Talk:GAU-8 Avenger/Archive 1

Archive 1

Spinning

How are the barrels rotated? Electrical, hydraulic, gas-actuated? How long is typical spin-up time? --Andrew 09:57, Apr 11, 2005 (UTC)

Q. How are the barrels rotated?

A. The rotational force is delivered by two hydraulic drive motors operating off of both main aircraft hydraulic systems (A+B). The motors deliver their torque to a gearbox in the Hydraulic drive assembly. This in turn delivers the force to two drive shafts. The forward one goes to the rotor assembly on the GAU-8 itself, while the second delivers it's power to the ammunition drum.

Q. How long is typical spin-up time?

A. While the system is capable of operating at 4200 rounds per minute, it is limited to 3900 while installed in the aircraft. Since the GAU-8 has 7 barrels it needs to spin at 1/7th of the firing rate. Basically since it's rotating a touch over 550 rpm, the spin-up time is almost instantaneous.

On another point, the statement on the gun gas on affecting the engines is complete rubbish. During the firing of the GAU-8 the engines ingest so much gun gas that the engine igniters (think super spark plugs) must fire to ensure a stall does not occur. The engines also will ingest so much soot from the firings that they need to be "water washed" (have water and a mild cleaning solution misted into the engines while running at approx. 80% power) periodically to remove soot from the blades. Anyone who has had to clean an A-10 will tell you the gun gas goes just about everywhere aft of the nose.Fyoutoo (talk) 15:16, 6 July 2008 (UTC)

There is video from the early flight test days of the A-10 firing the gun, then actually stalling the engines as a result. They fixed the problem, but clearly the gasses do go everywhere. By the way, that same video shows the pilot ejecting since the engines would not restart after the shutdown. Ask USAF. It did happen. --22:47, 25 September 2006 (UTC)

Pilot comment: The engines ARE at full throttle during strafe at all angles up through 30 degrees of dive. In 45 degree high angle strafe, they are between stood up and slightly above idle, depending on atmospheric conditions; and in 60 degree strafe they are at idle, but in both of the latter cases, gravity is doing far more work on the aircraft than the gun possibly could. It is also true that the gun gasses would flame out the engine, thus fences were installed on the underside of the aircraft just forward of the wings to divert the gas, and it's true that the igniters fire anytime the trigger is pulled. As for spin-up time, it's almost instantaneous; 50 rounds are fired in the first second, as the gun spins up, but every second after that it fires at 70 rounds per second. The gun can operate even if one hydraulic system is lost, but at a slower rate. —Preceding unsigned comment added by 210.124.133.112 (talk) 15:05, 12 September 2008 (UTC)

How does a 30mm compare to a .50 calibre?

Which is more powerful?

Q. "Which is more powerful?"

A. The 30MM round is roughly double the diameter of the .50 cal round. The mass of the actual projectlile is roughly 22 times as much with a corresponding increase in powder. The GAU-8 is a large order of magnitude more powerfull than the GAU-18 (.50 cal weapon).Fyoutoo (talk) 15:17, 6 July 2008 (UTC)

(Also try it this way 30mm vs 12.7 mm)

Pop Culture References to the GAU-8 Avenger...

I am new to Wikipedia, but I must comment that the addendum to this article titled "Pop Culture References to the GAU-8 Avenger" really has deserves no merit for inclusion to this page. Quite frankly, it is poorly written and does not make sense. I ask if others share the same opinion.

I am changing it to ......

In Mark E. Roger's satirical graphic novel Samurai Cat, the GAU-8 Avenger has been featured as a weapon of choice by many characters, some with the ability to lift and fire immense weapon.

Information about production needs updating?

The page states that production was finished in the 1970s. However, the Goalkeeper CIWS states that it uses the gun in a point defense role. Would it be possible to determine whether these guns are newly-made, or at least update the page with details as to the weapons new usage? 58.28.149.143 02:58, 3 February 2007 (UTC)Reiver

Goalkeeper guns were new production. VTFirefly911 04:34, 27 October 2007 (UTC)

Strange claims of mass and size...

In the "History" section of this article, a rather extreme claim is made that "On the...A-10, the GAU-8 fills half of the aircraft fuselage and represents one third of its unladen weight."

This doesn't add up, given the numbers for weight and length of the GAU-8 in this article and the corresponding figures given for the A-10 in A-10 Thunderbolt II:

GAU-8:
weight of gun alone: 620 lbs
weight of gun, feed system, drum and max ammunition load: 4029 lbs
length of entire system: 19 feet

A-10:
empty weight: 24,959 lbs
length: 53 feet four inches

Given these numbers, the claim of the GAU-8 filling 50% of the aircraft volume and 33% of its empty weight is absurd. The GAU-8 is 228 inches long, which is only 35.6% of the A-10's 640 inches. Given that a gun is a denser piece of machinery than an aircraft and the aircraft is certainly wider than the gun system, a gun that is only 33.6% as long as its carrying aircraft is certainly not going to fill 50% of the aircraft's fuselage space.

Similarly, at 4029 lbs, a GAU-8 gun system with a full load of ammo is just a hair over 16% of the weight of an unloaded A-10, less than half of the 33% claimed in the article.

I've just now signed in around here, so I'm not going to delete the offending hyperbole myself, but I would think that a more experienced editor would be wise to do so. Molon Labe 22:42, 18 March 2007 (UTC)

Went ahead and edited the offending material. --Molon Labe 03:18, 26 March 2007 (UTC)

DU?

I deleted the brief and inaccurate commentary on DU in this article because it is covered in much greater detail and balence in the linked article on DU. The comments appeared to refer to the Basrah University leukemia study but do not represnt the prevailing scientific view that a link to DU is not proven. I retained the link that explains the controvery adequately. 12.10.223.247 01:41, 1 July 2007 (UTC)

Debunking the Avenger

Remember, The wepon is not as accurate as this says, it had a test with a similar target, and found out only 1% of the rounds hit, as they didn't find all the bullets the first time, another problem, it only packs less explosives then a M79 grenade, well expected, as M79 is 40mm. also, it is insanely unreliable, jamming every other second. it overheats at an obscene rate. also, it is not very durable. it is the sole reason the A-10 is being phased out, the USAF is too stupid to just replace the damn gun. —Preceding unsigned comment added by 71.112.199.78 (talk) 05:29, 30 September 2007 (UTC)

I also must add that i know several pilots of the A10, and they all hated the gun with a passion, but never complained about the aircraft itself. —Preceding unsigned comment added by 71.112.199.78 (talk) 05:40, 30 September 2007 (UTC)

Umm... what? You obviously have no idea what a real avenger does. Your probably under some dilliosion that a combat aircraft, designed with this gun and for the reason of using it, that has been in service for 30 odd years means that the craft is crap. A-10s are not being phased out, however there has been some scale back to the active fleet (they are still in near operational status, complete with gun), not pahsing out. I would also like to know if the pilots you are talking about are USAF, or xbox live, ace combat 6 is not an accurate representation of any combat aircraft or weapon (honestly, since when are such a large number of f-16s and 14s in formation, getting briefed in mid-air as opposed to on the ground where there aren't foxbats shooting at you).Dagorlad 3 (talk) 20:49, 8 February 2008 (UTC)

What??? You, debunker, (top 2 comments above) are talking out of your ass! I am an A-10 pilot, and like every other Hawg pilot in the USAF, I love the gun. It is lethal, accurate, and reliable. The bullet dispersion is better than 80% of the rounds within 2.5 milliradians from boresight. To visualize that, that is approximately a 20 foot dispersion when fired at 4,000 foot slant range. Aiming error with the integrated flight and fire control computer is better than 1 milliradian when the gun is boresighted properly, and at that range a 20 foot armored vehicle spans about 5 milliradians - meaning that for a 2 second, 120 round burst (50 rounds are fired in the first 1 second as the gun spins up, then 70 rounds per second after that), about 96 rounds will impact the target. The GAU-8 is the primary weapon on this aircraft and our weapon of choice when employing against armor or vehicles of any kind. NONE of the pilots of the A-10 hate the gun... that statement is absolute rubbish. Instead, it's the weapon we use when things turn ugly and the troops on the ground are in direct contact with the enemy. It does not "jam every other second" - of course like any piece of machinery, the gun will malfunction from time to time, and sometimes catastrophically, but not very often - I have fired thousands of rounds and have yet to encounter a malfunction other than an easily remedied spin-up firing delay, linked to a minor rounds counter malfunction during the clearing and cooling cycle. Nor will it overheat "at an obscene rate"... certainly the accuracy will decrease and the dispersion will increase during a long burst of greater than 2-3 seconds, due to barrel heating, but the entire drum of ammo (1174 rounds, reduced from the original 1352 due to drum helix redesign) can be expended in one burst without danger (it would be a colossal waste of ammo and would trash the barrels, however). Your comment about the ammunition being "weak because it has less explosive than an M79" shows serious lack of understanding of the kill mechanics and weapons effects of 30mm API and HEI combat mix. Seriously, ignorant comments like yours are the reason why Wikipedia has a bad reputation. —Preceding unsigned comment added by 210.124.133.112 (talk) 14:57, 12 September 2008 (UTC)

Debunking the debunking

I've been an Aircraft Armament System Specialist in the USAF for 18 years. I have 3 years working the A-10A, OA-10, and A-10C specifically in support of the fighter weapons school and 422 test and evaluation squadrons at Nellis AFB in Nevada. I suppose I am qualified to speak as an expert here.

On accuracy, it's true that aircraft cannons in general are not the most accurate weapons in the world; but 1% is hardly a true figure. I could see that if you used a little creative language about Mk1 eyeball targeting system, I supposed you could be right, but that is simply not the case. The continuously computed impact point in the HUD and the funnel makes the system useable at ranges exceeding 2 1/2 miles in slant range. I have seen good HUD footage of over 3 mile engagements. That would not be possible for as inaccurate weapon as you state.

I am not exactly sure what you are trying to accomplish to when you compare the ammunition explosive payload of the PGU ammo and the M79 grenades. The Gau-8 is primarily an anti armor/vehicle weapon where the M79 is primarily anti personnel weapon. In your combat-mix the DU penetrator is the prime round with the HEI mixed in only for it's secondary effect. In the anti-armor role the explosive payload of the secondary round is of minimal consequence. The prime effect of the weapon is generated by the kinetic effects of the DU, not any secondary explosive payload.

When it comes to reliability I cannot say that it's any better or worse than the M61A1 in the F-15 or F-16 (with the notable exception of the linear linkless system employed in the F-15E which is total crap). It is actually an easier system to troubleshoot and fix than the M61A1 because it has the ability to spin in both directions, not to mention the fact that the ground operation lever allows you to easily spin it hydraulically without having to enter the cockpit other than to operate the APU.

I have never seen a rotary cannon system overheat in my 18 years of fixing the things, nor have I ever heard of one doing so. On the durability issue it is removed every 18 months or 25,000 rounds for scheduled maintenance. This is a pretty standard maintenance schedule for a weapons system. With the exception of the barrels and certain wear susceptible parts the system itself is serviceable for a quarter of a million rounds. I would say that it's fairly durable.

I wouldn't say that the A-10 is getting phased out. The USAF is spending gobs of cash converting the fleet to the A-10C model. Seems like a silly thing to do if you are phasing it out. The Air Force is however changing it's mission with it's expanded capabilities.

While I can't speak about the personal experiences of your A-10 pilot friends. I have met more than a few pilots that have either instructed or learned at the weapons school or flown with the 422 test and eval squadron. Every one of them loves their ugly old Hog and the fact that they have the big honking gun. It's a matter of pride for every Hog driver I have met. Fyoutoo 02:09, 23 October 2007 (UTC)

- Not to mention that this gun's pretty much 'un-debunkable'. I mean, look at that motherfucker; I'm amazed that it can't do you serious harm in some way through it's photographs. It makes guys that drive MBTs soil their shreddies. Like, even when they're in the act of driving said MBT. —Preceding unsigned comment added by 198.53.213.190 (talk • contribs)

Rate of fire?

The rate of fire is listed as 4200RPM in the section about the recoil, but in the section immediately below it's listed as 3900RPM. Which of those is accurate?

"It is also said that this is to deal with the substantial deceleration of the plane that results from firing. This is however a myth (see below)."

That's a bit confusing. The plane *does* decelerate from firing the weapon, as the myth buster itself points out. The myth is actually that the plane would fly backwards/stop the plane. -- Moogleii 07:34, 10 December 2005 (UTC)

I agree here. It's ridiculous to assert that a reaction force equal to half the total maximum thrust of the engines wouldn't cause the aircraft to slow down. Chances are the engines are not at full throttle when the A-10 is nose down and firing its gun at tanks. If the airspeed is approximately constant before firing the gun, the thrust and drag are equal in magnitude. Suddenly adding 10,000 lbf in the drag direction by firing the gun would definitely cause the aircraft to lose airspeed. I recommend this section is changed so as not to perpetuate a physical impossibility--that is, unbalanced force with no acceleration.

" It is the largest (it is the size and weight of a family saloon car), heaviest and most powerful aircraft gun in the United States military."- What about the howitzer on the AC-130? --I think the logic is "gun intended for an aircraft", because the 105mm gun on the AC-130 is the old gun from the M1A1 Abrams.

In terms of total system weight and size, the GAU-8/A is larger both in volume and weight than the M102 105mm howitzer. --Falcon48x 23:27, 17 May 2006 (UTC)

- Okay. But I'd bet dollars to dohnuts that the Mark 7 16"/50 Caliber batteries found on the U.S.'s Iowa-Class Battlecruisers eclipse the GAU in this department. —Preceding unsigned comment added by 198.53.213.190 (talk) 13:36, 28 February 2008 (UTC)

Actually the average recoil force is found to be 44.5kN[1] These facts come from straight the producer; General Dynamics Armament and Technical Products (GDATP)--Mad Max 19:04, Nov 21, 2004 (UTC)

Tweaked the section about the myth further. While the product homepage states the recoil force at 44.5 kN, I think there is he possibility that they made an error when converting from Pounds to kN (if they did that). The measurment "10 000 Pounds" only holds one significant digit while 44.5kN holds three. I compromised by stating 45kN in the article. --J-Star 13:00, 2004 Nov 23 (UTC)

The USAF did actually experiment with a few ways to mitigate the effect of the recoil on the plane during during the 80's and 90's. One of these included extending the nose of plane to form a cowling around the end of the gun which acted as a muzzle brake (similar to that seen on large caliber sniper rifles/mobile artillery pieces). This was decided to be too expensive and too much effort for the effect it had. Also the reason the gun is mounted off the centreline of the plane is that the recoil forces are great enough that when they originally had the gun mounted on the centreline the recoil forces were actually enough to push the gun off target. This is because by the time the bullet leaves the barrel, the barrel it is being fired from is in the 9 o'clock position. Thus with the gun mounted on the centreline the recoil forces are off the centreline. --SgT_LemMinG 16:23, 2006 Dec (+10)

Pilot comment. They briefly experimented with a muzzle-mounted gun gas diverter (the Batelle diverter) and it marginally improved accuracy while reducing the amount of gun gas ingested by the engines, but it harmonically unbalanced the gun leading to cracks and failures in the bolts and longerons in the gun mount assembly, so it was abandoned. And yes, the bullet fires from the barrel in the 9 o'clock position, placing the recoil nominally through aircraft centerline. Finally (read my comment in the next section) from experience flying the aircraft and employing the gun, there is no appreciable deceleration of the aircraft while the gun is fired. The throttles are indeed at max when strafing at any angle from level to 30 degrees, and though they are pulled back to near idle at 45 or 60 degrees, gravity in those cases overpowers any recoil the gun may be imparting. Yes, we can employ the gun from 60 degrees of dive and 5,000 feet over the target... it feels like you are standing on the rudder pedals looking straight down. From low altitude, we'll shoot until we are at 2000 feet slant range; this is very close when you're going 350 knots and as low as 75 feet above the ground. The gun is generally fired at anywhere between 275 to 375 knots, and with the throttles at max (or the pitch at 45 to 60 degrees nose low) the aircraft continues to accelerate throughout the attack. The jet does not lose airspeed, but sure, its acceleration will be reduced slightly while the gun is shooting. —Preceding unsigned comment added by 210.124.133.112 (talk) 15:18, 12 September 2008 (UTC)

• • Firing in short bursts does not change air speed significantly, and firing in short bursts is all this gun can do. Its total ammo load is 17.25 seconds long. A short burst is all any target needs. All the time you'll have your sights on your target is only enough for a short burst. So the "doesn't decellerate" statement is innacurate from a physics theory standpoint, but accurate from the standpoint of the pilots and targets of this gun-with-wings. 63.111.142.98 (talk) 18:53, 10 May 2011 (UTC)

Disadvantage

isnt the main disadvantage of this weapon (compared to http://de.wikipedia.org/wiki/Mauser_BK-27 for example) that it needs some time to get running when the trigger is pulled? especially in combat situations where bursts are very short (<1 sec). this should be added. --Philtime (talk) 22:39, 16 March 2008 (UTC)

Shouldn't you be asking what the spin-up time is before you assume it's a "disadvatage"? (According to a post above, the spin-up time is practically instantaneous.) Also, how many rounds does the GAU-8 fire in each burst, how long is each burst, and how does this compare to the BK-27? Meaning in that one second, which weapons fires more rounds from the time the trigger is pulled to when the gun stops firing, and how many rounds are likely to hit a given target at the same range. Until we know the actual answers to those questions, and have sources to back them up, we have nothing to add to the arcticle except assumptions. PS, the English article is at Mauser BK-27, for those like myself who can't read German. It appears to be largely identical to the German article, at least in the specs. - BillCJ (talk) 22:58, 16 March 2008 (UTC)

did you oversee my "?" ?? i asked and didnt assume. the german page compares BK27 and M61: BK27 shoots 4 kilos of bullets in the first 0.5 sec and M61 2 kilos. M61 and Gau8 are similar, i concluded that there may be a disadvantage. what is the time for GAU8 to spin up? --Philtime (talk) 12:43, 17 March 2008 (UTC)

I guess this is really two questions.

1. What is it’s biggest disadvantage?

2. How does the gun stack up against the Mauser in the first ½ second of firing?

1. I honestly would say that the main disadvantage of the gun is it’s massive size and complexity. It takes a crew of 4 anywhere from 4-8 hours to install and test the massive beast. It is also such a complicated job that it requires two separate inspection by qualified master technicians to certify the installation. Have I ever installed a revolver type cannon? No , I honestly haven’t, but I spent the better part of 10 years installing rotary cannons and they are all complicated pieces of kit.

I do not believe that a lower initial firing rate during spin-up is that much of a issue when you are in an Air-to-Ground (AG) role as opposed to the Air-to-Air (AA) role. When used in an AA role guns needs to throw out as many projectiles in as little time as possible because of the speed of the target. The window of opportunity for a successful AA engagement with a gun is very small as modern aircraft can literally fly between the bullets. Ground targets however offer a very slow moving target relative to the aircraft. The aircraft has a longer opportunity to line up a shot and keep the stream of rounds on target longer.

Aircraft also have the ability to “walk” their rounds onto AG targets. “Walking" allows the aircraft to correct it’s stream of rounds onto a target and correct for inaccuracies from whatever source (Wind, faulty boresight, extreme range, etc.) . The initial ½ second of the burst is actually the least accurate part of the firing instance. The pilot will look at the initial rounds path an make minor corrections to the trajectory to put rounds on target for effect. By the time the pilot has made the initial corrections to targeting the rotary cannon is at it’s maximum firing rate.

2. Philtime brings up an interesting issue. How much projectile weight can the gun throw on a target during it’s spin up? I honestly have no concrete referenceable numbers but I think that we can use some simple assumptions to get a realistic range so that we have a frame of reference.

Philtime I am going to use your numbers as my basis for calculations if you don’t mind. For the first half second using your numbers the guns stack up like this

Mauser BK-27

260g projectile x 15.38 rounds in ½ second of firing = 4 Kg of rounds in the first half second of firing.

M61A1

100g projectile x 20 rounds in first ½ second of firing= 2 Kg of rounds in the first half second of firing.

For the Gau-8 I am going to make 2 calculations. In the first I am going to assume that the ROF during spin-up is 20% of the maximum firing rate similar to the M61A1. In the second I am going to assume that the spin-up firing rate is the same 20 rounds in the first ½ second like the M61A1. I will be using a projectile weight of 412g because the normal combat loadout uses a 4:1 ratio of API rounds (450g) to HE rounds (360g).

GAU-8

(20% of Max ROF) 412g projectile x 13 rounds in ½ second of firing = 5.356 Kg of rounds in the first 1/2second.

(20 rounds first 1/2 sec.) 412g projectile x 20 rounds in ½ second of firing = 8.240 Kg of rounds in first ½ second.

The Gau-8 should have a greater output of rounds in the first ½ second of firing over the Mauser BK-27 even when accounting for spin up. As soon as the GAU-8 is up to full ROF it will blow the Mauser out of the water by putting over 3½ times the projectiles by weight as Mauser at the same muzzle velocity. Fyoutoo (talk) 15:43, 12 April 2008 (UTC)

Is the GAU-8 only used in the A-10.

The GAU-8 is used in two applications; the A-10 aircraft and the Goalkeeper Close-in Weapon System. Although the basic gun is the same, the two applications use barrels of a slightly different design. VTFirefly911 (talk) 02:46, 18 August 2009 (UTC)

Recoil

Hi, I wanted to bring into question the "Recoil" section of the article. I'm not questioning the numbers provided (45kN of recoil force versus 82.6kN of engine force) or their sources, but what I find questionable is, what seems to me to be, the un-sourced conclusion, provided in that paragraph, that these numbers completely debunk the possibility of the "urban legends" being true. Obviously, the more outlandish ones (such as flying backwards) are made highly improbable by these facts, but the idea that prolonged firing of the gun could lead to the plane crashing is still, theoretically, possible. First of all, pilots flying the plane are unlikely to fly with the engines at 100% thrust all the time. Perhaps, they know to gun the engines before going in for a strafing run, but even with the engines at 100% thrust a recoil greater than 50% of the engine output will still slow the plane down significantly. Remember, the plane doesn't need to come to a complete stop in order to be at risk of crashing, it just needs to slow down below the stall speed in order to drop from the sky (or, potentially, become unstable when getting close to that speed). Of course, the straight wings imply a, relatively, slow stall speed but that's besides the point. My primary point is that there is no source that, actually, backs up this conclusion much less a source acceptable to Wikipedia's policies. At the very least, I'm sure some of the present and former Warthog pilots that seem to post in this discussion page should be able to provide more insight into the truth of the situation. Even if I had a source, one way or the other, I can't post as I don't have an account or the time to make one. I just wanted to bring this up. 12.32.89.121 (talk) 18:21, 3 September 2009 (UTC)

Reference to the size

"It is among the largest, heaviest and most powerful aircraft cannon in the United States military, and when the entire cannon with its drum-style ammunition magazine is considered, is the single largest forward-firing cannon ever fitted into an aircraft." I don not think that this is correct because during Vietnam the F-14 TomCat was mounted with a 35 millimeter cannon to peirce ground artilerary. I may be wrong but a 30 millimeter cannon IS very large and in my opinion is much to large for 'Dog Fighting' and is more that twice the size of a .50 calibur rifle. It IS large but stupidly there was something LARGER put on to the F-14 TomCat. Oh Btw the F-14 is one of the best fighters ever used in it's average kill rate. It would have been the best EVER (in my opinion) if the had used a 25 millimeter cannon. —Preceding unsigned comment added by 98.196.67.108 (talk) 15:28, 8 February 2010 (UTC)

Sounds like fiction. The F-14 used the 20 mm M61 Vulcan cannon, like all US fighters from circa 1960 until the F-35 (25 mm cannon). -Fnlayson (talk) 16:38, 8 February 2010 (UTC)

Ignoring weapons that were tested on USA aircraft, but not put into practice; I believe the biggest cannon ever carried by a military aircraft was the 75mm T13E1, which was manually loaded one round at a time and frequently carried by the B-25H Mitchell. It was good against pillboxs and small ships, but, too slow (and inaccurate) to be used as an effective anti-tank weapon. Also, the Lockheed AC-130 Hercules carries a 105mm M102 howitzer. It can probably take out tanks, although the AC-130 is probably much more vulnerable than the A-10.204.80.61.110 (talk) 17:57, 10 May 2010 (UTC)Bennett Turk

Is GlobalSecurity.org information correct?

Under the section "Firing system" - "Accuracy" is the following sentence: "The 30-mm shell has twice the range, half the time to target, and three times the mass of projectiles carried by comparable Close Air Support aircraft." That sentence is taken word for word from GlobalSecurity.org, and I'm not sure if GS is correct (though it could just be a case of poor phrasing). For example, Wikipedia's page on the Soviet GSh-6-30 indicates that it fired a 30x165mm round comparable in mass to the GAU-8's 30x173mm, with only a bit less muzzle velocity. While the GAU-8's definitely a more powerful system GSh-6-30, I'm not sure where x2 the range, 1/2 the ToT and x3 the mass is coming from. It sounds like GS is mistakenly comparing the GAU-8 with something in the 20mm range, rather than truly comparable systems in the 30mm range.

It seems like the quote from GS needs to have a caveat, or be replaced with a longer and more accurate comparison of the GAU vis-a-vis comparable systems. 99.236.184.57 (talk) 01:44, 4 April 2011 (UTC)

I notice that the accuracy is reckoned as: "The GAU-8/A accuracy when installed in the A-10 is rated at "5 mil, 80 percent", meaning that 80 percent of rounds fired at 4,000 feet (1,200 m) will hit the target within a 40 feet (12 m) diameter circle."

The link on 'mil' in that section points to http://en.wikipedia.org/wiki/Angular_mil where it says that "...more usefully an angular mil or mil subtends about 1 m at a range of 1,000 m."

If that second reference is correct, as it seems to be, then the former quote is out by an order of magnitude, but I don't know which of the two is the wrong reckoning. 170.9.192.3 (talk) 14:34, 21 November 2012 (UTC)

The quote at Angular mil is for 1 mil and the radius. 5 mils and diameter make a factor of 10. The 4,000 ft (1,200 m) distance & 40 ft (12 m) diameter circle is cited in multiple sources, and matches the trigonometry calculations. -Fnlayson (talk) 18:23, 21 November 2012 (UTC)

The NATO angular mil is 1/6400 of a circle, in practice 1 foot at 1000 feet or 1 meter at 1000 meters. 5 mil would thus be 5 feet at 1000 feet and 5 x 4 = 20 feet at 4000 feet, in other words half of the given figure. The mil figure does not refer to the radius of the hit area but to its diameter.--Death Bredon (talk) 22:13, 25 April 2016 (UTC)

Are you sure about the diameter? Often weapon dispersion is described as a radius of cone, normal distribution, etc. [2] — Preceding unsigned comment added by 109.205.241.251 (talk) 00:58, 27 November 2017 (UTC)

Twice the range, half the time to target, and three times the mass of projectiles carried by comparable close air support aircraft? Their own products falsify that claim.

GAU-8/A Avenger:
30 mm caliber
Muzzle velocity 1,070 m/s (3,500 ft/s)
Projectile weight: 425 grams (15.0 oz).
Close air support use: Lockheed AC-130 Spooky Fairchild Republic A-10 Thunderbolt II "Warthog".

GAU-12 Equalizer:
25 mm caliber
Muzzle velocity: 1,000 m/s (3,280 ft/s)
Projectile weight: 215 grams (7.6 oz)
Close air support use: Fairchild Republic A-10 Thunderbolt II "Warthog" Lockheed AC-130 Spooky.
--Guy Macon (talk) 19:02, 21 November 2012 (UTC)

The aircraft look to be under the wrong cannon/caliber above, unless I am reading the groupings wrong.. -Fnlayson (talk) 19:15, 21 November 2012 (UTC)

Oops! Fixed it. (Note to self: next time, smoke crack after editing Wikipedia...) --Guy Macon (talk) 22:31, 21 November 2012 (UTC)

Actual AP capability

What is the actual AP-capability of this gun? I expect the true values to be classified, but an educated guess would fill my needs.

I'm wondering what the typical target for the A10/Avenger-System is. Can it (successfully) engage a modern MBT? For all light to medium armored Vehicles (APCs, IFVs,...) the results are surely absolutely devastating, but I dont expect it to be able to penetrate the major armor of an MBT. All other major anti tank weapons use around 120mm Tungsten oder DU Pojectiles or high diameter shaped charges, so obviously they are needed. Is the expected way to rip through the lighter top armor? So where ist the limit? Does it penetrate 20cm of RHA? Dispatcher7007 (talk) 14:03, 17 July 2011 (UTC)

Consider that 1) the aircraft has quite a lot of freedom to 'choose' from which direction it attacks. MBT's are poorly protected from the side. 3) It suffices to destroy the tracks in order to take an MBT out of action. 2) other anti tank weapons are "one-shot" weapons, whereas the A10 can probably place around 60 rounds (1 sec salvo) on the tank.Philtime (talk) 17:53, 17 July 2011 (UTC)

Few problems with that- while yes, tanks are less well protected on the sides, its not such a dramatic amount that a 30mm shell will suffice. As for the rapid-fire capability- if one shot doesn't penetrate, another couple dozen won't either. Another problem is that at any physically feasible angle of attack, the apparent armor thickness of even the top of the tank would be greatly magnified- the same principle as sloped armor, but applied in reverse. As far as the tracks, if you look at a picture of most MBTs sides, it'd be pretty hard to hit any exposed track/wheel area from a flying jet aircraft. In short, while any external gear on the tank would get completely wrecked, I doubt there's any way that 30mm cannon could do more than superficial damage to any MBT. Anything less than an MBT, on the other hand, such as trucks, APCs, IFVs, etc, would get chewed up. I think this is simply a case of confusion due to the a-10s role as 'tank killer'. The gun is powerful as all hell, but the tank-killing ability comes from the missiles and bombs the plane carries. 203.110.205.211 (talk) 06:48, 11 February 2012 (UTC)

Let's use actual data instead of making assumptions. By using combat damage assessment we can see that the Gau-8 seems to have no issue penetrating the side of a M47 turret in live fire exercises. While this is an older example of a tank, it is however one that we can actually see the data as to its armor thickness here . The 2.5 inches of cast armor on the side of the turret(and in the case of target tank #39 4 inches of hull armor) is regularly penetrated by the Gau-8 during the assessment. We can also use this armor layout to make assumptions as to the relative thickness of top armor vs. side armor in more modern vehicles. In this case the top of the turret has only 40% of the thickness of the sides of the turret and the top hull armor is roughly 35% of the side of the turret making them far easier to penetrate. While we can only assume that armor has become more effective through the years, expecting a doubling of the protection seems a little far fetched. MBT protection has improved through the use of reactive armor (which is useless against kinetic penetration), increased sloping (dramatically less effective to useless vs non horizontal plane threats), and composite armor (not seen in non western tanks until "probably" the debut of the Armata), not through the increase of heavy RHA and CHA. The sides and rear of MBTs are likely still penetrable by the Gau-8. The top armor of every vehicle is almost certainly vulnerable to the Gau-8.

The above posters pronouncement that the Gau-8 is unlikely to hit suspension components is completely disproved by the results of the live fire as nearly every target tank in the exercise is hit in the tracks, wheels, or sprocket. Fyoutoo (talk) 22:08, 15 December 2015 (UTC)

References

XKCD

This topic was featured on XKCD today: [ http://what-if.xkcd.com/21/ ] --Guy Macon (talk) 22:44, 20 November 2012 (UTC)

Outdated Citation

Citation #15 leads to an error page as of the time of this writing. 76.102.61.178 (talk) 04:16, 8 January 2013 (UTC)

error in "cartridge" size

According to the text, "The shells ... are imposing to examine and handle, measuring 11.4 inches (290 mm) in length ..." but the info box says "Cartridge: 30x173mm" where it should say "Projectile: 30x173mm". The cartridge is the entire round before firing, also known as a shell, which in this case measures 290mm in length. The projectile (or bullet) is the piece in the front that comes out of the gun when fired, in this case 30mm wide by 173mm long. — Preceding unsigned comment added by 69.251.37.117 (talk) 22:49, 5 March 2013 (UTC)

Power source?

One part of the article states that the weapon is powered by two 77hp electric motors (which would be rather large), another states it is powered by the aircraft's two hydraulic systems. The first statement is unsourced; the source for the second states "The aircraft's hydraulic system was used to drive the gun's two motors". Does anyone have a definitive source describing the power train? YSSYguy (talk) 12:13, 8 May 2013 (UTC)

The gun system is electrically controlled, but hydraulically driven. It uses two hydraulic motors running off of the A and/or B side hydraulics. You can find just about anything in the flight manual if you look hard enough. It is not very user friendly, but it is about as authoritative as you are ever gonna get.(1A-10A-1, Pg 1-150,http://www.scribd.com/doc/34087548/To-1A-10A1-A-10A-Flight-Manual)(as of 5/17/13 10:27CST)Fyoutoo (talk) 15:35, 17 May 2013 (UTC)

References

Question, GAU-8 & A-10

should the intro be changed from saying that it is mounted based on the fact that the plane is built around the gun itself? Everettj222 (talk) 22:27, 9 June 2013 (UTC)

The A-10 was not actually "built around" the cannon. The airframe was built separately. It did not rely on the cannon to hold the aircraft together either. Because the GAU-8 was not ready, early A-10s were fitted with a different cannon, M61 I think. -Fnlayson (talk) 22:43, 9 June 2013 (UTC)

GAU is an acronym for "Gatling AUtocannon", "Gun, AUtomatic", or "Gun Aircraft Unit"?

I can't see any explanation in the text for what GAU actually stands for?

Additionally, other sources often refer to it as the AN/GAU, with the "AN" also being unexplained.--Petzl (talk) 23:12, 9 July 2013 (UTC)

Gun Automatic Unit. This is what it is referred to in the 2W151 USAF Aircraft Armament Systems Journeyman career development courses, but those are considered for official use only and I cannot find a user viewable reference. However, I did find a viewable usage of the term in a USAF publication Fyoutoo (talk) 21:24, 26 August 2013 (UTC)

References

AN is "Army and Navy," for multi-service weapons. Bones Jones (talk) 04:24, 24 October 2017 (UTC)

GAU-12/U misinformation under variants

Someone who can be trusted not to break the page should fix this. There is a line under 'Variants" at the bottom of the article that should definitely be fixed or removed. It states...

"Some of the GAU-8/A technology has been transferred into the smaller 25 mm GAU-12/U Equalizer developed for the AV-8B Harrier II aircraft, which is about the same size as the M61, but is considerably more lethal[citation needed]."

Firstly it's tone is rather non encyclopaedic, and secondly it's blatantly and objectively wrong about it's statements regarding size, by a considerable degree. Based even on the wiki page it links to, the GAU-8 Weighs 281kg, and is 6.06 meters long. The GAU-12/U Equalizer Weighs 122kg, and is 2.11 meters long. Additionally the only thing that will make a 25mm cannon "considerably more lethal" than a 30mm cannon capable of the same fire rate, is specialised ammunition, which I very very highly doubt is somehow exclusive to 25mm calibre weapons. I would change it myself, but the citation request was only placed this month, and last time I tried editing a page I cocked something up and uh... a tad paranoid. 92.20.227.185 (talk) 08:32, 22 January 2014 (UTC)

Uh, that comparison is the GAU-12 to the M61. I agree that this needs sourcing, because as written, it's definitely synthesis. - BilCat (talk) 12:31, 22 January 2014 (UTC)

• It is synthesis, but is reasonable given the 20 mm to 25 mm caliber difference. But the comparison is not relevant to the Avenger. I've removed that part. -Fnlayson (talk) 17:01, 22 January 2014 (UTC)

Development of cheap, effective 30mm round

I worked at WPAFB with a neighbor of Colonel Robert Dilger. There is an incredible story here. He was a maverick, he developed the 30 mm round for this gun, on his own and in a most unconventional way. The neighbor reported "loud strange sounds" emanating from Mr. Dilger's property in rural Ohio. Hard to find facts except for the Virginia gas station blowup.Jeb hhoh (talk) 21:09, 5 October 2016 (UTC)

https://books.google.com/books?id=nTtnBA1gbTcC&pg=PA394&lpg=PA394&dq=dilger+GAU-8&source=bl&ots=inFyZIH7Vl&sig=I9TPYFGykMFwnAB9r7bDF0dCoco&hl=en&sa=X&ved=0ahUKEwi7ppzaxcTPAhVKdD4KHT0gCvwQ6AEIPDAI#v=onepage&q=dilger%20GAU-8&f=false