GAU-8 Avenger
GAU-8/A Avenger | |
---|---|
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 |
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 very powerful rounds at a high rate of fire. The GAU-8/A is also used in the Goalkeeper CIWS ship weapon system, which provides defense against short-range threats such as highly maneuverable missiles, aircraft, and fast-maneuvering surface vessels. The GAU-8/A is produced by General Dynamics.
History
The GAU-8 was created as a parallel program with the A-X (or Attack Experimental) competition that produced the A-10. The specification for the cannon was laid out in 1970,
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 GAU-8.[7]
The A-10 with its GAU-8/A gun entered service in 1977. It was produced by
Design
The GAU-8 itself weighs 620 pounds (280 kg), but the complete weapon, with feed system and drum, weighs 4,029 pounds (1,828 kg) with a maximum ammunition load. It measures 19 ft 5+1⁄2 in (5.931 m) from the muzzle to the rearmost point of the ammunition system, and the ammunition drum alone is 34.5 inches (88 cm) in diameter and 71.5 inches (1.82 m) long.
The standard ammunition mixture for anti-armor use is a five-to-one mix of PGU-14/B
An innovation in the design of the GAU-8/A ammunition is the use of aluminum alloy cases in place of the traditional steel or brass.[13] This alone adds 30% to ammunition capacity for a given weight. The projectiles incorporate a plastic driving band to improve barrel life. The cartridges measure 11.4 inches (290 mm) in length and weigh 1.53 pounds (0.69 kg) or more.[8][13]
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
The GAU-8/A ammunition feed is linkless, reducing weight and avoiding a great deal of potential for jamming. The feed system is double-ended, allowing the spent casings to be returned to the ammunition drum.[15] Additionally, returning empty cases to the drum has less effect on the aircraft's center of gravity than ejecting them. The feed system is based on that developed for later M61 installations, but uses more advanced design techniques and materials throughout, to save weight.[8]
Firing system
Accuracy
The GAU-8/A is extremely accurate and can fire up to 3,900 rounds per minute without complications. The 30-mm shell has twice the range, half the time to target, and three times the mass of projectiles fired by guns mounted in comparable close air support aircraft.[16]
While the GAU-8/A has a muzzle velocity that is comparable to that of the M61 Vulcan, it uses heavier ammunition and has superior ballistics. The time of flight of its projectile to 4,000 feet (1,200 m) is 30 percent less than that of an M61 round; the GAU-8/A projectile decelerates much less after leaving the barrel, and it drops a negligible amount, about 10 feet (3.0 m) over the distance.[17] The GAU-8/A precision when installed in the A-10 is rated at "5 mil, 80 percent", meaning that 80 percent of rounds fired will hit within a cone with an angle of five milliradians; this equates to a 40-foot (12-meter) diameter circle at the weapon's design range of 4,000 feet (1,200 m).[18] By comparison, the M61 has an 8-milliradian dispersion.[13]
Recoil
Because the gun's
The GAU-8/A utilizes recoil adapters. They are the interface between the gun housing and the gun mount. By absorbing (in compression) the recoil forces, they spread the time of the recoil impulse and counter recoil energy transmitted to the supporting structure when the gun is fired.
The A-10 engines were initially susceptible to flameout when subjected to gases generated in the firing of the gun. When the GAU-8 is being fired, the smoke from the gun can make the engines stop, and this did occur during initial flight testing.[4] Gun exhaust is essentially oxygen-free, and is capable of causing flameouts of gas turbines. The A-10 engines now have a self-sustaining combustion section. When the gun is fired, the igniters come on to reduce the possibility of a flameout.[20]
The average recoil force of the GAU-8/A is 10,000
Variants
Some of the GAU-8/A technology has been transferred into the smaller 25 mm
Specifications
- 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
- PGU-14/B API
- 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
- Gryazev-Shipunov GSh-6-30
- List of aircraft weapons
- List of multiple-barrel firearms
- T249 Vigilante
- Type 730 CIWS
References
- ^ https://apps.dtic.mil/sti/pdfs/ADB028651.pdf. Archived (PDF) from the original on February 16, 2022.
{{cite web}}
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(help) - ^ 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 "GAU-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.
- ^ 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 GAU-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
- ^ "GAU-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 GAU-8 Avenger". Archived from the original on 2013-01-05.
- ^ a b "Fact Sheet: General Electric GAU-8/A "Avenger" 30mm Cannon". Hill Air Force Base. Archived from the original on 2011-06-04.
- ^ "GAU-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.
- ^ "GAU-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.
- ^ 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.
{{cite web}}
: Missing or empty|title=
(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
- Spick, Michael. The Great Book of Modern Warplanes, Salamander Books, 2000. ISBN 1-84065-156-3.