In World War I, aircraft were initially intended for aerial reconnaissance, however some pilots began to carry rifles in case they spotted enemy planes.
Soon, planes were fitted with machine guns with a variety of mountings; initially the only guns were carried in the rear cockpit supplying defensive fire (this was employed by two-seat aircraft all through the war).
Seeing a need for offensive fire, forward-firing weapons were devised.
The Airco DH.2 pusher plane had its gun in the front while the engine was in the back, some experimented with mountings on the (side) wing or on the biplane’s upper wing (above the cockpit), until by 1916 most fighter aircraft mounted their guns in the forward fuselage using a synchronization gear so that the bullets did not strike the propeller.
In World War II, fighter aircraft carried machine guns and cannons mounted in the wings, engine cowlings, nose, or between the banks of the engine, firing through the propeller spinner.
Night fighters sometimes utilized guns firing upwards as well. Bombers typically carried from one to 14 flexible machine guns and/or autocannon as defensive armament, while certain types added fixed offensive guns as well.
While missiles are the primary armament since the early 1960s, the Vietnam War showed that guns still had a role to play and most fighters built since then are fitted with cannon (typically between 20 and 30 mm in caliber) as an adjunct to missiles.
Modern European fighter aircraft are usually equipped with the revolver cannon, whereas the United States and to some extent Russia generally favor the Gatling gun. The Gatling gun quickly became the weapon of choice for most air forces.
- ADEN cannon (UK)
- 20 mm Becker (Germany)
- Berezin B-20 (USSR)
- Berezin BS (USSR)
- Berezin UB (USSR)
- Bordkanone BK 3,7 cannon (37mm, a.k.a. 3,7 cm) (Germany)
- Bordkanone BK 5 cannon (50mm, a.k.a. 5 cm) (Germany)
- Bordkanone BK 7,5 cannon (75mm a.k.a. 7,5 cm) (Germany)
- Breda-SAFAT machine gun (Italy)
- Browning Model 1919 machine gun (United States)
- Colt Mk 12 cannon (United States)
- COW 37 mm gun (UK)
- DEFA cannon (France)
- GAU-7 cannon (United States)
- GAU-8 Avenger (United States)
- GAU-12 Equalizer (United States)
- GIAT 30 (France)
- Gryazev-Shipunov GSh-23L (Russia)
- Gryazev-Shipunov GSh-6-23 (Russia)
- Gryazev-Shipunov GSh-6-30 (Russia)
- Gryazev-Shipunov/Izhmash GSh-30-1 (Russia)
- Gryazev-Shipunov GSh-30-2 (Russia)
- Hispano 20 mm cannon (Switzerland)
- Ho-1/Ho-3 cannon (20mm) (Japanese Army)
- Ho-5 cannon (20mm)(Japanese army)
- Ho-103 machine gun (12.7mm) (Japanese army)
- Ho-155 cannon (30mm), (Japanese army)
- Ho-203 cannon (37mm) (Japanese army)
- Ho-204 cannon (37mm) (Japanese army)
- Ho-301 cannon (caseless 40mm) (Japanese army)
- Ho-401 cannon (57mm) (Japanese army)
- Ho-402 cannon (57mm) Japanese army)
- Lewis gun (USA/UK)
- M2 Browning machine gun (United States)
- M4 cannon (United States)
- M39 cannon (United States)
- M61 Vulcan (United States)
- M134 Minigun (United States)
- M197 Gatling gun (United States)
- MAC 1934 (France)
- Mauser BK-27 (Germany)
- Parabellum MG14 (Germany)
- MG 15 machine gun (Germany)
- MG 17 machine gun (Germany)
- MG 131 machine gun (Germany)
- MG 151 cannon (Germany)
- MG FF cannon (Germany)
- MK 103 cannon (Germany)
- MK 108 cannon (Germany)
- Nudelman-Suranov NS-23 (Russia)
- Schwarzlose MG M.07/12 (Austria-Hungary)
- Shipunov 2A42 (Russia)
- ShKAS machine gun (Russia)
- ShVAK cannon (Russia)
- Maschinengewehr 08 (Germany)
- Spandau machine gun (Germany)
- Semi Automatique Moteur Canon d’aviation (37mm) (France)
- 75 mm gun (US) (T13E1 / M5) (United States)
- Type 1 machine gun (7.92mm)(Japanese navy)
- Type 2 cannon (30mm) (Japanese navy)
- Type 2 machine gun (13mm) (Japanese navy)
- Type 3 machine gun (13.2mm) (Japanese navy)
- Type 5 cannon (30mm) (Japanese navy)
- Type 88 cannon (75mm) (Japanese army)
- Type 89 machine gun (7.7mm) (Japanese army)
- Type 92 machine gun (7.7mm) (Japanese navy)
- Type 97 machine gun (7.7mm) (Japanese navy)
- Type 98 machine gun (7.92mm) (Japanese army)
- Type 99 cannon (20mm) (Japanese navy)
- 1.59 inch Breech-Loading Vickers Q.F. Gun, Mk II (“Vickers-Crayford rocket gun”) (UK)
- Vickers machine gun (UK)
- Vickers K machine gun (UK)
- Vickers VGO (Vickers Gas-operated) (UK)
- Vickers S (UK)
- Volkov-Yartsev VYa-23 (USSR)
- Karabin maszynowy obserwatora wz.37 (PL)