Propeller-coordinated machine gun

The invention: A mechanism that synchronized machine gun fire

with propeller movement to prevent World War I fighter plane

pilots from shooting off their own propellers during combat.

The people behind the invention:

Anthony Herman Gerard Fokker (1890-1939), a Dutch-born

American entrepreneur, pilot, aircraft designer, and

manufacturer

Roland Garros (1888-1918), a French aviator

Max Immelmann (1890-1916), a German aviator

Raymond Saulnier (1881-1964), a French aircraft designer and

manufacturer

French Innovation

The first true aerial combat ofWorldWar I took place in 1915. Before

then, weapons attached to airplanes were inadequate for any

real combat work. Hand-held weapons and clumsily mounted machine

guns were used by pilots and crew members in attempts to

convert their observation planes into fighters. On April 1, 1915, this

situation changed. From an airfield near Dunkerque, France, a

French airman, Lieutenant Roland Garros, took off in an airplane

equipped with a device that would make his plane the most feared

weapon in the air at that time.

During a visit to Paris, Garros met with Raymond Saulnier, a French

aircraft designer. In April of 1914, Saulnier had applied for a patent on

a device that mechanically linked the trigger of a machine

gun to a cam

on the engine shaft. Theoretically, such an assembly would allow the

gun to fire between the moving blades of the propeller. Unfortunately,

the available machine gun Saulnier used to test his device was a

Hotchkiss gun, which tended to fire at an uneven rate. On Garros’s arrival,

Saulnier showed him a new invention: a steel deflector shield

that, when fastened to the propeller, would deflect the small percentage

of mistimed bullets that would otherwise destroy the blade.

The first test-firing was a disaster, shooting the propeller off and

destroying the fuselage. Modifications were made to the deflector

braces, streamlining its form into a wedge shape with gutterchannels

for deflected bullets. The invention was attached to a

Morane-Saulnier monoplane, and on April 1, Garros took off alone

toward the German lines. Success was immediate. Garros shot

down a German observation plane that morning. During the next

two weeks, Garros shot down five more German aircraft.

German Luck

The German high command, frantic over the effectiveness of the

French “secret weapon,” sent out spies to try to steal the secret and

also ordered engineers to develop a similar weapon. Luck was with

them. On April 18, 1915, despite warnings by his superiors not to fly

over enemy-held territory, Garros was forced to crash-land behind

German lines with engine trouble. Before he could destroy his aircraft,

Garros and his plane were captured by German troops. The secret

weapon was revealed.

The Germans were ecstatic about the opportunity to examine

the new French weapon. Unlike the French, the Germans had the

first air-cooled machine gun, the Parabellum, which shot continuous

bands of one hundred bullets and was reliable enough to be

adapted to a timing mechanism.

In May of 1915, Anthony Herman Gerard Fokker was shown

Garros’s captured plane and was ordered to copy the idea. Instead,

Fokker and his assistant designed a new firing system. It is unclear

whether Fokker and his team were already working on a synchronizer

or to what extent they knew of Saulnier’s previous work in

France.Within several days, however, they had constructed a working

prototype and attached it to a Fokker Eindecker 1 airplane. The

design consisted of a simple linkage of cams and push-rods connected

to the oil-pump drive of an Oberursel engine and the trigger

of a Parabellum machine gun. The firing of the gun had to be timed

precisely to fire its six hundred rounds per minute between the

twelve-hundred-revolutions-per-minute propeller blades.

Fokker took his invention to Doberitz air base, and after a series of exhausting trials before the German high command, both on the

ground and in the air, he was allowed to take two prototypes of the

machine-gun-mounted airplanes to Douai in German-held France.

At Douai, two German pilots crowded into the cockpit with Fokker

and were given demonstrations of the plane’s capabilities. The airmen

were Oswald Boelcke, a test pilot and veteran of forty reconnaissance

missions, and Max Immelmann, a young, skillful aviator

who was assigned to the front.

When the first combat-ready versions of Fokker’s Eindecker 1

were delivered to the front lines, one was assigned to Boelcke, the

other to Immelmann. On August 1, 1915, with their aerodrome under attack from nine English bombers, Boelcke and Immelmann

manned their aircraft and attacked. Boelcke’s gun jammed, and he

was forced to cut off his attack and return to the aerodrome. Immelmann,

however, succeeded in shooting down one of the bombers

with his synchronized machine gun. It was the first victory credited

to the Fokker-designed weapon system.

Impact

At the outbreak of World War I, military strategists and commanders

on both sides saw the wartime function of airplanes as a

means to supply intelligence information behind enemy lines or as

airborne artillery spotting platforms. As the war progressed and aircraft

flew more or less freely across the trenches, providing vital information

to both armies, it became apparent to ground commanders

that while it was important to obtain intelligence on enemy

movements, it was important also to deny the enemy similar information.

Early in the war, the French used airplanes as strategic bombing

platforms. As both armies began to use their air forces for strategic

bombing of troops, railways, ports, and airfields, it became evident

that aircraft would have to be employed against enemy aircraft to

prevent reconnaissance and bombing raids.

With the invention of the synchronized forward-firing machine

gun, pilots could use their aircraft as attack weapons. Apilot finally

could coordinate control of his aircraft and his armaments with

maximum efficiency. This conversion of aircraft from nearly passive

observation platforms to attack fighters is the single greatest innovation

in the history of aerial warfare. The development of fighter

aircraft forced a change in military strategy, tactics, and logistics and

ushered in the era of modern warfare. Fighter planes are responsible

for the battle-tested military adage: Whoever controls the sky controls

the battlefield.