Machine Gun for close air dog fight
JF-17 Thunder,GSh-23-2 twin-barrel Cannon.
Cannons were considered obsolete in the late 60's after the advent of A2A missiles.. but humbling lessons in Vietnam proved otherwise. Today with the advancement in missile tech people are again considering the usefulness of cannons in A2A combat.
However.. in the current scenario of asymmetric threats.. the cannons have proved very useful in the A2G role as well.
traditional A2A fighters such as the F-15C can also provide a show of force by strafing with their cannon.
And many sorties against the taliban ended up being conducted with strafing runs after going Winchester on other ordnance.
Two or three cannons is debatable on the need for firepower.
A single 20mm cannon is enough to tackle most A2A threats.
Dual 30mm cannons are more suited to handling larger aircraft.
The accuracy of the cannons matters as well as ammo capacity.
Russian jets like the Fulcrum and Flanker carrry much less ammo for their cannons than western counterparts.. much they claim to have much better accuracy than the former.
GSh-23L_cannon
The
Gryazev-Shipunov GSh-23 (
Russian: ГШ-23) is a twin-barreled 23 mm
autocannon developed in the
Soviet Union, primarily for
military aircraft use. It entered service in 1965, replacing the earlier
Nudelman-Rikhter NR-23 cannon.
GSh-23 displayed in the
Egyptian Military museum
The GSh-23 works on the
Gast Gun principle developed by
German engineer
Karl Gast of the
Vorwerk company in 1916. It is a twin-barreled weapon in which the firing action of one barrel operates the mechanism of the other. It provides a much faster rate of fire for lower mechanical wear than a single-barrel weapon.
Although it cannot match the sustained rate of fire of an electric
Gatling gun like the
M61 Vulcan GAU, because it doesn't need to spool up, its initial rate of fire is higher. It requires no external power source to operate, but is instead powered by the recoiling of the floating barrels, somewhat like the action of the German MG-42. The Gast principle has been little used in the West, but was popular in the former
Soviet Union on a variety of weapons. It is reported to be a very reliable, robust weapon easily maintained in the field.[
citation needed]
The cannon comes in a basic GSh-23 variant, and the more popular GSh-23L (ГШ-23Л), differing mostly in adding a
muzzle brake, lowering
recoil force. This cannon was standard fit on late-model
MiG-21 fighters (M, SM, MF, SMT, bis), all variants of the
MiG-23, the
SOKO J-22 Orao, the
HAL Tejas and
IAR 93, and the tail turrets of the
Tupolev Tu-22M bomber and some late-model
Tu-95s. In that application, it had the unusual ability to fire infrared
flares and
chaff rounds, allowing it to function as both a weapon and a dispenser of anti-missile countermeasures. It is also mounted on late small series
Mi-24VP helicopters (in the NPPU-23 movable mounting) and Polish
W-3WA Sokół helicopter in fixed mounting. The cannon was also used on cargo aircraft; specifically, Russian/Soviet
Ilyushin Il-76 aircraft were designed to accommodate twin Gsh-23L's in a tail turret.
[1] An
Il-76M with just such a configuration could be seen at the 2002 Ivanovo airshow.
[2]
Some 2nd generation MiG-21 models could carry the GSh-23L in an under-fuselage gondola designated the
GP-9, carrying the cannon and 200 rounds of ammunition; this was replaced by a more streamlined semi-conformal installation in later variants. There are also several
gun pods available for mounting on external hardpoints:
UPK-23 for air-to-air use, with one or two fixed GSh-23 guns and 200-400 rounds of ammunition, and
SPPU-22 pods with traversable barrels for strafing, from 0° to −30° and carried 280 rounds of ammunition in each (they were most often carried by the
Su-17/-20/-22 as well as the
Su-25/-39 in pairs).