The General Electric GAU-8/A Avenger is a 30 mm hydraulically driven seven-barrel Gatling-style autocannon that is primarily mounted in the United States Air Force's Fairchild Republic A-10 Thunderbolt II. Designed to destroy a wide variety of ground targets, the Avenger delivers 30mm rounds at a high rate of fire. The G
GAU-8/A Avenger | |
---|---|
Type | Gatling-style autocannon |
Place of origin | United States |
Service history | |
In service | since 1977 |
Used by | United States Air Force (Avenger) Various navies (Goalkeeper) |
Production history | |
Designer | General Electric |
Manufacturer | General Electric General Dynamics |
Produced | since 1977 |
Variants | GAU-12/U Equalizer GAU-13/A |
Specifications | |
Mass | 619.5 lb (281 kg) |
Length | 19 ft 10.5 in (6.06 m) (total system) 112.28 in (2.85 m) (gun only) |
Barrel length | 90.5 in (2.30 m) |
Width | 17.2 in (0.437 m) (barrels only) |
Cartridge | 30×173 mm |
Caliber | 30 mm |
Barrels | 7-barrel (progressive RH parabolic twist, 24 grooves)[1] |
Action | Electrically controlled, hydraulic-driven |
Rate of fire | 3,900 rpm (variable)[2][3] |
Muzzle velocity | 3,324 ft/s (1,010 m/s) (API) |
Effective firing range | 4,000 feet (1,220 m) |
Maximum firing range | Over 12,000 feet (3,660 m) |
Feed system | Linkless feed system |
History
editThe G
The gun is mounted slightly to the port side with the active firing cannon barrel on the starboard side at the 9 o'clock position and on the aircraft's center line. The front landing gear is positioned to the starboard side.[6] The gun is loaded using Syn-Tech's linked tube carrier GFU-8/E 30 mm Ammunition Loading Assembly cart. This vehicle is unique to the A-10 and the G
The A-10 with its G
Design
editThe G
The standard ammunition mixture for anti-armor use is a five-to-one mix of PGU-14/B Armor Piercing Incendiary, with a projectile weight of about 14.0 oz (395 grams or 6,096 grains) and PGU-13/B High Explosive Incendiary (HEI) rounds, with a projectile weight of about 13.3 oz (378 grams or 5,833 grains).[10] The PGU-14/B's projectile incorporates a lightweight aluminum body, cast around a smaller caliber depleted uranium penetrating core.[11] In 1979, the Avenger was tested against M47 Patton tanks and caused "severe damage".[12]
An innovation in the design of the G
The Avenger's rate of fire was originally selectable, 2,100 rounds per minute (rpm) in the low setting, or 4,200 rpm in the high setting.[2] This rate was later changed to a fixed rate of 3,900 rpm.[3] At this speed it would take 18 seconds of sustained fire to empty the magazine. In practice, the cannon is limited to one and two-second bursts to avoid overheating and conserve ammunition; barrel life is also a factor, since the USAF has specified a minimum life of at least 20,000 rounds for each set of barrels.[14] There is no technical limitation on the duration the gun may be continuously fired, and a pilot could potentially expend the entire ammunition load in a single burst with no damage or ill effects to the weapons system itself. However, this constant rate of fire would shorten the barrel life considerably and require added barrel inspections and result in shorter intervals between replacement.
Each barrel is a very simple non-automatic design having its own breech and bolt. Like the original Gatling gun, the entire firing cycle is actuated by cams and powered by the rotation of the barrels.[13] The seven-barrel carriage assembly itself is driven by the aircraft's dual hydraulic system.[14]
The G
Firing system
editAccuracy
editThe G
While the G
Recoil
editBecause the gun's recoil forces could push the entire plane off target during firing, the weapon is mounted laterally off-center, slightly to the port side of the fuselage centerline, with the active firing barrel lying directly on the aircraft's centerline.[6] The firing barrel also lies just below the aircraft's center of gravity, being bore-sighted along a line 2 degrees below the aircraft's line of flight. This arrangement accurately centers the recoil forces, preventing changes in aircraft pitch or yaw when fired. This configuration also leaves space for the front landing gear, which is mounted slightly off-center on the starboard side of the nose.[19]
The G
The A-10 engines were initially susceptible to flameout when subjected to gases generated in the firing of the gun. When the G
The average recoil force of the G
Variants
editSome of the G
Specifications
edit- Precision: 80% of rounds fired at 4,000 feet (1,200 m) range hit within a 40-foot (12 m) diameter circle.[a]
- Ammo:
- PGU-14/B API Armor Piercing Incendiary (DU)
- PGU-13/B HEI High explosive incendiary
- PGU-15/B TP Target Practice
- Armor penetration of Armor-Piercing Incendiary ammunition, BHN-300 RHA, attack angle 30 degrees from vertical:[24]
- 76 mm at 300 meters
- 69 mm at 600 m
- 64 mm at 800 m
- 59 mm at 1,000 m
- 55 mm at 1,220 m
See also
editReferences
edit- ^ "G
AU -8V'GUN BARREL RIFLING DEVELOPMENT" (PDF). Archived (PDF) from the original on February 16, 2022. - ^ a b Stephens, Rick (1995). A-10 Thunderbolt II. World Air Power Journal. p. 18. ISBN 1-874023-54-9.
- ^ a b Time Compliance Technical Order 1A-10-1089, Flight manual TO 1A-10A-1. Vol. 1-150A (Change 8 ed.). United States Air Force. 20 February 2003. p. vi.
- ^ a b "G
AU -8/A Avenger". National Museum of the USAF. Archived from the original on 2010-04-16. Retrieved 2009-09-14. - ^ a b c Goebel, Greg (October 1, 2008). "A-10: Development & Description". Archived from the original on 2009-09-25. Retrieved 2009-09-14.
- ^ a b Donald, David and Daniel J. March, eds. "A-10 Fighting Warthog", p. 20. Modern Battlefield Warplanes. Norwalk, Connecticut: AIRtime, 2004. ISBN 1-880588-76-5.
- ^ "Turrets & Mounted Weaponry". Zombie survival wiki. Archived from the original on 2009-03-27. Retrieved 2009-09-14.[verification needed]
- ^ a b c d Spick 2000, p. 44.
- ^ "30 mm G
AU -8/A Ammunition" (PDF), Defense Systems, Orbital ATK, p. 2, November 2002, archived (PDF) from the original on 2017-02-07, retrieved 2016-05-18 - ^ "G
AU -8/A Ammunition (30 mm)". ATK. Archived from the original on 2014-01-09. Retrieved 2014-01-09. - ^ Stravonski. "Firepower of the A-10". Archived from the original on 2003-04-15. Retrieved 2009-09-14.
- ^ "A-1O/GAU-8 Low Angle Firing versus Simulated Soviet Tank Company" (PDF). DTIC. June 1980. Archived (PDF) from the original on 2016-03-04. Retrieved 2016-01-25.
- ^ a b c d Wagner, Jirka. "30mm cannon G
AU -8 Avenger". Archived from the original on 2013-01-05. - ^ a b "Fact Sheet: General Electric G
AU -8/A "Avenger" 30mm Cannon". Hill Air Force Base. Archived from the original on 2011-06-04. - ^ "G
AU -8 Avenger". Archived from the original on 2005-02-19. Retrieved 2005-04-27. - ^ "A-10/OA-10 Thunderbolt II history". Military systems. Global Security. Archived from the original on 2008-05-16. Retrieved 2008-05-26.
- ^ Jenkins 1998, pp. 64–73.
- ^ "G
AU -8 Avenger". FAS. Archived from the original on 2009-07-14. Retrieved 2009-09-14. - ^ "A-10 Described: GAU-8 Cannon / External Stores". Vectorsite. Archived from the original on 2008-12-25. Retrieved 2008-10-01.
- ^ a b Jenkins, Dennis R (1998). Fairchild-Republic A/OA-10 Warthog. North Branch, Minnesota: Specialty Press. ISBN 1-58007-013-2.
- ^ "Armament Systems: Aircraft Gun Systems". General Dynamics Armament and Technical Products. Archived from the original on 6 March 2014. Retrieved 6 March 2014.
- ^ "TF34 Engine". Global Security. Archived from the original on 2009-09-06. Retrieved 2009-09-14.
- ^ dtic.mil http://apps.dtic.mil/dtic/tr/fulltext/u2/a522397.pdf. Archived (PDF) from the original on 4 March 2016. Retrieved 2022-04-03.
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(help) - ^ Zecevic, Berko; Terzic, Jasmin; Catovic, Alan; Serdarevic-Kadic, Sabina (April 21, 2010), Dispersion of PGU-14 ammunition during air strikes by combat aircraft A-10 near urban areas, Sarajevo, Bosnia and Herzegovina: University of Sarajevo, Mechanical Engineering Faculty, p. 80.
Bibliography
edit- Spick, Michael. The Great Book of Modern Warplanes, Salamander Books, 2000. ISBN 1-84065-156-3.