M39 cannon
The
Pontiac M39 was a 20 mm
revolver cannon developed for the
United States Air Force in the late
1940s. It was used on a number of
fighter aircraft from the early
1950s through the
1970s.
The M39 was developed by the
Springfield Armory, based on the
World War II-era design of the
German Mauser MG 213, a 20 mm (and 30 mm) cannon developed for the
Luftwaffe, but not used in combat. The same design inspired the
British ADEN cannon and the French
DEFA, but American designers chose a smaller 20 mm round to increase the weapon's rate of fire and
muzzle velocity at the expense of hitting power.
Initially designated the
T-160, the new gun was installed for combat testing on a number of
F-86 Sabre aircraft under the "Gunval" program in late
1952, and used in action over
Korea in early
1953. It was subsequently adopted as standard armament of the
F-86H fighter-bomber,
F-100 Super Sabre,
F-101A and F-101C Voodoo, and the
F-5 Freedom Fighter. Current models of the F-5 Tiger II still use the
M39A2 version of this weapon, with 280 rounds per gun in single-seat models and 140 rounds per gun in two-seat aircraft.
The M39 is
not the same as the Hispano M3 derivatives used by the Navy (as the M3 and the later
Colt Mk 12 cannon) on aircraft like the
A-4 Skyhawk and
F-8 Crusader, nor the Hispano-derived M24 used by some
USAF aircraft of the late
1940s.
*
Type: single-barrel
automatic cannon*
Caliber: 20 mm x 102 (0.79 in)
*
Operation:
five-chamber revolver*
Length: N/A
*
Weight (complete): 81 kg (178.5 lb)
*
Rate of fire: 1,500 rpm
*
Muzzle velocity: 1,030 m/s (3,300 ft/s
*
Projectile weight: 101 g (3.56 oz)
