In early
1916This is a list of aviation-related events from 1916:-January:*January 12 - German aces Max Immelmann and Oswald Boelcke, with 8 kills, are the first pilots awarded with Pour le Mérite...
Sergeant Foster of
No. 11 Squadron RFCNo. 11 or XI Squadron is a Royal Air Force squadron. The squadron operated the Tornado F3 until 2005 when it was disbanded. It was reactivated in 2006 to operate the Typhoon F2, receiving its first aircraft on 9 October 2006.-World War 1:No...
devised a sliding rail mounting for the upper wing
Lewis GunThe Lewis Gun is a World War I era light machine gun of American design that was perfected and most widely used by the forces of the British Empire. It was first used in combat in World War I, and continued in service with a number of armed forces all the way through to the end of the Korean War...
on a
Nieuport 11The Nieuport 11, often nicknamed the Bébé, was a French World War I single seat fighter aircraft, designed by Gustave Delage. It is famous as one of the aircraft that ended the 'Fokker Scourge' in 1916.-Design and development:...
. It enabled the gun to be pulled down so that its breech was conveniently in front of the pilot, making it much easier to change ammunition drums or to clear stoppages in flight. The mounting was readily adaptable to several other types of
biplaneA biplane is a fixed-wing aircraft with two main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...
fighter aircraftA fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets by dropping bombs. Fighters are small, fast, and maneuverable...
, including in particular the
Nieuport 17The Nieuport 17 was a French biplane fighter aircraft of World War I, manufactured by the Nieuport company.-Design and development:The type was a slightly larger development of the earlier Nieuport 11, and had a more powerful engine, larger wings, and a more refined structure in general...
and
24The Nieuport 24 was a French biplane fighter aircraft during World War I designed by Gustave Delage as a replacement for the successful Nieuport 17.-Design and Development:...
(in British service) and the
S.E.5aThe Royal Aircraft Factory S.E.5 was a British biplane fighter aircraft of the First World War. Although the first examples reached the Western Front before the Sopwith Camel, and it had a much better overall performance, problems with its Hispano-Suiza engine meant that there was a chronic...
, and became a standard fitting for these aircraft and others.
In early
1916This is a list of aviation-related events from 1916:-January:*January 12 - German aces Max Immelmann and Oswald Boelcke, with 8 kills, are the first pilots awarded with Pour le Mérite...
Sergeant Foster of
No. 11 Squadron RFCNo. 11 or XI Squadron is a Royal Air Force squadron. The squadron operated the Tornado F3 until 2005 when it was disbanded. It was reactivated in 2006 to operate the Typhoon F2, receiving its first aircraft on 9 October 2006.-World War 1:No...
devised a sliding rail mounting for the upper wing
Lewis GunThe Lewis Gun is a World War I era light machine gun of American design that was perfected and most widely used by the forces of the British Empire. It was first used in combat in World War I, and continued in service with a number of armed forces all the way through to the end of the Korean War...
on a
Nieuport 11The Nieuport 11, often nicknamed the Bébé, was a French World War I single seat fighter aircraft, designed by Gustave Delage. It is famous as one of the aircraft that ended the 'Fokker Scourge' in 1916.-Design and development:...
. It enabled the gun to be pulled down so that its breech was conveniently in front of the pilot, making it much easier to change ammunition drums or to clear stoppages in flight. The mounting was readily adaptable to several other types of
biplaneA biplane is a fixed-wing aircraft with two main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...
fighter aircraftA fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets by dropping bombs. Fighters are small, fast, and maneuverable...
, including in particular the
Nieuport 17The Nieuport 17 was a French biplane fighter aircraft of World War I, manufactured by the Nieuport company.-Design and development:The type was a slightly larger development of the earlier Nieuport 11, and had a more powerful engine, larger wings, and a more refined structure in general...
and
24The Nieuport 24 was a French biplane fighter aircraft during World War I designed by Gustave Delage as a replacement for the successful Nieuport 17.-Design and Development:...
(in British service) and the
S.E.5aThe Royal Aircraft Factory S.E.5 was a British biplane fighter aircraft of the First World War. Although the first examples reached the Western Front before the Sopwith Camel, and it had a much better overall performance, problems with its Hispano-Suiza engine meant that there was a chronic...
, and became a standard fitting for these aircraft and others.
Although possibly not part of the original intention the mounting allowed the Lewis gun to fire forwards and upwards, rather than straight ahead, to attack an enemy aircraft from behind and below, a favourite tactic of the ace
Albert BallAlbert Ball VC, DSO & Two Bars, MC was an English First World War fighter pilot and recipient of the Victoria Cross, the highest decoration for gallantry "in the face of the enemy" that can be awarded to members of the British or Commonwealth armed forces...
and a precursor of the
Schräge MusikSchräge Musik, derived from the German colloquialism for "Jazz Music" , was the name given to installations of upward-firing cannon mounted in night fighters by the Luftwaffe during World War II...
tactics used by German
night fighterA night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility.Night fighters came into their own during World War II, made possible with the advent of airborne radar. Prior to that, the main components of air defence at night were searchlights and anti-aircraft...
s in the
Second World WarWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
. When fired directly forwards, the trigger of the Lewis Gun was controlled by a
Bowden cableA bowden cable is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable relative to a hollow outer cable housing...
; when fired upwards the pistol grip was held to steady the weapon, and it was fired by pressing the trigger.
Twin Foster mountings were occasionally used, although the recoil and vibration of two Lewis guns firing simultaneously was considered a dangerous strain for the lightly-braced centre section of the aircraft of the time.
As the gun's line of fire was outside the
propellerA propeller is a type of fan which transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and air or water is accelerated behind the blade...
arc, Foster-mounted guns did not require
synchronisingAn interrupter gear is a device used on military aircraft and warships in order to allow them to target opponents without damaging themselves....
gear. The mounting could only be fitted to types with a suitable configuration, and was a little less stable and more subject to vibration than a mounting in the fuselage, resulting in a more widely spread pattern of fire.
The illustration shows a Foster mounting adapted to the
Avro 504The Avro 504 was a World War I biplane aircraft made by the Avro aircraft company and under licence by others. Production during the War totalled 8,970 and continued for almost 20 years, making it the most-produced aircraft of any kind that served in World War I, in any military capacity, during...
K night fighter. This aircraft had a much larger gap between the top of the fuselage and the upper wing than most types fitted with this type of mounting—in an S.E.5a for instance the gun was much more easily reached, and the mounting shorter and neater.