had the trigger normally enabled and the interrupter mechanism would disable the trigger when a propeller blade was in the way. A trigger is a Mechanism that actuates the firing sequence of Firearms Triggers almost universally consist of Levers or buttons actuated by the Index A machine gun fitted with synchronization gear had the trigger normally disabled and the synchronizer mechanism would enable the trigger when the propeller was clear. In reality, the technical difficulties associated with reliably halting the firing of a Maxim-type machine gun meant that no working interrupter system was ever developed — all successful implementations used the concept of synchronization. The Maxim gun was the first self-powered Machine gun, invented by the American-born Briton Sir Hiram Maxim in 1884

Origins

Experimentation with gun synchronization had been underway in France and Germany before the First World War but the engineers involved received little support or encouragement from the military who disregarded the need for armed aircraft, believing them solely useful for reconnaissance. This article is about the country For a topic outline on this subject see List of basic France topics. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Reconnaissance (also scouting) is a military and medical term denoting exploration conducted to gain information Swiss engineer Franz Schneider, working for LVG, designed and patented a synchronizer in 1913. Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an Year 1913 ( MCMXIII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common French aircraft designer Raymond Saulnier built and patented a practical gun synchronizer in April 1914, having borrowed a machine gun from the army for testing. Year 1914 ( MCMXIV) was a Common year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Common year No design was developed to the point of being operational in the field, one significant problem being the inconsistency of ammunition propellant resulting in hang fire rounds. A propellant is a material that is used to move ("propel" an object " Hang Fire " is a song by Rock and roll band The Rolling Stones off their 1981 release Tattoo You.

Saulnier pursued a simpler method using armoured propeller blades. Armour (or armor) is protective covering most commonly manufactured from metals to prevent damage from being inflicted to an individual or a vehicle through use of direct contact In December 1914, French pilot Roland Garros approached Saulnier to arrange for this device to be installed on his aeroplane but it was not until March 1915 that he took to the air with a forward-firing Hotchkiss 8 mm (. Roland Garros ( October 6 1888 &ndash October 5 1918) was an early French Aviator and a Fighter aircraft Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year 323 in) machine gun mounted on his Morane-Saulnier Type L. In addition to the armoured blades, Garros's mechanic, Jules Hue, attached deflector wedges to the blades. While this reduced the chance of a dangerous ricochet, the wedges diminished the propeller's efficiency. A ricochet (ˈrɪkəʃeɪ RICK-uh-shay) is a rebound bounce or skip off a surface particularly in the case of a Projectile. On 18 April 1915, having shot down three German aircraft, Garros' plane was forced down in German territory. Events 1025 - Bolesław Chrobry is crowned in Gniezno, becoming the first King of Poland. Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year Before he could burn his aircraft, he was captured and the gun and propeller were sent for evaluation by the Inspektion der Fliegertruppen (Idflieg) at Döberitz near Berlin. The Idflieg ( Inspektion der Fliegertruppen - "Inspectorate of Flying Troops" was the bureau of the German War Office that oversaw German Dallgow-Döberitz is a Municipality in the Havelland district in Brandenburg, Germany. Berlin is the capital city and one of sixteen states of Germany.

Fokker's synchronizer

Popular accounts claim that Dutch aircraft designer Anthony Fokker was then asked to reproduce Saulnier's deflectors and proceeded to invent the synchronization system in a matter of days — according to some accounts, Fokker was given the problem on a Tuesday evening and presented a working system on Friday. The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout However, Fokker's team, including engineer Heinrich Lübbe, had been working on a synchronization mechanism since late 1914, probably based on Schneider's patent. Heinrich Lübbe ( 12 January, 1884 &ndash 14 March, 1940) was a German engineer working for Dutch aircraft designer Indeed in 1916 LVG and Schneider sued Fokker for patent infringement — the battle continued until 1933 and though the courts repeatedly found in Schneider's favour, Fokker refused to acknowledge the rulings. Year 1916 ( MCMXVI) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Leap year In law a lawsuit is a civil action brought before a Court in which the party commencing the action the Plaintiff, seeks a legal or equitable remedy Patent infringement is the act of utilizing a patented Invention without permission from the Patent holder Year 1933 ( MCMXXXIII) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar.

Diagram of Fokker's "Zentralsteuerung" synchronization mechanism. Pulling the green handle lowers the red cam follower onto the cam wheel attached to the propeller shaft. When the cam raises the follower, the blue rod is depressed against the spring, enabling the yellow trigger plate to be reached when the purple firing button is pressed. This image shows a side view of one of the original Spandau LMG 08 guns, somewhat different in appearance from the LMG 08/15 that later German fighters used

Fokker's team adapted their system to work with the new Parabellum lMG 14 machine gun fitted to a Fokker A.III unarmed single-seat monoplane (a military version of the Fokker M.5K) usually flown by Leutnant Otto Parschau. The Parabellum MG14 was a 792 mm caliber World War I machine gun built by Deutsche Waffen und Munitionsfabriken. The Fokker M5 was an unarmed single-seat Monoplane aircraft designed and built by Anthony Fokker in 1913. For Félix du Temple 's invention see ''Monoplane'' (1874 Types of monoplane The main distinction in types of monoplane is The Fokker M5 was an unarmed single-seat Monoplane aircraft designed and built by Anthony Fokker in 1913. This aircraft — the first example of the five M. 5K/MG production prototypes for the Fokker E.I — was demonstrated on 19–20 May 1915 and shipped to the Western Front on 30 May 1915. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout Events 1535 - French explorer Jacques Cartier sets sail on his second voyage to North America with three ships 110 men and Events 325 - The First Council of Nicaea &ndash the first Ecumenical Council of the Christian Church is held Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year Events 1416 - The Council of Constance, called by the Emperor Sigismund a supporter of Antipope John XXIII burns Jerome of Prague following Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year

The solution used a cam attached to the propeller shaft that pressed on a long rod running to the trigger of the guns. A cam is a projecting part of a rotating Wheel or shaft that strikes a Lever at one or more points on its circular path The cam was set such that the propeller was horizontal when it pushed on the rod, and the rod in turn pressed the trigger to fire a bullet. The trigger operated by the pilot pulled the rod into position over the cam.

The first victory using a synchronized gun-equipped fighter is believed to have occurred on 1 July 1915 when Lieutenant Kurt Wintgens of Feldflieger Abteilung 67, flying the Fokker M. "July 1st" redirects here For the Ayumi Hamasaki song see H (song. Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year 5K/MG serial number 'E. 5/15', forced down a French Morane-Saulnier Type L east of Lunéville. Lunéville is a commune in the French région of Lorraine. It is a Sous-préfecture of the Meurthe-et-Moselle However the plane landed in French territory and the victory could not be confirmed. The first confirmed victory went to Max Immelmann flying a Fokker E. } Max Immelmann ( September 21, 1890 – June 18, 1916) was a German World War I Flying ace. I on 1 August 1915, forcing down a Royal Flying Corps B.E.2c. Events 30 BC - Octavian (later known as Augustus enters Alexandria, Egypt, bringing it under the control of the Roman Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year The Royal Flying Corps (RFC was the over-land air arm of the British military during most of the First World War. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout

Sole possession of a working synchronizer enabled Germany to dominate the Western Front skies in a period known as the Fokker Scourge. Following the outbreak of World War I in 1914 the German army opened the Western Front by first invading Luxembourg and Belgium, then gaining The Fokker Scourge was a term coined by the British press in the summer of 1915 to describe the then-current ascendency of the Fokker Eindecker monoplane fighters Initially lacking a synchronizer, the Royal Flying Corps relied on pusher aircraft such as the Vickers F.B.5 Gunbus and the Airco D.H.2 which did not have the problem of firing forwards through the propeller. The Royal Flying Corps (RFC was the over-land air arm of the British military during most of the First World War. An Aircraft constructed with a pusher configuration has the engine mounted forward of the Propeller - which faces in a rearwards direction - giving an appearance WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout The Airco DH2 was a single-seat Biplane " pusher " aircraft which operated as a fighter Germany was protective of the synchronizer system, instructing pilots not to venture over enemy territory in case they were forced down and the secret revealed, but by 1916 the Allies had developed various synchronizer mechanisms of their own, usually based on cams and links, like the Fokker mechanism. Year 1916 ( MCMXVI) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Leap year

Further development

The first British aircraft to use a synchronizer gear was the Sopwith 1½ Strutter which arrived in April 1916 equipped with the Ross synchronizer, although some other service types were retrofitted with synchronised guns about this time, including the Nieuport 12 and the Bristol Scout. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout Year 1916 ( MCMXVI) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Leap year WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout For the later monoplane see Bristol M1 Monoplane Scout The Bristol Scout was a simple single seat rotary-engined Biplane The main problem with early mechanical synchronizers was that the rate of fire of the machine gun was dependent on the engine revolutions, and was slowed, especially when the engine was throttled back. The mechanical linkages were also very liable to failure, resulting in the unfortunate pilot shooting away his own propeller.

Eventually all British aircraft were equipped with the superior hydraulic Constantinesco synchronization gear (or "CC" gear, invented by Romanian engineer George Constantinesco) which used impulses transmitted by a column of liquid instead of a mechanical system of linkages. For the mechanical technology see Hydraulic machinery and Hydraulic cylinder Hydraulics is a topic of science and Engineering Romania ( dated: Rumania, Roumania This was not only inherently more reliable, but delivered firing impulses at a much higher rate, so that a synchronised gun now fired at more or less the same rate as a normal machine gun, regardless of engine revolutions. The gear could also be easily fitted to any type of aircraft instead of having to have type-specific linkages designed. The Constantinesco gear remained in use with the Royal Air Force until the Second World War, the Gloster Gladiator being the last British fighter to be equipped with it. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout

A pilot would usually only have the target in his sights for a fleeting moment so a concentration of bullets was vital for achieving a kill. The obvious solution was to increase the number of guns. The final version of the Fokker Eindecker, the Fokker E.IV, came with two Spandau machine guns and this became the standard armament for all the German D-type scouts starting with the Albatros D.I. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout The Maschinengewehr 08, or MG08, was the German Army 's standard Machine gun in World War I and is an almost direct copy of Hiram S The Idflieg designation system was used to generate German Military aircraft designations prior to the end of World War I. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout Fokker experimented with mounting three machine guns on the E. IV but the extra weight rendered the aircraft virtually unflyable. The Allies did not field an aircraft with twin synchronized guns until the Sopwith Camel and the SPAD S.XIII came into service (mid 1917). WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout

Turrets

With the introduction of the "high speed" bomber came a need to protect the gunner from the elements and to give protection but retain the wide firing arcs and so the power driven multi-gun turret evolved. One of the first instances was the single nose mounted turret of the Boulton Paul Overstrand that served with the RAF, and the almost simultaneous introduction of the much more advanced Martin B-10 with the US Army Air Corps. The Boulton Paul P75 Overstrand was the last of the twin-engine Biplane Medium bombers of the Royal Air Force, a series that had begun during the First WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout

For maximum efficiency the bomber turret needed to be able to rotate in all directions and cover as wide a range of elevation as possible - this meant that there would be some combinations of elevation and direction where the turret was aiming at some part of the aircraft itself. To prevent the guns firing an electrical system was used. The guns were fired by solenoids and by introducing a break in the electrical power to the guns that coincided with the forbidden arcs of fire the aircraft would be safe from its own guns. A solenoid is a three-dimensional Coil. In Physics, the term solenoid refers to a loop of wire often wrapped around a Metallic core which The Boulton Paul design used a brass drum and brush contacts that corresponded to the direction of the turret and angle of the guns. Boulton Paul Aircraft Ltd was a British aircraft manufacturer that was created in 1934 although its origins lay in 1914, and lasted until 1961. Where the brass was removed and replaced with insulating material the electrical circuit would be broken and the guns prevented from firing.

The End of Synchronization

The need for synchronization gears finally disappeared altogether when jets replaced propeller-driven fighters - but their use, even in piston engined aircraft, had already declined - especially after 1940. specific --->A jet engine is a Reaction engine that discharges a fast moving jet of Fluid to It was no longer practicable to mount guns with their firing mechanisms within the cockpit, which eliminated one of the reasons for having guns mounted in the fuselage in the first place. The importance of locating the guns in front of the pilot also diminished, as aircraft gunsight technology improved and the requirement for heavier armament increased. Cantilever monoplane wings provided much more space than the fuselage to mount armament - and being much more rigid than the old cable braced wings they provided a much steadier mounting. The result was that many fighters of the World War II era had all their guns mounted in the wings outside the propeller disc - their direction of fire "harmonised" to converge at a preset distance. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including Nevertheless, German and Soviet fighter types in particular were slow to abandon fuselage-mounted guns, usually in addition to wing mounted guns.

The last synchronizer-equipped aircraft to see combat action were the Lavochkin La-11 and the Yakovlev Yak-9 during the Korean War. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout The Korean War refers to a period of military conflict between North Korean and South Korean regimes with major hostilities lasting from June 25 1950 until the

References

• Woodman, Harry, "CC Gun Synchronisation Gear", Aeroplane Monthly, September 2005
• Jarrett, Phillip, "The Fokker Eindeckers", Aeroplane Monthly, December 2004
• "The Electro-Hydraulic Turret", The Aeroplane No: 1654, February 1943