# Recoil on aircraft guns.
**URL:** https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038
**Category:** Factual Questions
**Created:** [January 1, 2003, 2:32pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038 "2003-01-01T14:32:03Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@gouda](https://boards.straightdope.com/u/gouda)
#### Post date: [January 1, 2003, 2:32pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/1 "2003-01-01T14:32:03Z")
I was wondering… guns still exist on fighter aircraft, right??
Doesn’t the recoil of the guns affect the flight of the plane?? With each shot being fired, the aircraft should be thrown _just a little bit_ off course, right? But they don’t, right? How is that compensated for?
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### Author:  [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)
#### Post date: [January 1, 2003, 2:46pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/2 "2003-01-01T14:46:58Z")
Fighter planes are noticeably slowed by the recoil of their forward firing guns. Any variation on pitch or yaw is handled by the pilot making small stick movements. I don’t think planes carry enough ammunition to fire continuously for more than 30 seconds or a minute, so not much correction would be needed.
Something like an AC-130 gunship, with large caliber guns firing out the left side, have a bigger problem, but they are much bigger planes and more resistant to course change. The pilot simply steers a course and makes adjustments.
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### Author:  [@Telemark](https://boards.straightdope.com/u/Telemark)
#### Post date: [January 1, 2003, 4:33pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/3 "2003-01-01T16:33:19Z")
Do a quick web search on the A-10 Warthog (Thunderbolt II). When the pilot fires the 30mm cannon the plane slows down due to the massive amount of depleted uranium being sent forward at a high rate of speed.
> [@](#):
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> At the heart of the A-10 is the awesome GAU-8 Avenger cannon. This 30-mm, seven-barreled rotary cannon fires depleted uranium shells at up to 3,900 rounds per minute
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### Author:  [@Rick](https://boards.straightdope.com/u/Rick)
#### Post date: [January 1, 2003, 4:41pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/4 "2003-01-01T16:41:18Z")
I used to have a neighbor that flew in a B-29 during the war. He told me that one time during a training bomb run he had all the on board guns fire to port as the plane was approaching the drop point. According to him the recoil pushed the plane off course, and caused a clean miss.
Of course this could just be an old soliders tale. I guess some research is needed. Anybody got a B-29, some bombs and a bunch of 50 caliber ammo? 😃
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### Author:  [@Donovan](https://boards.straightdope.com/u/Donovan)
#### Post date: [January 1, 2003, 5:04pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/5 "2003-01-01T17:04:28Z")
I just spent some time looking for the thread from a month or two ago (can’t find it), but someone mentioned that the A-10 (which is essentially an airframe built around an armored cockpit and a bigass gatling gun) has enough recoil from the main gun to cause the plane to stall, and the gun is therefore equipped with an interrupter to keep the plane from stalling. Sorry, no cite, but wouldn’t surpise me if it were true.
(on preview, I see Telemark already mentioned the A10, but if I let that stop me, I’ll never crack 100 posts :))
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### Author:  [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)
#### Post date: [January 1, 2003, 5:23pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/6 "2003-01-01T17:23:27Z")
**Donovan** , you may be thinking of the A-10’s _engines_ stalling from gun gas ingestion. That was a real problem early on, but changes to the engine control system were put in place to close the inlet vanes and turn on the igniters during gun firing. That took care of it. The gun itself doesn’t slow the aircraft enough to stall the wings as long as a minimum airspeed margin is maintained. The recoil does, however, produce a reverse thrust amounting to about 25 percent of the engines’ forward max thrust, and at a 70-per-second pulse rate. That fatigue loading defines the design requirements for some parts, and beats the crap out of the engine bearings, too.
If you look at the nose of an A-10, you’ll see the gun centerline offset from the aircraft centerline, so the active barrel of the 7 is always on the aircraft horizontal centerline. That eliminates yaw from the gun, but not pitch, since it’s still below the aircraft’s center of gravity. Pilots learn to apply some up elevator to compensate for the nose-down pitch the gun produces.
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### Author:  [@UncleBill](https://boards.straightdope.com/u/UncleBill)
#### Post date: [January 1, 2003, 5:27pm UTC](https://boards.straightdope.com/t/recoil-on-aircraft-guns/146038/7 "2003-01-01T17:27:51Z")
[cite of some sort](http://www.canit.se/~griffon/aviation/faq/ramfaq3.txt)
> [@](#):
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> C.19. Is the A-10 actually braked by the gun recoil?
>
> No, not noticably. Pilots report no speed loss even during long bursts. A 70 round burst of 0.4 kg shells fired at 1000 m/s corresponds to a speed reduction of a 15 ton aircraft of 0.2 m/s, which is less than half a knot.
The A-10’s main gun, the GAU-8/A Avenger, is a 30mm, 7 barrel electric Gatlin Gun. It fires very short bursts. From [here](http://members.aol.com/Stravonski/private/gun.html)
> [@](#):
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> The gun gives the A-10 the ability to attack multiple targets in one mission. It is designed to fire its full ammunition load in ten two-second bursts, with one minute to cool down between bursts; in normal use, the bursts and the cool-down time would be much shorter. A one second burst from 4,000ft (1,220m) will put 40 shells into a circle little bigger than the length of a tank, and half-a dozen hits are considered to be a lethal strike. With the theoretical ability to deliver 15-20 such bursts, the A-10 is unlikely to have to abort an attack for want of firepower.