Engine gun

An engine gun, or engine cannon (from German: Motorkanone, "motor cannon"), is an aircraft gun mounted behind and through the cylinder block of an inline aircraft engine (most often a V engine) with a reduction drive that displaces the propeller axle to be in line with the gun so that gunfire is allowed through the propeller hub. This allows for nose-mounted weaponry on aircraft without the need for synchronization gear while also permitting higher calibers for nose-mounted weaponry, which otherwise would be hard to adapt for synchronization gear.^[1]

The first time this was done was during World War I when the French modified the Hispano-Suiza 8 engine to be able to install a 37 mm autocannon.^[2] The concept was used widely before the Jet Age.

Historical engine guns

Finnish guns

12.7 mm VKT 12,70 LKk/42 (single use on a Morane-Saulnier MS.406)

French guns

7.5 mm MAC 1934
20 mm Hispano-Suiza HS.404
37 mm SAMC (Semi Automatique Moteur Canon)

German guns

Soviet guns

Swiss guns

20 mm Oerlikon FF

Engine gun installations

French engines

Hispano-Suiza 8 (various models)
Hispano-Suiza 12Y

German engines

Soviet engines

Swiss engines

Aircraft with engine guns

Czechoslovak aircraft

Czechoslovak Avia Bk-534, a biplane with a 20 mm engine gun

Finnish aircraft

Mörkö Morane

French aircraft

German aircraft

Italian aircraft

Soviet aircraft

Swedish aircraft

SAAB 23

Swiss aircraft

Yugoslavian aircraft

References

^ "PART V AUTOMATIC AIRCRAFT CANNON". ibiblio.org. Retrieved 2025-05-18.
^ Thorsson, Nils (1975). Historik och kartläggning av vapenmateriel för flygplan. Arboga, Sweden. p. 25.{{cite book}}: CS1 maint: location missing publisher (link)