The GAU-22/A thread

Unread postPosted: 30 Dec 2016, 16:55
by steve2267
Searching for GAU-22/A cannon related threads / posts had me pulling my hear out earlier. You can try to search on gun or cannon, but if you want to search for "GAU-22/A", make sure you put double quotes (") around the search string, otherwise it will try to search for gau and 22 and possibly A and you'll end up pulling your hair out too.

I started this thread to try to amalgamate information about the F-35's cannon into one location.

Description
The GAU-22/A is a lighter-weight, four barreled version of the GAU-12/A 25mm cannon used on the AV-8B Harrier. It fires the 25x137mm round which is the same round used in the 25mm chaingun found on the USMC LAV-25 APC and the US Army M2 Bradley. However, the GAU-22/A cannot fire the APFSDS rounds used on the ground vehicles; the separation of the sabot from the sub-caliber munition could cause bad juju for the aircraft (think sabot striking aircraft, getting sucked down intakes etc). The GAU-22/A has a rate of fire of 3300rpm, and a dispersion specification of
5 milliradians diameter, 80 percent circle (1.4 milliradians, 1-sigma radius)
Source: GAU-22/A 25mm Gatling Gun



I'm pretty sure this dispersian specification means that at 3000' range, for example, 80% of the rounds fired will fall within a 40' circle, and the 1-sigma radius means that 67% of the rounds fired will fall within a 4.2' circle.

Manufacturer: General Dynamics Ordnance and Tactical Systems

Here are some PDFs kicking around the interwebs that had to do with the 25mm gun system development on the F-35 program:
Gau-22A_maher.pdf
(2.24 MiB) Downloaded 707 times

TuesdayLandmarkADougHayward.pdf
(4.09 MiB) Downloaded 633 times

TuesdayLandmarkADouglasParker.pdf
(2.32 MiB) Downloaded 578 times


Ammunition
PGU-23 TP (i.e. training round; Orbital ATK)
PGU-25 HEI (high explosive incindiary; Orbital ATK)
PGU-32/U SAPHEI-T (dual purpose high explosive incindiary / anti-armor; Orbital ATK)
PGU-47/U APEX (dual purpose HEI / anti-armor; Nammo - Norwegian Ammunition Company)

References:
25mm_Fact_Sheet.pdf
Orbital ATK
(1.57 MiB) Downloaded 644 times

25-mm-apex-for-the-f35-lightning-ii.pdf
(1.37 MiB) Downloaded 877 times



Orbital ATK specifies the armor penetration of the PGU-32/U to be 13mm RHA @ 30° at 1000m. Nammo quotes 20mm Armour Steel plate @ 45° NATO (?), and 50mm Armour Steel Target plate 0° NATO.

The Ammunition Data Wiki @ Steelbeasts.com lists the PGU-32 SAPHEI armor penetration at 45mm and the 30mm Apache round (30x113mm) M789 HEDP round at 46mm armor penetration. Combined with the Nammo PDF spec of 50mm @ 0° suggests that the F-35 25mm gun's anti-armor capabilities will be on the order of the AH-64 Apache's M230 30mm chaingun. The Nammo round may offer slightly better armor penetration compared to the PGU-32 SAPHEI round. Nammo makes a point that their round is being qualified on all three F-35 variants. I don't know if they mean to imply that the SAPHEI round will not. Perhaps someone can comment.

Re: The GAU-22/A thread

Unread postPosted: 30 Dec 2016, 17:37
by steve2267
With regard to burst length...

Pentagon: F-35 Gun Will Fire in 2017
Brendan McGarry January 8, 2015

“Comprehensive flight test on the F-35A variant GAU-22 25mm gun system is scheduled to begin mid-year at Edwards AFB, Calif., and will include ground fire tests, muzzle calibration, flight test integration and in-flight operational tests,” he wrote.

The GAU-22/A, a four-barrel version of the 25mm GAU-12/U Equalizer five-barrel cannon found on the Marine Corps’ AV-8B Harrier II jump set, is designed to be internally mounted on the Air Force’s F-35A conventional model of the aircraft and hold 182 rounds. It’s slated to be externally mounted on the Marine Corps’ F-35B jump-jet variant and the Navy’s F-35C aircraft carrier version and hold 220 rounds.

That’s a drop in the bucket compared to the 30mm, seven-barrel GAU-8/A Avenger in the nose of the Cold War-era A-10 Warthog attack aircraft, which holds as many as 1,174 rounds.

But it’s actually more than the capacity of other existing front-line fighters, including the Russian MiG-25 and Eurofighter Typhoon, and enough to perform the close air support mission, according to Dave Stouffer, senior manager of business development at General Dynamics’ Ordnance and Tactical Systems unit.

I love the A-10, I’m a former infantry guy,” he said in a telephone interview with Military.com. “No one is going to sit here and say it’s going to be just as good as the A-10.” But, he added, “This 25mm in the Joint Strike Fighter can perform the ground support role … This is a very capable gun system.”

The weapon, one of many slated for the aircraft, is based on a design with a proven track record on both the Harrier and the AC-130 gunship, he said. Linked to the aircraft’s fire control and targeting software, it will fire highly accurate rounds at air-to-ground or air-to-air targets, he said. Also, the exposure point — the time it takes for the pilot to point the plane and its gun at a target — may only last a fraction of a second, translating to nine or 10 bursts of fire, he said.

http://www.dodbuzz.com/2015/01/08/pentagon-f-35-gun-will-fire-in-2017


The Fighter Aircraft Gun Comparison seems to be an interesting comparison of aircraft cannons. It lists the spin-up time of the GAU-22/A cannon at 0.4 seconds, and that it fires 16 rounds in 0.5 seconds. If the GAU-22/A sends 4-5 rounds back to the magazine when it clears itself, then a burst of 16 rounds would consume around 20-21 rounds, which would work out to nine bursts of fire, plus or minus, and would seem to agree with the dodbuzz.com quote above.

(Question: The F-16.net F-16 Armament - M61 A1 Vulcan web page states that the M61 sends between 5-9 unfired rounds back to the ammunition magazine when it clears itself after firing. This ranges from one round less than the number of barrels the M61 hasa to 1.5x the number of barrels. So I am guessing that th GAU-22/A will clear roughly 3-6 rounds when it ceases fire. Can anyone state and/or reference how many rounds are consumed when the GAU-22/A clears itself after firing? (I have not seen any specifications or statements about this.))

Does anyone know if the GAU-22/A gun on the F-35 will be burst-selectable in that the pilot could software select, say, a 10 round, or 15 round, or 20 round burst? I am thinking of a couple different ways to fire this cannon with the ammunition capacity that it has: a semi-auto-burst mode where you could select the number of rounds fired in a burst and only that number are fired with each press of the cannon trigger, or a full-auto mode where the cannon continues to fire as long as you keep the fun switch depressed.

Since so much of the F-35 is software defined, this feature would seem to be a no-brainer, but I have not seen it definitively specified anywhere. So I ask.

Re: The GAU-22/A thread

Unread postPosted: 30 Dec 2016, 22:57
by count_to_10
Wait, does that mean that the F-35 will only be firing 70 to 90% of the ammo actually loaded in it when it "empties" it's gun?

Re: The GAU-22/A thread

Unread postPosted: 30 Dec 2016, 23:18
by wrightwing
steve2267 wrote:With regard to burst length...

Pentagon: F-35 Gun Will Fire in 2017
Brendan McGarry January 8, 2015

“Comprehensive flight test on the F-35A variant GAU-22 25mm gun system is scheduled to begin mid-year at Edwards AFB, Calif., and will include ground fire tests, muzzle calibration, flight test integration and in-flight operational tests,” he wrote.

The GAU-22/A, a four-barrel version of the 25mm GAU-12/U Equalizer five-barrel cannon found on the Marine Corps’ AV-8B Harrier II jump set, is designed to be internally mounted on the Air Force’s F-35A conventional model of the aircraft and hold 182 rounds. It’s slated to be externally mounted on the Marine Corps’ F-35B jump-jet variant and the Navy’s F-35C aircraft carrier version and hold 220 rounds.

That’s a drop in the bucket compared to the 30mm, seven-barrel GAU-8/A Avenger in the nose of the Cold War-era A-10 Warthog attack aircraft, which holds as many as 1,174 rounds.

But it’s actually more than the capacity of other existing front-line fighters, including the Russian MiG-25 and Eurofighter Typhoon, and enough to perform the close air support mission, according to Dave Stouffer, senior manager of business development at General Dynamics’ Ordnance and Tactical Systems unit.

I love the A-10, I’m a former infantry guy,” he said in a telephone interview with Military.com. “No one is going to sit here and say it’s going to be just as good as the A-10.” But, he added, “This 25mm in the Joint Strike Fighter can perform the ground support role … This is a very capable gun system.”

The weapon, one of many slated for the aircraft, is based on a design with a proven track record on both the Harrier and the AC-130 gunship, he said. Linked to the aircraft’s fire control and targeting software, it will fire highly accurate rounds at air-to-ground or air-to-air targets, he said. Also, the exposure point — the time it takes for the pilot to point the plane and its gun at a target — may only last a fraction of a second, translating to nine or 10 bursts of fire, he said.

http://www.dodbuzz.com/2015/01/08/pentagon-f-35-gun-will-fire-in-2017


The Fighter Aircraft Gun Comparison seems to be an interesting comparison of aircraft cannons. It lists the spin-up time of the GAU-22/A cannon at 0.4 seconds, and that it fires 16 rounds in 0.5 seconds. If the GAU-22/A sends 4-5 rounds back to the magazine when it clears itself, then a burst of 16 rounds would consume around 20-21 rounds, which would work out to nine bursts of fire, plus or minus, and would seem to agree with the dodbuzz.com quote above.

(Question: The F-16.net F-16 Armament - M61 A1 Vulcan web page states that the M61 sends between 5-9 unfired rounds back to the ammunition magazine when it clears itself after firing. This ranges from one round less than the number of barrels the M61 hasa to 1.5x the number of barrels. So I am guessing that th GAU-22/A will clear roughly 3-6 rounds when it ceases fire. Can anyone state and/or reference how many rounds are consumed when the GAU-22/A clears itself after firing? (I have not seen any specifications or statements about this.))

Does anyone know if the GAU-22/A gun on the F-35 will be burst-selectable in that the pilot could software select, say, a 10 round, or 15 round, or 20 round burst? I am thinking of a couple different ways to fire this cannon with the ammunition capacity that it has: a semi-auto-burst mode where you could select the number of rounds fired in a burst and only that number are fired with each press of the cannon trigger, or a full-auto mode where the cannon continues to fire as long as you keep the fun switch depressed.

Since so much of the F-35 is software defined, this feature would seem to be a no-brainer, but I have not seen it definitively specified anywhere. So I ask.


Burst lengths can be selected. The only question is just how many options are available, for burst length. Suffice it to say, the pilot won't be emptying the magazine, with a single burst.

Re: The GAU-22/A thread

Unread postPosted: 30 Dec 2016, 23:19
by steve2267
NOTE: This post has been edited. As originally posted, it is incorrect and misleading. The edits reflect the fact that the GAU-22/A is reverse clearing, and undired rounds are returned to the feeding mechanism. No unfired shells are returned to the magazine in normal operation of the cannon.

My original post is quoted below. Edits are in RED. I did it this way to preserve what I originally wrote so future readers could follow the thread, yet correct inaccuracies in what I wrote.

steve2267 wrote:
count_to_10 wrote:Wait, does that mean that the F-35 will only be firing 70 to 90% of the ammo actually loaded in it when it "empties" it's gun?


As I mentioned, the M61 Vulcan reportedly returns 5-9 rounds to the magazine when it clears itself after firing. Unless the GAU-22/A doesn't clear itself after firing, or GDOTS figured a way to return unfired rounds to the feeding mechanism / magazine so they can still be fired, then to answer your question: yes, depending on how many bursts were fired.

[ ETA: They did! They DID! They did figure out a way to return unfired rounds to the feeding mechanism: they clear the GAU-22/A (and GAU-12/U on which the -22 is based) by cycling it in reverse. Everything written below is incorrect for the GAU-22/A. It would have been correct if the gun cleared itself in the same manner as the M61 Vulcan. ]

If you just hold down the fun switch until all rounds have been fired in one, continuous burst, then obviously you will fire 100% of the loaded ammo. If you fire two bursts, and four rounds are returned to the magazine after the first burst, you will have fired 98% of your rounds. Three bursts ~ 8-9 rounds returned for 95% of loaded ammunition expended. Nine bursts of fifteen rounds fired, five rounds returned: 75% loaded ammunition expended, 45 rounds returned. If only four rounds returned when clearing, then a nine bursts yields 16 rounds fired per burst, four returned: 80% loaded rounds will be fired.

Personally, I think the Bk27 might have been a better choice as far as an auto-cannon goes, but that ship sailed a long time ago. If they had used the Bk27, the USMC, among others, loses any possible logistical advantage to using the same calibre round in their ground machines (LAV-25) and the F-35. Granted, they use different rounds, so the logistal advantage may be overstated.

Having said all that, I don't think it is necessarily a bad thing. Yeah, I'd like to be able to use 100% of my loaded rounds, but if the software permits me to fire only 15 rounds at a time, and enables me to accurately target those 15 rounds, that may be all I need.

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 15:18
by count_to_10
Right, I should have said "any plane with a Gatling gun". Of course it isn't specific to the F-35.
It occurs to me, though that, if the ammo belt is one continuous feed that can cycle around multiple times, then you should be able to leave a full burst worth of rounds unexpended after each fired burst. That might be complicated if the pilot wanted to change burst length in flight, but the computer should be able to set things up so that those skipped rounds could be fired in bursts on the second pass through.

Does anyone know if it was possible to fire those skipped rounds (if sporadically and unpredictably) on legacy platforms?

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 15:40
by steve2267
count_to_10 wrote:It occurs to me, though that, if the ammo belt is one continuous feed that can cycle around multiple times, then you should be able to leave a full burst worth of rounds unexpended after each fired burst. That might be complicated if the pilot wanted to change burst length in flight, but the computer should be able to set things up so that those skipped rounds could be fired in bursts on the second pass through.

I will say that may be theoretically possible, but practically impossible. From a computer engineering point of view, yes, the computer should be able to count the shells if you could run them back through the gun again. From a mechanical engineering point of view, this would be a nightmare. Note that you are violating the KISS principle. First, to "find" those unfired shells, you will have to cycle every shell back through the firing mechanism. At 3300rpm, it will take 3.3 seconds to run each round through the firing mechanism. So for a fleeting firing opportunity, you may have to wait upwards of 3 seconds for unfired shells to be re-fed through the gun. I would imagine, in combat, holding the trigger down for 2-3 seconds while keeping the pipper on the target waiting for the gun to spit out a few more shells would be next to eternity. Second, it seems reasonable to assume every shell that has been fired will have expanded slightly from the pressure of the burning propellant gases. If you have ever fired a revolver, you probably have noticed the the "fired" rounds do not slide out of the cylinder as easily as the unfired rounds because they have expanded slightly. You are talking about trying to re-feed fired, empty shells back through the breech. Without a projectile, the unfired cases will just have a sharp, blunt leading edge. If not precisely aligned with the breech, the unfired case will not smoothly enter the breech and will jam the gun. And you are trying to do all this at 55 rounds per second! A redesign of the breech, at a minimum is probably in order.

So while an interesting programming problem, I do not think this is anywhere near practical from a mechanical engineering perspective.
count_to_10 wrote:Does anyone know if it was possible to fire those skipped rounds (if sporadically and unpredictably) on legacy platforms?

While I cannot state authoritatively, I am fairly sure unfired / fired shells could NOT make a second pass through the gun on legacy platforms. (See previous comments about minute shell expansion of fired rounds and problems feeding those back through the gun. If I'm wrong, I will be quite surprised, and would love to read how they solved that engineering problem.)

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 16:04
by cantaz
In some of the videos of the GAU-22 test fires, the gun spins backwards after firing. This might be to clear the unfired rounds back out into the feed chute. The M61 cannot cycle in reverse.

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 16:15
by steve2267
cantaz wrote:In some of the videos of the GAU-22 test fires, the gun spins backwards after firing. This might be to clear the unfired rounds back out into the feed chute. The M61 cannot cycle in reverse.

I never noticed that before - an excellent observation.

In this video you do in fact see the gun spin in the opposite direction briefly (appears to be about one revolution).



count_to_10... it looks like the engineers got your 25-30% back through an elegant solution!

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 16:21
by steve2267
It appears this reverse clearing was a feature of the GAU-12/A as well. Here is a video of the SeaVulcan25. @ 2:45 and 4:05 you can clearly see the barrels reverse briefly after firing.


Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 17:24
by steve2267
Found it! From page 4 of the TuesdayLandmarkADouglasParker.pdf paper attached in post #1 of this thread, the GAU-22/A is reverse clearing.

So everything I posted earlier is INCORRECT for the GAU-22/A. It would have been correct if the GAU-22/A cleared itself in the same manner as the older M61 Vulcan design.

This makes sense and is good to know: all BB's in the F-35's magazine are available to be fired.

Image

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 19:42
by steve2267
Does anyone know (and can share) or has read what gun functionality will be included in the Block 3F software?

Will it be fairly basic like just a boresight pipper and burst round count selector? Or will it also include features like a CCIP (for CAS / ground attack) and LCOS for air-to-air? In air-to-air work, will there be any provision for a TOF/LCOS-only sight based solely on ballistics and aircraft motion in case the radar is offline, damaged, or jammed? If you don't have range information (e.g. radar unavailable), then I'm thinking something like the Viper's gun funnel might be appropriate? On the other hand, if you had DAS sensors near opposite wing tips, you could compute range from the distance between the DAS senors (i.e. binocular vision). Then you wouldn't need the funnel and would just need to deal with a dancing pipper.

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 20:56
by count_to_10
steve2267 wrote:
cantaz wrote:In some of the videos of the GAU-22 test fires, the gun spins backwards after firing. This might be to clear the unfired rounds back out into the feed chute. The M61 cannot cycle in reverse.

I never noticed that before - an excellent observation.

In this video you do in fact see the gun spin in the opposite direction briefly (appears to be about one revolution).



count_to_10... it looks like the engineers got your 25-30% back through an elegant solution!

That would make a lot more sense -- though it would mean loading those "expanded" casing backward through the chamber.
Though I have to say, I can't distinguish a backward motion in that clip from the optical illusion created by the video frame rate.

Re: The GAU-22/A thread

Unread postPosted: 31 Dec 2016, 20:59
by SpudmanWP
Full A/B/C gun usage is included in 3F.

Re: The GAU-22/A thread

Unread postPosted: 16 Feb 2017, 18:32
by steve2267
From the Edwards AFB 461st FTS Deadly Jesters' 2016 F-35 Year in Review video, here are some links to locations in the video with the gun firing:

Aerial gunfire pulling g's: https://youtu.be/PfGuwS2tGPg?t=68

Aerial gunfire - level flight (view from port side): https://youtu.be/PfGuwS2tGPg?t=304

Inverted (negative gee): https://youtu.be/PfGuwS2tGPg?t=392

Gun door closing: https://youtu.be/PfGuwS2tGPg?t=398

Lt Col Grinder Chari begins discussing gunfire testing at 6:47: https://youtu.be/PfGuwS2tGPg?t=407

Sequence of aerial gunfire shots, including level flight, inverted, and high gee / high pitch rate begin at 7:02: https://youtu.be/PfGuwS2tGPg?t=422

High pitch rate at 7:08 https://youtu.be/PfGuwS2tGPg?t=428 -- thermal exhaust plume from the F135 gives an indication of pitch rate being pulled -- it seems to have some pretty good curvature to it.

Re: The GAU-22/A thread

Unread postPosted: 15 Sep 2017, 14:49
by steve2267
Reading between the lines of Dragon's post in the F-35 Updates thread:
Dragon029 wrote:http://www.edwards.af.mil/News/Article/ ... oward-ioc/

As of days ago, all Block 3F F-35A and F-35C WDAs have been completed, with only a single WDA for the F-35B remaining.


If all WDA's have been completed, it would seem that all accuracy / vibration issues with the GAU-22/A have been put to rest. Never did see a press release / announcement to that effect. The lack of any Gilmoresque wining, screaming, or gnashing of teeth would also seem a confirmation of sorts.

Re: The GAU-22/A thread

Unread postPosted: 04 May 2018, 19:28
by steve2267

F-35 Problems: Late IOTE, F-35A Gun Inaccurate, F-35B Tires, Threat Data, Cyber…


by Colin Clark, Jan 26, 2018

...

There’s another important problem which will make it very difficult for the Air Force to argue that it can replace the A-10 with the F-35A, as planned: “The F-35A gun has been consistently missing ground targets during strafe testing; the program is still troubleshooting the problems.” The gun shoots “long, and to the right.” The Marine’s F-35B and the Navy’s F-35C guns, which are not built in, are apparently performing better. “Initial accuracy testing of the F-35B and F-35C podded guns showed better results than that of the F-35A model,” Behler writes. “Both the F-35B and the F-35C gun pods exhibited the same right aiming bias as the F-35A, however the long bias is not manifested in the podded gun systems.”

The other bad news here is that “delays in completing the remaining gun testing and correcting gun-related deficiencies within SDD, especially for the F-35A, are adding risk to the IOT&E schedule,” the report says.

...

https://breakingdefense.com/2018/01/f-35-problems-late-iote-f-35a-gun-inaccurate-f-35b-tires-threat-data-cyber/


Since SDD has been concluded, I am unclear on to what extent, if at all, gun testing and deficiency corrections may have impacted the IOT&E schedule. My impression is that IOT&E is mostly affected by having enough airframes available to perform that testing.

That being said, I recall early "issues" with the gun system involving "vibration." However, I would think that "vibration issues" would tend to either affect firing rate, or decrease accuracy -- open up grouping size(s) -- that is, the gun wouldn't meet the required maximum dispersion specification. The gun consistently "shoot(ing) long, and to the right" sounds like an aiming problem. The pod is consistently shooting right, but not long. Perhaps "long" could be a design / installation issue? If it's consistent... then kentucky windage the thing in the aiming software.

Interesting that the gunpod was performing better than the -A's builtin gun.

Has anyone else seen any thing else gun related?

Re: The GAU-22/A thread

Unread postPosted: 04 May 2018, 19:45
by sprstdlyscottsmn
So, I may be guessing out my butt here... Hitting right sounds like CLAW trying to compensate for the offcenter A model recoil. Hitting long sounds like CLAW trying to compensate for low mounted pod recoil. I do not suspect I am correct by any means, but it sounds like the CLAW uses the same algorithm regardless of model and has too much rudder involved. I honestly expect to be wrong because that would be a rookie mistake.

Re: The GAU-22/A thread

Unread postPosted: 04 May 2018, 19:55
by steve2267
Spurts, sounds good to me, though the article noted the -A was long too... and the gun is above the a/c CG on the -A, isn't it?

Still, it sounds to me like something that is software fixable. If they were saying the gun was all over the place (e.g. shooting 10 mil dispersion diameter rather than the spec 5 mil diameter), then I'd say there were more serious issues a foot.

The F-35 is the first jet whereby man has aimed the cannon through a helmet mounted sight. i wonder if there could be some parallax kind of issues or just other HMS issues involved? Still... how much different is it projecting a dot or pipper out in space on an HMS vs a HUD?

The article is four months old, it's about the DOT&E report, so how much older might that information be? For all I know, all gun issues have been put to rest, but I've read no stories from the stellar aviation / aerospace press core about the resolution of any F-35 gun system issues. (They love to tell you when it's broke... not so much when the problem is fixed.) Given the lack of media harumphing over a broken gun, I'm guessing it is a non-issue and has been resolved... but...

Re: The GAU-22/A thread

Unread postPosted: 04 May 2018, 20:22
by wrightwing
SDD is complete, and no further issues have been mentioned with the guns.

Re: The GAU-22/A thread

Unread postPosted: 04 May 2018, 21:54
by steve2267
From FY2017 DOD Programs - F-35 Joint Strike Fighter (JSF), to which Spud had previously linked back on 1-24-18:

* Flight testing of the different gun systems on the F-35 (internal gun for F-35A and external gun pods for the F-35B and F-35C) revealed problems with effectiveness, accuracy, pilot controls, and gunsights displayed in the Helmet Mounted Display System (HMDS). The synopsis and assessment of specific HMDS problems are classified. The gun profiles include the testing and qualification of four separate 25 mm rounds in the two gun types. The F-35A internal gun testing includes the PGU-23 training round, PGU-47 Armor Piercing High Explosive Incendiary round, and the PGU-48 Frangible Armor Piercing round. The F-35B and the F-35C variants external gun pod testing is limited to the PGU-32 Semi-Armor Piercing High Explosive Incendiary round used by the Marine Corps.

p.42 of http://www.dote.osd.mil/pub/reports/FY2 ... f35jsf.pdf


Gun Testing
  • Gun Activity
    • All three F-35 variants add gun capability with Block 3F. The F-35A gun is internal; the F-35B and F-35C each use an external gun pod. Differences in the outer mold-line fairing mounting make the gun pods unique to a specific variant (i.e., an F-35B gun pod cannot be mounted on an F-35C aircraft).
    • AF-31, the only Block 3F mission systems-capable F-35A test aircraft configured for gun testing, completed the first air-to-ground gun firing at Naval Air Weapons Station (NAWS) China Lake, California, in February 2017.
      • Helmet Mounted Display System (HMDS) alignment problems identified during the test event prevented further weapons demonstration activities with the gun until corrections were developed and tested. The test team accomplished a risk reduction test flight in March while awaiting resolution of the HMDS alignment and line-of-sight problems.
      • AF-31 completed an air-to-ground live fire accuracy event on September 27, 2017, and a gun lethality mission on October 5. Additional testing was ongoing at the time of this report.
    • BF-1 completed the first F-35B airborne gun firing on February 21, 2017. BF-1 then attempted more gun testing in March, but gun pod problems, weather, and range availability prevented the completion of the initial set of scheduled events.
      • BF-1 resumed testing in April, but gun pod seal problems and cracks at the FS 346.5 frame further delayed testing. BF-1 completed airborne gun firing in May to complete the flight sciences testing of the gun pod on the F-35B.
      • BF-17, the only Block 3F mission systems-capable test aircraft configured for gun accuracy testing, completed a gun lethality mission on September 12, 2017.
    • CF-3 performed the first F-35C airborne gun firing on June 6, 2017, and continued more gun testing throughout the month. It completed flight sciences testing with the gun pod in July.
  • Gun Assessment
    • F-35A gun accuracy testing on AF-31 demonstrated uncharacterized bias toward long and right of the target. Also, the gunsight display in the HMDS was cluttered and slow to stabilize.
    • The initial F-35B strafing results with the gun pod have been better than those for the F-35A. The aim-point projection through the HMDS was more stable and the F-35B does not appear to have significant angular bias errors like the F-35A. The program will complete accuracy assessments; however, because the program used just a single aircraft per variant to assess compliance with specification requirements, the JPO will make more assessments with OT aircraft before and during IOT&E.
    • F-35C accuracy results with the gun pod to date have been consistent with those observed with the F-35B.
    • The JOTT and the Services will need to develop shot-kill criteria, possibly for each variant, to assess the effectiveness of simulated gun employment during training and test mission trials in IOT&E. Ongoing delays in completing the remaining gun testing and correcting gun-related deficiencies within SDD, especially for the F-35A, are adding risk to the IOT&E schedule.

p.43 of http://www.dote.osd.mil/pub/reports/FY2 ... f35jsf.pdf


So to summarize:
  • sounds like gun system assessment to continue during IOT&E as there was only one -A, one -B, and one -C available for gun testing during SDD.
  • -A had (has?) some HMDS display issues
  • -A also has "significant angular bias errors" (someone needs to brush up on their trig? :oops: )
  • The services still need to settle on what constitutes a gun kill

I find it significant that there was no mention of "vibration" issues that were made a (semi-)big deal of a year ago.

Sounds like normal development issues that are still being worked through -- I don't see any big oopses or major issues.

Re: The GAU-22/A thread

Unread postPosted: 05 May 2018, 20:51
by archeman
I never understood why the USAF didn't pony up the development cost to mod the external gun pod for the A model.

In one pretty simple move, the USAF could have silenced the 'Big Guns Win Wars' crowd and given the A-10 chest beaters something serious to chew on (dual GAU-22s) which would nearly double the A-10 rate of fire and nearly match the total A-10 kilojules of kinetic target impact.
A lesser but not unimportant note of course is that doubling the cannon fire of the F-35A it actually WOULD be a serious ground attack improvement. It wouldn't become twice as effective overall but when it did transition into ground strafe it would saturate the target area exactly 100% better than before.

Re: The GAU-22/A thread

Unread postPosted: 05 May 2018, 21:58
by magitsu
archeman wrote:I never understood why the USAF didn't pony up the development cost to mod the external gun pod for the A model.

In one pretty simple move, the USAF could have silenced the 'Big Guns Win Wars' crowd and given the A-10 chest beaters something serious to chew on (dual GAU-22s) which would nearly double the A-10 rate of fire and nearly match the total A-10 kilojules of kinetic target impact.
A lesser but not unimportant note of course is that doubling the cannon fire of the F-35A it actually WOULD be a serious ground attack improvement. It wouldn't become twice as effective overall but when it did transition into ground strafe it would saturate the target area exactly 100% better than before.

Why would anyone in their right mind start ground strafing with F-35? If such a cozy airspace exists in the future, the likes of Tucano can handle it. Cannon isn't really that effective, almost a sideshow compared to PGMs with jets. There are certain platforms like AC-130 for it though.

Re: The GAU-22/A thread

Unread postPosted: 05 May 2018, 22:22
by archeman
magitsu wrote:
archeman wrote:I never understood why the USAF didn't pony up the development cost to mod the external gun pod for the A model.

.......

Why would anyone in their right mind start ground strafing with F-35? If such a cozy airspace exists in the future, the likes of Tucano can handle it. Cannon isn't really that effective, almost a sideshow compared to PGMs with jets. There are certain platforms like AC-130 for it though.


Apparently EVERYONE that purchased the F-35A is considering it's ground strafe capability.
They train pilots for ground strafe.
They design ammunition for ground strafe.
The have continued to work software and ground targeting issues related to ground strafe.

It is just another method and tool in the arsenal of democracy apparently. If you're going to have weapons at all, they should work well, and you should know how to use them.

Re: The GAU-22/A thread

Unread postPosted: 05 May 2018, 22:30
by zhangmdev
magitsu wrote:Why would anyone in their right mind start ground strafing with F-35? <snip>


There are videos of F-16 doing strafing run in anger as recent as 2013?

Strafing is still a part of Air Force pilot training

http://www.f-16.net/f-16-news-article2947.html

Re: The GAU-22/A thread

Unread postPosted: 05 May 2018, 23:27
by wrightwing
archeman wrote:I never understood why the USAF didn't pony up the development cost to mod the external gun pod for the A model.

In one pretty simple move, the USAF could have silenced the 'Big Guns Win Wars' crowd and given the A-10 chest beaters something serious to chew on (dual GAU-22s) which would nearly double the A-10 rate of fire and nearly match the total A-10 kilojules of kinetic target impact.
A lesser but not unimportant note of course is that doubling the cannon fire of the F-35A it actually WOULD be a serious ground attack improvement. It wouldn't become twice as effective overall but when it did transition into ground strafe it would saturate the target area exactly 100% better than before.

Because PGMs and not guns, are the primary and preferred A2G weapons (including the A-10.l

Re: The GAU-22/A thread

Unread postPosted: 06 May 2018, 00:45
by count_to_10
Is the A’s gun door causing the problem?

Re: The GAU-22/A thread

Unread postPosted: 06 May 2018, 01:42
by steve2267
count_to_10 wrote:Is the A’s gun door causing the problem?


I've read nothing that states, let alone even suggests that. What are you thinking / why would you ask that?

As I ponder your question, though... I do wonder... could local flow perturbation caused by the door possibly cause the inaccuracy? Man, I have to think LM accounted for that -- that someone would have thought of it or otherwise considered it and accounted for such an effect.

But in the favor of a "gun door causing a problem" line of inquiry, the door always opens to the same position, so any effect (e.g. right bias) would be the same, and repeatable. On the other hand, flow perturbation effects (e.g. strength) could possibly change with airspeed, and at some critical Mach number, maybe 0.7M or 0.8M, I wonder if a local shock could be established by the door fairing. But would a projectile exiting the muzzle at > 1000m/s be sufficiently perturbed by such a local flow burble?

Still... it sounds like the gun bias is consistent. If it can be quantified and mapped vs flight dynamics variables, then it should be fixable via software kentucky windage.

Re: The GAU-22/A thread

Unread postPosted: 06 May 2018, 10:06
by magitsu
archeman wrote:It is just another method and tool in the arsenal of democracy apparently. If you're going to have weapons at all, they should work well, and you should know how to use them.

There's a long way between use what you have and should've built a "GAU-8 Avenger -type" cannon pod.

Everybody and their mother has MANPADS these days, which makes sub 5k ft flight asking for trouble. So anything more than a backup cannon is a waste. Laser pod might make more sense, but probably not specifically for CAS as other uses might reach maturity earlier.

Re: The GAU-22/A thread

Unread postPosted: 06 May 2018, 12:06
by gtg947h
steve2267 wrote:
count_to_10 wrote:Is the A’s gun door causing the problem?


I've read nothing that states, let alone even suggests that. What are you thinking / why would you ask that?

As I ponder your question, though... I do wonder... could local flow perturbation caused by the door possibly cause the inaccuracy? Man, I have to think LM accounted for that -- that someone would have thought of it or otherwise considered it and accounted for such an effect.

But in the favor of a "gun door causing a problem" line of inquiry, the door always opens to the same position, so any effect (e.g. right bias) would be the same, and repeatable. On the other hand, flow perturbation effects (e.g. strength) could possibly change with airspeed, and at some critical Mach number, maybe 0.7M or 0.8M, I wonder if a local shock could be established by the door fairing. But would a projectile exiting the muzzle at > 1000m/s be sufficiently perturbed by such a local flow burble?

Still... it sounds like the gun bias is consistent. If it can be quantified and mapped vs flight dynamics variables, then it should be fixable via software kentucky windage.


This is why you do testing. Even with computers, sometimes you encounter things you never expected and find out things behave differently than you thought. Aerodynamic computation is still based off empirical models that need to be tweaked, refined, and validated with wind tunnel and flight testing. Structural fatigue involves a lot of statistics based off lots of empirical testing, from the coupon level up to whole airframe. And even then, once your airplane is in service you start finding cracks and issues elsewhere.

So as you said--"normal development issues".

Re: The GAU-22/A thread

Unread postPosted: 08 May 2018, 15:01
by stevedapirate
archeman wrote:I never understood why the USAF didn't pony up the development cost to mod the external gun pod for the A model.

In one pretty simple move, the USAF could have silenced the 'Big Guns Win Wars' crowd and given the A-10 chest beaters something serious to chew on (dual GAU-22s) which would nearly double the A-10 rate of fire and nearly match the total A-10 kilojules of kinetic target impact.


I'm also curious about why the USAF didn't pony up for the gun pod, but in order to omit the internal cannon altogether. It would provide more commonality with the B and C variants of the jet and free up additional internal weight and volume that could be used for fuel.

I wonder how much weight that would actually free up. The gun itself is ~230lbs, but you've also got ammunition and storage/handling equipment, electric motor, structural reinforcements and changes to handle vibration and recoil, and the mechanism for the gun door.

Would deleting the internal gun in favor of additional fuel be the equivalent of giving the F-35A a little 330 gal drop tank?

Re: The GAU-22/A thread

Unread postPosted: 08 May 2018, 16:11
by steve2267
stevedapirate wrote:
Would deleting the internal gun in favor of additional fuel be the equivalent of giving the F-35A a little 330 gal drop tank?


The GAU-22/A internal installation in the -A model is fairly compact. Without running any numbers, I'd still hazard a guess that volume is still far less than what 330gal of JP-8 would occupy.

Do not forget that the -B is rated to 7g, and the -C to 7.5g. You either have to de-rate the -A to 7.5g for a pod, or design the pod to handle 9g. All the associated hardware will have to cope with an increased load rating, and probably increased vibration environment as well.

Re: The GAU-22/A thread

Unread postPosted: 08 May 2018, 17:40
by stevedapirate
steve2267 wrote:Do not forget that the -B is rated to 7g, and the -C to 7.5g. You either have to de-rate the -A to 7.5g for a pod, or design the pod to handle 9g.


Designing the gun pod to withstand an extra 1.5g (assuming it isn't already) doesn't seem like a huge hurdle as most of the complexity and moving parts are in the gun itself and ammunition handling systems, which we know are already rated to 9g since they are currently installed in the F-35A.

I think you'd just be evaluating the pod enclosure, attachment bolts, and maybe the latch to an access door on the pod.

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 03:21
by spazsinbad
PHOTOS: 388th FW fires F-35A cannon for first time
15 Aug 2018 Todd Cromar, 388th Fighter Wing Public Affairs

"Pilots from the 388th Fighter Wing’s 4th Fighter Squadron were the first operational unit to fire the F-35A’s 25 mm cannon in a strafing run during training. The two-ship formation fired on two sets of ground targets on the Utah Test and Training range Aug. 13. Loading and firing the cannon was one of the few capabilities Airmen in the 388th and 419th FWs had yet to demonstrate. The F-35A’s internal cannon allows the aircraft to maintain stealth against air adversaries as well as fire more accurately on ground targets, giving pilots more tactical flexibility. (Air Force photo by Todd Cromar)"
https://media.defense.gov/2018/Aug/15/2 ... 5-0009.JPG (1.1Mb)

Source: https://www.acc.af.mil/News/Article-Dis ... irst-time/

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 04:00
by popcorn
Presumably the target they were aiming at is obscured by the dust/smoke. :mrgreen:

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 04:51
by steve2267
No mention if the pilot got to hose off an Aim-9X prior to the strafing practice...

Image

Image

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 15:03
by mk82
Brrrttttttt.....on time....on target!!

The F35A can now use its internal gun operationally (and accurately too). Wait!! I hear the heads of F35 naysayers imploding again!! Lol!

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 15:47
by steve2267
In his article, https://theaviationist.com/2018/08/16/t ... -training/, Cenciotti states that Aim-9X was inert. Dumb question, why fly around with an inert 9X? The test boys have already conducted all the asymmetric and 9X firing tests. Only guess I have is if the F-35 avionics only do certain 9X-specific "tricks" if they know there is one on the wing?

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 16:11
by spazsinbad
:doh: :devil: INERT 'WINDER UNDER PORT WING DRAG STOPS THE GUN FIRING HIGH & TO THE RIGHT DONCHA KNOW! :devil: :doh:

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 16:40
by steve2267
spazsinbad wrote::doh: :devil: INERT 'WINDER UNDER PORT WING DRAG STOPS THE GUN FIRING HIGH & TO THE RIGHT DONCHA KNOW! :devil: :doh:


LMAO... good one Spaz... and here I was thinking a few lines of C++ code and maybe a table lookup woulda Kentuckee windaged the bullyetts back into place...

Re: The GAU-22/A thread

Unread postPosted: 17 Aug 2018, 16:52
by quicksilver
steve2267 wrote:In his article, https://theaviationist.com/2018/08/16/t ... -training/, Cenciotti states that Aim-9X was inert. Dumb question, why fly around with an inert 9X? The test boys have already conducted all the asymmetric and 9X firing tests. Only guess I have is if the F-35 avionics only do certain 9X-specific "tricks" if they know there is one on the wing?


Zzzzzzz...

Captive carry of AIM-9 has been going on for decades. You want the seeker-head feed to the weapons system for training.

Re: The GAU-22/A thread

Unread postPosted: 18 Aug 2018, 11:49
by forbin
Many pics in this configuration with 2 AIM-9X can be considered stealth as it ?
The gun had a problem internal not or less in pod fired too on the side fixed now ?

Re: The GAU-22/A thread

Unread postPosted: 18 Aug 2018, 14:33
by steve2267
forbin wrote:Many pics in this configuration with 2 AIM-9X can be considered stealth as it ?


If you are asking whether the F-35 retains its VLO characteristics when carrying two AIM-9X, I think the general consensus around here is that external AIM-9X carriage degrades VLO by some amount, but by how much, no one knows, and those that know aren't saying. Some have said the F-35 is "still stealthy", or "must still be stealthy or else XYX..." but no one knows for sure, and no numbers have been thrown around, let alone quoted.

forbin wrote:The gun had a problem internal not or less in pod fired too on the side fixed now ?


Is English your native language? I don't ask this to be rude, but I do not understand this question at all.

Re: The GAU-22/A thread

Unread postPosted: 18 Aug 2018, 14:51
by quicksilver
steve the swashbuckler said:

"I'm also curious about why the USAF didn't pony up for the gun pod, but in order to omit the internal cannon altogether. It would provide more commonality with the B and C variants of the jet and free up additional internal weight and volume that could be used for fuel."

F-35A (a much smaller aircraft than Raptor) carries more internal fuel. Fuel/range wasn’t really going to be an issue, so why give up a capability for which there is both strong rationale and strong emotions? Fairly easy trades on that for the A.

Re: The GAU-22/A thread

Unread postPosted: 18 Aug 2018, 17:39
by zerion
steve2267 wrote:
forbin wrote:The gun had a problem internal not or less in pod fired too on the side fixed now ?


Is English your native language? I don't ask this to be rude, but I do not understand this question at all.


He’s wondering if the drift problem caused by the door of the internal gun was fixed.

Re: The GAU-22/A thread

Unread postPosted: 18 Aug 2018, 17:52
by spazsinbad
:doh: Yep - with swinder drag (see above). :devil: See my previous post previous page this thread. :drool:

Re: The GAU-22/A thread

Unread postPosted: 20 Aug 2018, 15:58
by forbin
zerion wrote:
steve2267 wrote:
forbin wrote:The gun had a problem internal not or less in pod fired too on the side fixed now ?


Is English your native language? I don't ask this to be rude, but I do not understand this question at all.


He’s wondering if the drift problem caused by the door of the internal gun was fixed.

Yes :D and according i know about 0.5 sec for open the door so a no stealth fighter have a little advantage

steve2267 wrote:
forbin wrote:Many pics in this configuration with 2 AIM-9X can be considered stealth as it ?


If you are asking whether the F-35 retains its VLO characteristics when carrying two AIM-9X, I think the general consensus around here is that external AIM-9X carriage degrades VLO by some amount, but by how much, no one knows, and those that know aren't saying. Some have said the F-35 is "still stealthy", or "must still be stealthy or else XYX..." but no one knows for sure, and no numbers have been thrown around, let alone quoted.

forbin wrote:The gun had a problem internal not or less in pod fired too on the side fixed now ?


Is English your native language? I don't ask this to be rude, but I do not understand this question at all.

No problem and Ofc no and sorry sometimes limited :(

For this with number i consider a steath with RCS especialy frontal inferior to m2 above Typhoon, Rafale etc... are low observable better than 4th generation but remains much more detectable than stealth.

So without ext weapons F-35 have a frontal RCS 0,00143 m2 or - 30 dBsm i think rear -20 ?

And my question is with 2 small AIM-9X which have a wingspan of 28 - 30 cm vs 45 for AIM-120C/D in more stealth HP with
it F-35* especialy A is again stealth inferior to m2 ? i ask coz many pics where i see it and possible exist a reason.

Thanks :)

* Seems too for B/C with in more the gun in pod.

Re: The GAU-22/A thread

Unread postPosted: 24 Aug 2018, 21:21
by spazsinbad

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 02:30
by madrat
Love the 'brrrrt' sound. Sounds eerily similar to GAU-8.

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 02:41
by beepa
Is it just the video or does that door stay open after the run??

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 05:50
by mk82
Sacre bleu A10!!! The F35 “brrrrrrrts” pretty well too LOL! :devil:

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 06:45
by charlielima223
People are still bitching about the magazine capacity for the F-35A. Its really annoying. :bang:

maybe if they get their heads out of their 4th point of contact and understand that the gun on the F-35 wont be its primary means of engaging ground targets, then they wouldn't be so damn annoying. Hell... even the GAU-8 (as awesome as it is) isn't the primary means of engagement for the A-10 in most situations.
Of course I would always come across this uneducated comment
The A-10 used the its 30mm cannon to kill tanks in Iraq

No, the GAU-8 wasn't the primary or the most successful/effective means of destroying Iraqi tanks in the Gulf War, it was bombs and the AGM-65.
Also when compared to the magazine size of other aircraft (Western European and Russian), the F-35 still has a larger magazine capacity, but that doesn't matter because its not the GAU-8 :bang:

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 06:55
by mk82
charlielima223 wrote:People are still bitching about the magazine capacity for the F-35A. Its really annoying. :bang:

maybe if they get their heads out of their 4th point of contact and understand that the gun on the F-35 wont be its primary means of engaging ground targets, then they wouldn't be so damn annoying. Hell... even the GAU-8 (as awesome as it is) isn't the primary means of engagement for the A-10 in most situations.
Of course I would always come across this uneducated comment
The A-10 used the its 30mm cannon to kill tanks in Iraq

No, the GAU-8 wasn't the primary or the most successful/effective means of destroying Iraqi tanks in the Gulf War, it was bombs and the AGM-65.
Also when compared to the magazine size of other aircraft (Western European and Russian), the F-35 still has a larger magazine capacity, but that doesn't matter because its not the GAU-8 :bang:


Donccha know.......in the land of the basement dwellers.....the GAU 8 slays all! And saves the rainforest too LOL!

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 15:16
by ricnunes
mk82 wrote:Donccha know.......in the land of the basement dwellers.....the GAU 8 slays all! And saves the rainforest too LOL!


And stops global climate/warming changes too :mrgreen:

Guess what? The reason for all these global climate changes is because the USAF wants to retire the A-10s and the GAU-8s by association :wink:

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 16:44
by steve2267
The video above is quite remarkable. At about the 0:02 or 0:03 mark the brrrrrt is quite short, so short in fact, that I suspect we immediately hear an echo of the brrrrrt. Could this be an example of a short, programmed burst of 20 or 30 rounds? I do not think any other American aircraft armed with a gatling gun can fire so short a burst. If true, this means the Panther can piss off upwards of 6-9 brrrrrrts per sortie. In his book, Viper Pilot, Hampton was winchester after only three strafe passes. The Vulcan squirts the shells out right quick. So from a number of strafe runs per sorties, the F-35 does not appear to be any worse, practically, from the F-16 (511 rds), F/A-18 (578 rds), or F/A-18E/F Super Duper (412 rds).

One metric used to discuss / analyze / design gun systems for tactical aircraft is throw weight. In one second, an M61 Vulcan set at the 6000rpm rate, will fire 100 shells each weighing approx. 102g, or 10.2 kg in a second. Contrast that with the GAU-22/A spitting out fifty 25x137mm Nammo PGU-47/U Apex 223g(*) projectiles a second for a total one second throw weight of 11.1 kg /sec. So a full rate burst from the GAU-22/A has a better throw weight compared to the teen series aircraft. (Only the Harrier and the Hawg, of US aircraft, will have higher per second throw weights.)

Comparing the F-35A to the F-16 for total throw weights, the F-35A will have about 40.6 kg of shells, where the F-16 has 52.1kg total shell throw weight.

In addition, as has been mentioned before, the GA-22/A, like the GAU-12/A has a backward clearing system -- when the gun has completed firing a burst, any unfired shells are returned to the ammunition feeding system, so no live shells are "wasted."

With a greater kinetic effect per shell, a high per second throw weight, and the efficient use of ammunition (e.g. short, precise bursts), I would say the trades performed in creating the F-35 gun system have resulted in an extremely effective weapons system.

Lastly, it would be nice if the journo wannabees had the wherewithall to ask questions such as:
  1. The F-35 has been described as a flying supercomputer. With all that computing power, has George been designed to fly or otherwise fine tune the flight path such that, with a commit switch (or authorize to release) depressed, George will position the aircraft and automatically fire the gun to deposit 25mm shells on the target indicated by the pilot's helmet gunsight?
  2. Could such a feature apply both to Air to Ground strafing missions as well as to Air to Air combat? After all, the fourth gen aircraft have had CCRP / CCIP forever now... why not let George greatly increase the Pk of a gun engagement?
  3. Can the APG-81 track the outbound cannon shells and be used to either create a closed system gun solution (ala the Phalanx), or update in real time the helmet display gun pipper?

(*) p. 8 from https://ndiastorage.blob.core.usgovclou ... 9Sande.pdf

Re: The GAU-22/A thread

Unread postPosted: 25 Aug 2018, 19:26
by knowan
steve2267 wrote:One metric used to discuss / analyze / design gun systems for tactical aircraft is throw weight. In one second, an M61 Vulcan set at the 6000rpm rate, will fire 100 shells each weighing approx. 102g, or 10.2 kg in a second. Contrast that with the GAU-22/A spitting out fifty 25x137mm Nammo PGU-47/U Apex 223g(*) projectiles a second for a total one second throw weight of 11.1 kg /sec. So a full rate burst from the GAU-22/A has a better throw weight compared to the teen series aircraft. (Only the Harrier and the Hawg, of US aircraft, will have higher per second throw weights.)

Comparing the F-35A to the F-16 for total throw weights, the F-35A will have about 40.6 kg of shells, where the F-16 has 52.1kg total shell throw weight.


Here's data for F-35 and some other planes.

F-35, 25mm GAU-22/A with 180 rounds.
3300 RPM / 55 RPS rate of fire, 223 gram projectile weight for 12.3 kg/s throw weight, 3.27 seconds firing time of ammunition and 40.1 kg of total projectile weight.

F-18E/F, 20mm M61A1 with 412 rounds.
6000 RPM / 100 RPS rate of fire, 102 gram projectile weight for 10.2 kg/s throw weight, 4.12 seconds firing time of ammunition and 42.0 kg total projectile weight.

Typhoon, 27mm BK 27 with 150 rounds.
1800 RPM / 30 RPS rate of fire, 260 gram projectile weight for 7.8 kg/s throw weight, 5.00 seconds firing time of ammunition and 39.0 kg total projectile weight.

Gripen, 27mm BK 27 with 120 rounds.
1800 RPM / 30 RPS rate of fire, 260 gram projectile weight for 7.8 kg/s throw weight, 4.00 seconds firing time of ammunition and 31.2 kg total projectile weight.

Rafale, 30mm GIAT 30 with 125 rounds.
2500 RPM / 42 RPS rate of fire, 275 gram projectile weight for 11.6 kg/s throw weight, 2.98 seconds firing time of ammunition and 34.4 kg total projectile weight.

Su-35, 30mm GSh-30-1 with 150 rounds.
1800 RPM / 30 RPS rate of fire, 390 gram projectile weight for 11.7 kg/s throw weight, 5.00 seconds firing time of ammunition and 58.5 kg total projectile weight.

Re: The GAU-22/A thread

Unread postPosted: 26 Aug 2018, 04:08
by kimjongnumbaun
charlielima223 wrote:People are still bitching about the magazine capacity for the F-35A. Its really annoying. :bang:

maybe if they get their heads out of their 4th point of contact and understand that the gun on the F-35 wont be its primary means of engaging ground targets, then they wouldn't be so damn annoying. Hell... even the GAU-8 (as awesome as it is) isn't the primary means of engagement for the A-10 in most situations.
Of course I would always come across this uneducated comment
The A-10 used the its 30mm cannon to kill tanks in Iraq

No, the GAU-8 wasn't the primary or the most successful/effective means of destroying Iraqi tanks in the Gulf War, it was bombs and the AGM-65.
Also when compared to the magazine size of other aircraft (Western European and Russian), the F-35 still has a larger magazine capacity, but that doesn't matter because its not the GAU-8 :bang:


Indeed, the GAU-8 didn't even have the ability to penetrate most tanks from the front.

https://imgur.com/gallery/fd4sK

Re: The GAU-22/A thread

Unread postPosted: 26 Aug 2018, 11:29
by forbin
kimjongnumbaun wrote:
charlielima223 wrote:People are still bitching about the magazine capacity for the F-35A. Its really annoying. :bang:

maybe if they get their heads out of their 4th point of contact and understand that the gun on the F-35 wont be its primary means of engaging ground targets, then they wouldn't be so damn annoying. Hell... even the GAU-8 (as awesome as it is) isn't the primary means of engagement for the A-10 in most situations.
Of course I would always come across this uneducated comment
The A-10 used the its 30mm cannon to kill tanks in Iraq

No, the GAU-8 wasn't the primary or the most successful/effective means of destroying Iraqi tanks in the Gulf War, it was bombs and the AGM-65.
Also when compared to the magazine size of other aircraft (Western European and Russian), the F-35 still has a larger magazine capacity, but that doesn't matter because its not the GAU-8 :bang:


Indeed, the GAU-8 didn't even have the ability to penetrate most tanks from the front.

https://imgur.com/gallery/fd4sK


Normal it is a 30 mm gun for comparison HS-129 a flying tank ! had same caliber and attacked always on the side or rear last variants had a 75 mm !

Re: The GAU-22/A thread

Unread postPosted: 26 Aug 2018, 12:19
by hythelday
kimjongnumbaun wrote:
charlielima223 wrote:People are still bitching about the magazine capacity for the F-35A. Its really annoying. :bang:

maybe if they get their heads out of their 4th point of contact and understand that the gun on the F-35 wont be its primary means of engaging ground targets, then they wouldn't be so damn annoying. Hell... even the GAU-8 (as awesome as it is) isn't the primary means of engagement for the A-10 in most situations.
Of course I would always come across this uneducated comment
The A-10 used the its 30mm cannon to kill tanks in Iraq

No, the GAU-8 wasn't the primary or the most successful/effective means of destroying Iraqi tanks in the Gulf War, it was bombs and the AGM-65.
Also when compared to the magazine size of other aircraft (Western European and Russian), the F-35 still has a larger magazine capacity, but that doesn't matter because its not the GAU-8 :bang:


Indeed, the GAU-8 didn't even have the ability to penetrate most tanks from the front.

https://imgur.com/gallery/fd4sK


This argument is usually brought up to counter "muh GAU-8 brrrrt!" crowd, but it is not that solid, IMO:

1) An MBT with shredded barrel, tracks, roadwheels, sights and ERA is still an operational loss for the enemy. E.g. T-72's engine bay is virtually unarmored from the top. (a couple of Serbian M-84s strafed by A-10: http://www.srpskioklop.paluba.info/grob ... L-GT16.HTM and http://www.srpskioklop.paluba.info/grob ... -gt17.html)

2) BMP-1 & -2s wouldn't have stood a chance

It's just that A-10 as a platform for GAU-8 is not as survivable as was anticipated. A-10As flew over Iraqi divisions only after their AD were worked on by DEAD aircraft, and still suffered 250% more losses (to IR and visually guided Shilkas) per sortie than F-16s; not hard to imagine what would have happened against WarPac and their a tad more advanced (Iraq didn't have Tunguska, Tor or Buk in any quantity) and better trained AD assets in a conflict that wouldn't have the luxury of preliminary "softening up".

Re: The GAU-22/A thread

Unread postPosted: 27 Aug 2018, 05:10
by charlielima223
hythelday wrote:
This argument is usually brought up to counter "muh GAU-8 brrrrt!" crowd, but it is not that solid, IMO:

1) An MBT with shredded barrel, tracks, roadwheels, sights and ERA is still an operational loss for the enemy. E.g. T-72's engine bay is virtually unarmored from the top. (a couple of Serbian M-84s strafed by A-10: http://www.srpskioklop.paluba.info/grob ... L-GT16.HTM and http://www.srpskioklop.paluba.info/grob ... -gt17.html)

2) BMP-1 & -2s wouldn't have stood a chance



True, I will give you that. However, majority of people talk about the GAU-8 they always talk about its "effectiveness" against heavily armored targets like tanks. From my understanding of this document, the effectiveness of the GAU-8 to effectively destroy an MBT is heavily dictated on where on the tank the A-10 is engaging from (L side, R side, Front, and back) and at what angle

http://www.dtic.mil/dtic/tr/fulltext/u2/a522397.pdf

I will give it to the GAU-8 that against older model tanks, the GAU-8 can be considered effective. Yet against more modern designs, it is (IMO) highly questionable.

Re: The GAU-22/A thread

Unread postPosted: 27 Aug 2018, 05:46
by viper12
Also, the report shows the typical engagement with the GAU-8 was around 2,500ft away in a 4-degree dive typically, so not exactly a standoff range and which would mean an altitude of around 175ft AGL.

The average open-fire speed is given as 568ft/s, so if one were to assume the A-10 flew horizontally at that speed at 175ft AGL, and the enemy AA can open fire at anything above 4° of elevation, that's an 8.78-second window of opportunity to shoot at the A-10, which pretty much means you'd need an automated system with fast reaction times to engage it.

As a food for thought, you can check some numbers about the reaction time of the ZSU-23-4 against choppers : https://www.globalsecurity.org/military ... 84/CSJ.htm

In this example, the target was missed during the first
burst of fire. A second long burst destroyed the target.
The length of time required to complete the operation
previously described will depend on gunner proficiency and
training, but a Soviet article in 1979 stated that in a
timed test of ZSU's engaging targets without radar "the
majority of the crews were lost, much time was wasted
finding targets, refining and using the fire data. The
result of this is that gun crews opened fire, as a rule,
minutes after the helicopters appeared."12 The best
trained crew and most experienced in the test took 32
seconds.

Re: The GAU-22/A thread

Unread postPosted: 27 Aug 2018, 06:02
by charlielima223
viper12 wrote: that's an 8.78-second window of opportunity to shoot at the A-10, which pretty much means you'd need an automated system with fast reaction times to engage it.


For modern SHORAD platforms/systems, that is a pretty big window. Look how quickly this phalanx can engage


Re: The GAU-22/A thread

Unread postPosted: 27 Aug 2018, 09:21
by hornetfinn
Systems like 2S6 Tunguska, German Gepard, Marksman (used in Finland) and some other self propelled anti-aircraft systems can pretty easily fire within 5-10 seconds after detecting a target. All can also fire at anything as far as there is direct LOS between target and AD system. All have max effective firing range between 3,000-4,000 m (10,000 to 13,000 ft) with guns. 2S6 Tunguska could even engage further out with missiles. A-10 would be in a world of trouble against all of them. Of course the only potential system it could've ever met of these is 2S6 Tunguska (or later Pantsir-variants) which became operational in early 1980s. Of course it took to 1990 before it became more widespread in Soviet/Russian army. ZSU-23-4 was very limited system with poor performance but was widely used because it was cheap and fairly simple and reliable system.

Re: The GAU-22/A thread

Unread postPosted: 27 Aug 2018, 14:27
by hythelday
hornetfinn wrote:ZSU-23-4 was very limited system with poor performance but was widely used because it was cheap and fairly simple and reliable system.


Still, Shilka and Osa were enough to punish low-fliers, including F-15Es, A-7s (before they were ordered higher). The worst loss per sortie in that war belongs to Tornados, who had to attack airfields with JP233 at low altitude on the first days of war.

Re: The GAU-22/A thread

Unread postPosted: 30 Aug 2018, 14:42
by ricnunes
hythelday wrote:It's just that A-10 as a platform for GAU-8 is not as survivable as was anticipated.


Precisely.
Actually this can be "easily experienced" by anyone:
1- Purchase DCS A-10C combat flight simulator for PC. This is the most realistic A-10 (it models the -C variant of the A-10) ever made for PC (basically it is for the A-10 what Falcon BMS is for this F-16). Actually this simulator (DCS A-10C) is used by the Air National Guard (ANG) as a training tool.
2- Play the campaign which comes with the simulator. The campaign is set on a (present day/near future) fictional conventional-warfare scenario which pits NATO against Russian Forces on Georgia.
3- Try attacking ground targets with the GAU-8 and see how long you'll survive :roll:
Just as a note, Russian forces in this campaign are equipped with a myriad of assets, including air defenses such as the SA-15.

Just as a note, I ended this campaign two years ago and if my memory doesn't fail me I only fired the gun (GAU-8) during that campaign only once and this was against an enemy helicopter which was harassing friendly forces and this after running out of Sidewinder missiles.

Basically in this scenario/campaign set what I did was the following:
- Flying at 15,000 ft (and it wasn't higher because the A-10C fully loaded could hardly reach higher altitudes) and using predominantly the GBU-12 (and sometimes I also used the CBU-105). Against static targets such as Bridges, I used the GBU-31 JDAM. Does this reminds you of something?? :wink:
Only rarely did I use the AGM-65 Maverick on that campaign.

Basically while playing the campaign above I ended myself and often swearing the following:
" My kingdom for an F-16!"
(now imagine a F-35??)

I know that this is a computer game but an excellent one IMO (to the point that it's also used as a training tool by ANG) and clearly proves on a "first person" perspective how vulnerable the A-10 is against modern air defense systems, moreover so if it uses the gun.

Re: The GAU-22/A thread

Unread postPosted: 30 Aug 2018, 15:03
by sferrin
hornetfinn wrote:Systems like 2S6 Tunguska, German Gepard, Marksman (used in Finland) and some other self propelled anti-aircraft systems can pretty easily fire within 5-10 seconds after detecting a target. All can also fire at anything as far as there is direct LOS between target and AD system. All have max effective firing range between 3,000-4,000 m (10,000 to 13,000 ft) with guns. 2S6 Tunguska could even engage further out with missiles. A-10 would be in a world of trouble against all of them. Of course the only potential system it could've ever met of these is 2S6 Tunguska (or later Pantsir-variants) which became operational in early 1980s. Of course it took to 1990 before it became more widespread in Soviet/Russian army. ZSU-23-4 was very limited system with poor performance but was widely used because it was cheap and fairly simple and reliable system.


TOR would happily eat A-10s for breakfast as well.

Re: The GAU-22/A thread

Unread postPosted: 30 Aug 2018, 17:17
by sprstdlyscottsmn
ricnunes wrote:I know that this is a computer game

That is a disservice to DCS: A-10C. It is a fully immersive aircraft study in which every system and subsystem is modeled for maximum accuracy. As you know, you can't start the campaign without first going through nearly a dozen training missions so that you know how to operate the systems on the A-10. Many of them you need to go through more than once to be comfortable with the operation. For anyone who has played, it is easy to see how that program and the HOTAS Warthog flight sticks could allow real pilots to maintain their systems operating skills when at home.

And yes, trying to use the gun with anything bigger than a 7.62mm around has a 50% chance or ending with you being killed or mission killed (mission critical subsystem destroyed)

Re: The GAU-22/A thread

Unread postPosted: 30 Aug 2018, 20:19
by ricnunes
sprstdlyscottsmn wrote:
ricnunes wrote:I know that this is a computer game

That is a disservice to DCS: A-10C. It is a fully immersive aircraft study in which every system and subsystem is modeled for maximum accuracy.


I didn't mean to do a disservice to DCS: A-10C, by the contrary since and as you can clearly see, I used it as an evidence that the A-10 and its gun is "irrelevant" or more precisely too risky for use in current and future conventional wars. I would never have used a "mere computer game" as a such.

However, I admit that I should have put quotes around the "computer game" words.

Re: The GAU-22/A thread

Unread postPosted: 30 Aug 2018, 20:47
by basher54321
AFAIK originally the version did for the ANG was A-10C Suite 3.1 pre 2010 and part of the contract for a public version included removing and simplifying certain systems as you can see in the TOs. So the module itself is a simulator but the systems only go as far as what was allowed (unsurprisingly).

Only comment on the AI defence units would be very simplistic at best.

Re: The GAU-22/A thread

Unread postPosted: 31 Aug 2018, 09:54
by hornetfinn
hythelday wrote:
hornetfinn wrote:ZSU-23-4 was very limited system with poor performance but was widely used because it was cheap and fairly simple and reliable system.


Still, Shilka and Osa were enough to punish low-fliers, including F-15Es, A-7s (before they were ordered higher). The worst loss per sortie in that war belongs to Tornados, who had to attack airfields with JP233 at low altitude on the first days of war.


Very true. Flying low is extremely dangerous if there are any working AD systems around. Modern systems are far more lethal than Shilkas or Osas. Some of them would be difficult to destroy or degrade with SEAD/DEAD as they use passive sensors and/or advanced radar systems with extremely quick reaction times and short time-of-flight missiles. Modern SPAAG systems generally use 30-40mm guns (some even bigger) which would break even A-10 into half trouble. Getting inside their kill zones would be very dangerous and IMO just stupid if there are better ways of doing things.

Re: The GAU-22/A thread

Unread postPosted: 31 Aug 2018, 12:44
by ricnunes
basher54321 wrote:AFAIK originally the version did for the ANG was A-10C Suite 3.1 pre 2010 and part of the contract for a public version included removing and simplifying certain systems as you can see in the TOs. So the module itself is a simulator but the systems only go as far as what was allowed (unsurprisingly).


Yes, of course. If I'm not mistaken one of the things that was "removed from the public version" was the MAWS (Missile Approach Warning System) which the public version also models albeit in a simplified way.

But and despite this, this is still the most realistic A-10 simulator ever release to the general public and the modeled systems are still very close to their real counterparts (as close as they can be) and as such I really believe that its a good "tool" to learn more about the A-10C, how it is to be an A-10C pilot and how pilots fight with it and together with its conventional-warfare campaign it gives a very, very good idea (again, IMO) about what we're discussing here (the vulnerabilities of the A-10 against an enemy equipped with good air defense systems).

Re: The GAU-22/A thread

Unread postPosted: 31 Aug 2018, 15:01
by sprstdlyscottsmn
Also, as I understand it, GAU-8 dispersion. It is more of a shotgun than the real thing.

Re: The GAU-22/A thread

Unread postPosted: 14 Sep 2018, 00:29
by steve2267
Nammo completes first live fire trials of GAU-22 gun for F-35 aircraft
13 September 2018

Norwegian / Finnish aerospace and defence group Nordic Ammunition Company (Nammo) has concluded the maiden live fire trials of the GAU-22 Gatling gun.

Developed specifically for the F-35 Lightning II, the four-barrelled GAU-22 gun was fired at Nammo’s purpose-built facility in Raufoss, Norway.

The gun is currently the only weapon of its kind being used outside the US.

Nammo Aircraft Ammunition programme director Anders Nyhus said: “This setup is really unique, in that allows us to do all the testing we need just minutes away from the production site.

But it's good, IMHO, that Nammo is proceeding with APEX production, which appears to be a highly effective munition ranging from anti-armor usage (light armor) through to air-to-air uses.

“That again means that can cut down the time between a production lot leaving the factory, and when it is tested and ready to go to the customer. It also means we can have a much higher confidence in the quality of the products we deliver, as we are able to control every aspect of the process from beginning to end.”

The GAU-22 Gatling gun and its associated facility have been procured through an agreement with the Norwegian Defense Materiel Agency as part of the development of Nammo’s APEX-ammunition for the F-35.

The APEX is the only ammunition type that is available for the F-35 fighter jets and will enable the aircraft to use its gun effectively in any scenario.

Nammo serves as the only ammunition provider for the F-35 aircraft able to carry out a complete range of verification and acceptance testing for every production lot independently.

https://www.airforce-technology.com/news/nammo-live-fire-trials-gau-22-f-35/


I didn't realize APEX "is the only ammunition type that is available for the F-35," I thought Orbital ATK, now swallowed up by Northrop Grumman, was also producing ammunition for the GAU-22/A.

Re: The GAU-22/A thread

Unread postPosted: 14 Sep 2018, 01:20
by Dragon029
That might potentially be just for Norway or international partners; the US has different ammunition cleared for the F-35.

Re: The GAU-22/A thread

Unread postPosted: 14 Sep 2018, 02:44
by steve2267
Dragon029 wrote:That might potentially be just for Norway or international partners; the US has different ammunition cleared for the F-35.


That is my understanding. Just another very poorly written article by a I-wannabee-a-journalist, IMO. It would have been very easy to make that clarification. I am not aware of airforce-technology.com being a Norwegian-centric, nor even a Euro-centric site. But I may be wrong.

My biggest takeaway from the article, which I probably should have mentioned when I quoted the article, is that NAMMO apparently has their very own GAU-22/A with which they can perform immediate testing of production lots of 25mm ammunition.

Re: The GAU-22/A thread

Unread postPosted: 14 Sep 2018, 10:03
by marsavian
steve2267 wrote:
forbin wrote:Many pics in this configuration with 2 AIM-9X can be considered stealth as it ?


If you are asking whether the F-35 retains its VLO characteristics when carrying two AIM-9X, I think the general consensus around here is that external AIM-9X carriage degrades VLO by some amount, but by how much, no one knows, and those that know aren't saying. Some have said the F-35 is "still stealthy", or "must still be stealthy or else XYX..." but no one knows for sure, and no numbers have been thrown around, let alone quoted.

forbin wrote:The gun had a problem internal not or less in pod fired too on the side fixed now ?


Is English your native language? I don't ask this to be rude, but I do not understand this question at all.


The frontal RCS probably goes up to the 0.001-0.01 sq m range which is still better than the Su-57 and probably in the J-20 zone. The point is they went to the trouble of purposely designing small canted low RCS pylons so it would not be high. So it's still stealthy to everything else and that's even before jamming is used if ever detected. Discussed further here ...

viewtopic.php?f=22&t=27356

Re: The GAU-22/A thread

Unread postPosted: 24 Sep 2018, 17:49
by steve2267
Looks like the flying Leathernecks like their guns... took them on their float aboard the Essex to the ME:

U.S. Marine Corps F-35B Jets Involved In First Operational Deployment Near the Horn of Africa Flying With External Gun Pod
by David Cenciotti Sep 21 2018

Photos show Marines F-35B aircraft carrying the external gun pod during exercise off the coast of Djibouti.

For the last two weeks, U.S. Marine Corps F-35Bs assigned to the Marine Fighter Attack Squadron (VMFA) 211 “Wake Island Avengers”, deployed with the 13th Marine Expeditionary Unit, have undertaken the type’s first operational deployment in international waters off the coast of Djibouti.

Beginning on Sept. 8, the aircraft have taken part in a Theater Amphiobious Combat Rehearsal (TACR) operating from the flight deck of Wasp-class amphibious assault ship USS Essex (LHD 2), deployed to the U.S. Central Command area of responsibility near Horn of Africa along with the rest of the Essex Amphibious Ready Group, that includes the San Antonio-class amphibious transport dock USS Anchorage (LPD 23) and Whidbey Island-class amphibious dock landing ship USS Rushmore (LSD 47).

The F-35B were involved in CAS (Close Air Support) missions, supporting Marines on the ground during drills in the military ranges in Djibouti that, according to USNI News, involved Marine Medium Tiltrotor Squadron 166 (Reinforced)’s complement of CH-53E Super Stallion heavy-lift helicopters, MV-22 Osprey tilt-rotor aircraft, UH-1 Huey utility helicopters and AH-1 Cobra attack helicopters

... [more blah blah blah at the jump]

https://theaviationist.com/2018/09/21/u-s-marine-corps-f-35b-jets-involved-in-first-operational-deployment-near-the-horn-of-africa-flying-with-external-gun-pod/


A couple of notes...
  • Appears to be positive incidence on the tail slabs, so the tails appear to be generating lift
  • Why are the gunpods painted white? I would think you'd want a grey to match the aircraft?
  • Looks like they got some shootin' in -- second photo appears to show discoloration consistent with cannon firing

Image

Image

Re: The GAU-22/A thread

Unread postPosted: 24 Sep 2018, 18:50
by element1loop
There's some blue-biasing and brightness in the pretty images that's washing-out the grey color of the pod. It's since been marketed as a multi-mission pod. Just a mock-up but you get the idea, multiple role options.

Image

https://www.terma.com/press/news-2012/f ... n-display/

Re: The GAU-22/A thread

Unread postPosted: 24 Sep 2018, 19:22
by marsavian
https://theaviationist.com/2018/09/21/u ... l-gun-pod/

The new General Dynamics GAU-22 25mm gun pod uses a unique four-barrel configuration that was developed from the highly successful five-barrel, 25mm GAU-12/U gun also built by General Dynamics. Noteworthy, although it was designed with LO (Low Observability) characteristics, the external pod degrades the F-35’s radar cross section making the 5th generation aircraft more visibile to radars. Still, this should be acceptable (as it is for the non-stealthy AV-8B Harrier jets they will replace) for the scenarios where the U.S. Marine Corps F-35Bs will be called to carry out CAS missions (read here about the so-called “third day of war” configuration).


Image

Re: The GAU-22/A thread

Unread postPosted: 24 Sep 2018, 21:51
by spazsinbad
The first fotie has the Bee formating on photie taker so the control surfaces could be everywhichwaybutloose temporarily. I'm guessing incorrect film/digital camera setting/maybe iFone? for 'high in the air' BRIGHT SUNLIGHT photos or rongfilter was used to mess up the colour space but whatever. Second photo is perhaps more towards a correct colour but BRIGHT.

Also the photo is taken thru the filter of the tanker window covering which does not help - amateurish stuff really. :mrgreen:

Re: The GAU-22/A thread

Unread postPosted: 25 Sep 2018, 00:15
by steve2267
spazsinbad wrote:The first fotie has the Bee formating on photie taker so the control surfaces could be everywhichwaybutloose temporarily.


Formation flying not withstanding... at this lower airspeed, am guessing that the flaperons may be used more for roll control than the slabs? But I considered both photographs, and they both seemed to suggest positive incidence for the stabs. Just more "evidence" (?) of the unstable static characteristics of the design and that by having all aero surface generating lift, drag is minimized. FWIW.

Re: The GAU-22/A thread

Unread postPosted: 25 Sep 2018, 01:18
by spazsinbad
F-35B GUN TEST Complete @ NAS Patuxent River May 2017 https://www.youtube.com/watch?v=_msXQAXNbvU


Re: The GAU-22/A thread

Unread postPosted: 25 Sep 2018, 01:59
by steve2267
The gunpods in that video and still frame posted by spaz sure seem to be much closer to the color of the F-35B than the ones I posted from the aviationist up above.

Re: The GAU-22/A thread

Unread postPosted: 25 Sep 2018, 02:15
by spazsinbad
Not sure why this is important however I don't reckon the GUN POD is white in colour, meanwhile another WALLOP set up:

https://lexleader.net/wp-content/upload ... 10x420.jpg from:

https://lexleader.net/runway-project-mo ... or-summer/
&
THEN A C BABY:
"F-35C flies for the first time with 10 weapons plus gun pod. 4x external GBU-12, 2x internal GBU-32, 2x internal AMRAAM, 2x external Sidewinder 9X." http://www.codeonemagazine.com/images/m ... 7_5170.jpg

Then another B Bubba:
"PATUXENT RIVER, Md. – On June 14, F-35B Joint Strike Fighter test aircraft BF-2 completed the first test flight for the short takeoff and vertical landing variant with an asymmetric weapons load. Cmdr. Eric Buus flew BF-2 with an AIM-9X Sidewinder inert missile on the starboard pylon, a centerline 25 mm gun pod, and a GBU-32 and AIM-120 in the starboard weapon bay...." https://www.flickr.com/photos/marine_corps/7419480466 for https://farm6.staticflickr.com/5275/741 ... 32_o_d.jpg (3.3Mb)

Re: The GAU-22/A thread

Unread postPosted: 16 Nov 2018, 02:00
by steve2267
Found this cutaway photograph illustrating the Nammo APEX PGU-47/U 25mm round on Twitter:

PGU-47  Nammo Apex round cutaway.jpg


Here is an illustration of the APEX projectile from p.7 of https://ndiastorage.blob.core.usgovclou ... 9Sande.pdf

25mm PGU-47U APEX Projectile Design.PNG

Re: The GAU-22/A thread

Unread postPosted: 16 Nov 2018, 02:18
by steve2267
At 6 sec and 26 sec of this video of the F-35's strafing practice this past August in Utah, the bursts are incredibly short. It would be interesting to know how few rounds were expended in these bursts and if this is an example of the "round counting" or "round setting" ability in the F-35 gun system. (But that would mean defense aerospace journalists actually figuring out and asking some interesting questions.)


Re: The GAU-22/A thread

Unread postPosted: 16 Nov 2018, 03:04
by spazsinbad
Per Request 4 Page Extract attached from NAMMO for AMMO: https://www.nammo.com/globalassets/pdfs ... screen.pdf (5.2Mb) APEX LIVE FIRE TESTING AND EVALUATION BullyTin 2017 EVA K. FRIIS, APEX PROGRAM DIRECTOR, EXPLAINS THE SIGNIFICANT PROGRESS MADE BY THE 25 MM APEX AMMUNITION, AND WHAT LIES AHEAD FOR 2017

Re: The GAU-22/A thread

Unread postPosted: 16 Nov 2018, 12:18
by Dragon029
steve2267 wrote:At 6 sec and 26 sec of this video of the F-35's strafing practice this past August in Utah, the bursts are incredibly short. It would be interesting to know how few rounds were expended in these bursts and if this is an example of the "round counting" or "round setting" ability in the F-35 gun system. (But that would mean defense aerospace journalists actually figuring out and asking some interesting questions.)


12 rounds based on the audio:

Image

Re: The GAU-22/A thread

Unread postPosted: 16 Nov 2018, 14:38
by steve2267
This Nammo APEX ammunition impresses me the more I learn of it. I know the US has developed their own rounds via ATK (now part of Northrop Grumman), but I wish the US had simply contracted with Nammo.

From the article found here https://www.defence24.com/dezamet-suppo ... 5-analysis, the following image I presume to be of 25mm APEX penetration test against an angled piece of armor. While previously posted PDFs from Nammo presentations better illustrate the armor penetration capabilities of the PGU-47/U from a technical perspective, this image is very telling, I think (lots of hot fragments):

Nammo_25mm_APEX_45deg_penetration_test.png


While I am not saying the GAU-22/A is a tank killer, this depiction of modern MBT armor thicknesses suggests that ALL MBT's have weaknesses somewhere (20-30mm RHA) that an aircraft should be able to exploit, short of the tank being dug in an all sides under a concrete parking structure or shelter. (Still, for an MBT, Spear or SDB II would be a much better choice.)

Leopard-2A4-LOSy.jpg
Image found here: http://btvt.narod.ru/raznoe/leopard2/Leopard-2A4-LOSy.jpg

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 05:23
by wrightwing
steve2267 wrote:At 6 sec and 26 sec of this video of the F-35's strafing practice this past August in Utah, the bursts are incredibly short. It would be interesting to know how few rounds were expended in these bursts and if this is an example of the "round counting" or "round setting" ability in the F-35 gun system. (But that would mean defense aerospace journalists actually figuring out and asking some interesting questions.)


The burst length is selectable. The pilot isn't "free gunning."

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 05:35
by steve2267
wrightwing wrote:The burst length is selectable. The pilot isn't "free gunning."


Oh, I understand this fact. But this is the first "hard" evidence I have seen of this capability -- a capability I do not believe any other tactical aircraft shares, short of possibly an AC-130 gunship.

But I am curious if the pilot can type in or specify the number of rounds in a burst, or if he has to select a preset burst length.

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 05:49
by wrightwing
steve2267 wrote:[



Oh, I understand this fact. But this is the first "hard" evidence I have seen of this capability -- a capability I do not believe any other tactical aircraft shares, short of possibly an AC-130 gunship.

But I am curious if the pilot can type in or specify the number of rounds in a burst, or if he has to select a preset burst length.

The end result would be similar, however the system works. I know from previous tests, there were specific round counts, so my guess is that it's round selectable. I'm not sure what the low end round count is, but if it's 10 to 12rds, that's 15 to 18 short bursts.

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 05:52
by spazsinbad
'wrightwing' do you have an URL source for this info please? "The burst length is selectable. The pilot isn't "free gunning."" THANKS.

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 05:59
by steve2267
A recent news quote about the Auto-GCAS capability refers to a "combat autopilot." If this leads to the capability of the pilot designating a target with a deathdot in his HMDS, and then letting George fly the aircraft within some pilot designated time-frame to automagically put a 15 round burst on that target... that would be some capability.

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 16:09
by mixelflick
First all new gun since the Vulcan used in everything from the Phantom to Raptor, correct?

The bigger round is a step up and should do the job strafing most targets. It'll never be the GAU-8 but hey, what is? Hopefully it can punch a hole in a tank, or at least keep their heads down for a bit.

Of more interest to me is its air to air "punch". For decades we seem to have favored the lighter M61 20mm cannon for use in our fighters. The Russians and Europeans, heavier 23 and 30mm rounds (though carrying fewer of them than the M61). So what's the thinking here? Need more "umph" to cause more damage to bigger and more powerful (Flanker) airframes? Or is the move to 25mm solely to find a sweet spot for air to ground/air to air engagements?

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 18:20
by zerion
Video of Dutch 323TES Squadron loading gun and gun run.

https://twitter.com/Kon_Luchtmacht/stat ... 5706190849

he seemed to like it.

(P.S. anyone know how to pull just a video off Twitter?)

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 18:42
by steve2267
Edited to add:
I cannot cite references or sources stating the reason why a caliber larger than the 102x20mm was chosen. However, one of the first 3 PDF's I attached to the original post of this thread stated that the gun system was primarily intended for air-to-ground use. Either in that same document, or something I read in the past day or so, stated that the gun was estimated to be used about 70-80% of the time in an A2G role, and only 20-30% in an air-to-air role.

mixelflick wrote:First all new gun since the Vulcan used in everything from the Phantom to Raptor, correct?


The AV-8B is (optionally) equipped with a 5-barrel GAU-12/A Avenger gun system, from which General Dynamics derived the GAU-22/A used on the F-35. Various AC-130 gunships have also used the GAU-12/A.

mixelflick wrote:The bigger round is a step up and should do the job strafing most targets. It'll never be the GAU-8 but hey, what is? Hopefully it can punch a hole in a tank, or at least keep their heads down for a bit.


The GAU-8/A on the A-10 kills tanks by defeating the tank's armor where it is thinner (think top, sides, and rear). I do not have memorized the armor penetration values for the 30x173mm round the A-10 carries. The Nammo APEX PGU-47/A round will penetrate 50mm rolled homogenous armor (RHA) at 0° incidence. Taking into account a realistic incidence angle (30-45° ?) suggests there are places on modern MBTs that may be vulnerable to an F-35 strafing it: typically the top / back part of the turret, and/or the top / back part of the rear deck where the engine is typically located. That being said, I don't think anyone considers the GAU-22/A to be a primary tank-killing weapon of the F-35. That would be a SDB-II, SPEAR, or possibly a GBU-49.

The US appears to be standardizing on either a FAP or PELE round by ATK. IMO, the APEX is superior as it is usable across the full spectrum of targets from soft to hard, whereas FAP/PELE seems more appropriate to harder targets as they do not utilize any explosives.

mixelflick wrote:Of more interest to me is its air to air "punch". For decades we seem to have favored the lighter M61 20mm cannon for use in our fighters. The Russians and Europeans, heavier 23 and 30mm rounds (though carrying fewer of them than the M61). So what's the thinking here? Need more "umph" to cause more damage to bigger and more powerful (Flanker) airframes? Or is the move to 25mm solely to find a sweet spot for air to ground/air to air engagements?


If you perused any of the PDF's I included in the first post of this thread, you will see that the gun system is (was) not intended to be a primary air-to-air weapon. It's intended, primary use is to service ground targets.

With that said, air-to-air gunnery is a tradeoff between accuracy, dispersion, shell velocity, shell lethality and firing rate. You want the gun to be accurate, yet you want a "dispersion" pattern at your optimum firing range to maximize the chances that a shell will detonate on the target (think shotgun pattern size at expected target distance). A former Phantom driver told me you ideally wanted 50 kts overtake or closure speed, and optimum firing distance was 1000-1500ft. He said you did not want to engage closer than 500ft (if saddled up) because the risk was high that you would fly through a debris field, to the detriment of your own jet's health. Also, 2000-2500 ft would be a really long shot. High velocity minimizes time of flight (TOF) of the projectiles, removing as much guesswork as possible from estimating where the target will be after 1 TOF (since both attacking aircraft and target are moving in 3D at (typically) high rates, afterall.) Firing rate relates to shot density (think number of pellets in a shotgun blast.) In fact, the shotgun analogy is apropos here. Do you choose a 12 gauge 00 shell with 9 pellets or a #7 shot shell for birds with lots and lots of tiny pellets? Percentage chance that you hit the target increases with the number of pellets, but the damage inflicted decreases with the smaller pellet size. What works for a duck probably won't work on a bear. For air-to-air gunnery, the US has historically favored higher firing rate and accepted smaller projectile size & mass with the 102x20mm round and the M61 Vulcan as the air-to-air cannon of choice since its choice on the F-104. Since WWII, the Europeans and Russians have favored 27mm or 30mm for their fighter aircraft cannon.

If you multiply firing rate by shell mass, you obtain throw weight which is a common metric used to compare aircraft gun systems. A succinct summary comparing the various aircraft cannons can be found in this post on ar15.com:

F-35A, 25mm GAU-22/A with 180 rounds.
3300 RPM / 55 RPS rate of fire, 223 gram projectile weight for 12.3 kg/s throw weight, 3.27 seconds firing time of ammunition and 40.1 kg of total projectile weight.

F/A-18E/F, 20mm M61A1 with 412 rounds.
6000 RPM / 100 RPS rate of fire, 102 gram projectile weight for 10.2 kg/s throw weight, 4.12 seconds firing time of ammunition and 42.0 kg total projectile weight.

Typhoon, 27mm BK 27 with 150 rounds.
1800 RPM / 30 RPS rate of fire, 260 gram projectile weight for 7.8 kg/s throw weight, 5.00 seconds firing time of ammunition and 39.0 kg total projectile weight.

Gripen, 27mm BK 27 with 120 rounds.
1800 RPM / 30 RPS rate of fire, 260 gram projectile weight for 7.8 kg/s throw weight, 4.00 seconds firing time of ammunition and 31.2 kg total projectile weight.

Rafale, 30mm GIAT 30 with 125 rounds.
2500 RPM / 42 RPS rate of fire, 275 gram projectile weight for 11.6 kg/s throw weight, 2.98 seconds firing time of ammunition and 34.4 kg total projectile weight.

Su-35, 30mm GSh-30-1 with 150 rounds.
1800 RPM / 30 RPS rate of fire, 390 gram projectile weight for 11.7 kg/s throw weight, 5.00 seconds firing time of ammunition and 58.5 kg total projectile weight.

The biggest difference with the F-35A and GAU-22/A is that it has more programmable bursts. For A2A, you could get 9 x 20rd bursts if you wanted, or 3 x 60rd bursts, etc.

One of the assumptions most outside observers have made is that the F-35 will rely on missiles for its first kills in A2A, when the gun is more of an option in the F-35 than any 4th Gen jet as a first kill system when approaching VLO. Threat air is flying along, all of a sudden they get shredded by 25mm dual-purpose projectiles and don't know why.

https://www.ar15.com/forums/general/F-3 ... #i74212670


IMO, the GAU-22/A represents a masterful compromise, especially if the Nammo PGU-47/U APEX round is used, of
  • high rate of fire (though not as high as the Vulcan, but probably more than "dense enough for air-to-air work)
  • very good throw weight (in fact, highest of all cannon listed above)
  • decent total throw weight
  • high velocity (~1000m/sec)
  • very good shell lethality against both soft and hard targets (PGU-47/U APEX)
  • very good gun accuracy / low dispersion (nascent F-35 aiming issues aside)
  • high round / burst efficiency with the ability to select very short bursts (e.g. 12-15 rounds each)

That is, the GAU-22/A appears to be a really good gun system, quite possibly the best in any modern fighter, 4th or 5th generation. It will certainly shred trucks and kill APC's and light armor. It appears it may be effective against armor if attacked from the correct direction.

If combined with a combat autopilot function (think AutoGCAS for a gun solution), it may be a truly killer air-to-air solution especially combined with efficient, short round count bursts.

I hope I have addressed your questions.

Re: The GAU-22/A thread

Unread postPosted: 17 Nov 2018, 19:20
by spazsinbad
zerion wrote:Video of Dutch 323TES Squadron loading gun and gun run.
https://twitter.com/Kon_Luchtmacht/stat ... 5706190849
he seemed to like it. (P.S. anyone know how to pull just a video off Twitter?)

Yep. Doing it now (see GIF) WinX YouTube Downloader is FREE. It will truncate the video file name but works well.

https://www.winxdvd.com/download.htm SCROLL DOWN THE PAGE:
https://www.winxdvd.com/download/winx-y ... loader.exe FREE DOWNLOAD 27.6Mb

Luchtmacht - Wederom een mijlpaal voor het 323TES .mp4 (10.5Mb) attached for you.

Re: The GAU-22/A thread

Unread postPosted: 18 Nov 2018, 02:03
by zerion
Thanks

Re: The GAU-22/A thread

Unread postPosted: 18 Nov 2018, 03:35
by marauder2048
. Taking into account a realistic incidence angle (30-45° ?) suggests there are places on modern MBTs that may be vulnerable to an F-35 strafing it


For a typical F-35 high-angle strafe (45 degrees, 9,000 ft) Nammo claims that APEX penetrates all of 8mm RHA NATO.
Not sure that's a meaningful increase over the PGU-32. And the PGU-48 will be superior to both.

Against enemy personnel operating on anything other than a hard surface, there's a need for a
programmable airburst or proximity round given that even very expensive, low impact velocity,
low-drag contact fuzes like the one used in the PGU-46 are going to dud.

Re: The GAU-22/A thread

Unread postPosted: 18 Nov 2018, 15:34
by steve2267
marauder2048 wrote:For a typical F-35 high-angle strafe (45 degrees, 9,000 ft) Nammo claims that APEX penetrates all of 8mm RHA NATO.
Not sure that's a meaningful increase over the PGU-32. And the PGU-48 will be superior to both.

maud, can you provide a source or link for your statement? I am not seeing the "8mm RHA NATO" penetration by the APEX (PGU-47/U). In several Nammo PDF docs, I am seeing results stated to be for 20mm RHA 45° NATO and 50mm RHA 0° NATO (first APEX PDF I attached in my first post of this thread). 20mm is 0.8". Unfortunately, I am not seeing any range distances provided for these APEX penetration numbers. A General Dynamics or Northrop Grumman (who bought ATK) PDF states 19mm RHA penetration at 0° NATO at 960m for SAPHEI (PGU-32/U). I'm not sure I've found penetration performance numbers for FAP (PGU-48/U).

marauder2048 wrote:Against enemy personnel operating on anything other than a hard surface, there's a need for a
programmable airburst or proximity round given that even very expensive, low impact velocity,
low-drag contact fuzes like the one used in the PGU-46 are going to dud.



What is PGU-46?

Re-thinking my earlier statements... I think any 25mm round is going to be hard pressed to disable, let alone destroy, a modern MBT. Maybe, if no other options are available, a mobility kill might be possible by a strafe attack from the rear or sides. Probably much better options of guiding or targeting weapons from other platforms utilizing the F-35's sensors / networked comms if SPEAR / SDB II are unavailable.

I view the 25mm GAU-22/A gun system as an improvement over the Vulcan for A2G operations, perhaps not as capable as the 27mm or 30mm rounds, but better than those in an A2A role.

Is FAP a Rheinmetal product? For some reason, I thought it was YAAP (Yet Another ATK Product).

Here is another APEX PDF I had found somewhere: APEX – Armor Piercing with Explosive The Dual Purpose Round for the F-35, Eva K. Friis, Nammo, Seattle 17.05.2012. Pages 14 and 15 have some charts giving APEX performance for a -45° dive angle from an altitude of 6500' at 550kts. Given those parameters, I am unclear on how slant range would vary (if the dive angle is specified)? Unfortunately, the axis of the figure are not given. It would appear that armor penetration is dropping with increased range.

APEX.pdf
APEX – Armor Piercing with Explosive The Dual Purpose Round for the F-35, Eva K. Friis, Nammo, Seattle 17.05.2012
(2.32 MiB) Downloaded 237 times

Re: The GAU-22/A thread

Unread postPosted: 19 Nov 2018, 02:47
by marauder2048
https://www.nammo.com/globalassets/pdfs/ammobook/nammo_ammo_handbook_aw_screen.pdf

PGU-46 is the low-drag, low-impact velocity fuzed 30x173 used on the AC-130J; even it has difficulty
with fuze functionality against dismounts on soft surfaces (soil). Just extrapolating that to 25mm ammo.

I think the PGU-48 projectile is Rheinmetall but the cartridge and propellant are GD.
Ultimately, there's an enhanced PGU-20 that's likely going to be the preferred round.

Re: The GAU-22/A thread

Unread postPosted: 02 Feb 2019, 20:28
by spazsinbad
Bad news for the internal GUN I guess; good news for the external variety though; so there is hope a fix is found for the A.
Air Force Presses Lockheed On F-35 Readiness: Lt. Gen. Bunch
01 Feb 2019 Colin Clark

"The Pentagon's independent tester reports that F-35 readiness is stuck at 60 percent, while the A model's gun is unacceptably inaccurate.

...F-35 Gun Misses Mark
The other notable fact in the DOTE report, beyond continuing problems with ALIS, the logistics and mission planning system for the F-35, is that the F-35A 25mm gun, needed for its Close Air Support role, is not very accurate. Here’s the damning language in the report:

“Based on F-35A gun testing through September 2018, DOT&E currently considers the accuracy of the gun, as installed in the F-35A, to be unacceptable. “F-35A gun accuracy during SDD failed to meet the contract specification. Although software corrections were made to the F-35 mission systems software to improve the stability of gun aiming cues, no software or hardware corrections have yet been implemented to correct the gun accuracy errors.

“Investigations into the gun mounts of the F-35A revealed misalignments that result in muzzle alignment errors. As a result, the true alignment of each F-35A gun is not known, so the program is considering options for re-boresighting and correcting gun alignments.

“During air-to-air gun testing, F-35A operational test pilots received intermittent ‘unsafe gun’ cockpit alerts while attempting gun attacks. These alerts occurred with two different aircraft; the root cause is under investigation.”

But there is good news! The F-35B and F-35C guns are accurate and “meet the contract specifications.” While the F-35A carries a permanently installed internal gun, firing through a shutter in the side of the fuselage, the B and C variants carry their gun in an optional external pod (see video below), which means it makes them less stealthy when installed, but apparently it shoots straighter."

Source: https://breakingdefense.com/2019/02/air ... gen-bunch/

Re: The GAU-22/A thread

Unread postPosted: 02 Feb 2019, 23:07
by popcorn
Strange, I would have expected the internal gun to be more accurate

Re: The GAU-22/A thread

Unread postPosted: 02 Feb 2019, 23:31
by steve2267
popcorn wrote:Strange, I would have expected the I vernal gun to be more accurate


Disappointing, but I'm ever hopeful the engineers will figger it out.

For me, the key part was:

“Investigations into the gun mounts of the F-35A revealed misalignments that result in muzzle alignment errors. As a result, the true alignment of each F-35A gun is not known, so the program is considering options for re-boresighting and correcting gun alignments."


Not quite sure how an aircraft that is so precisely designed ends up with misalignments. But it is what it is. Am guessing that if they can properly quantify where the gun is pointing on each airframe, they can Kentucky windage the sighting system for each aircraft. That is, numbers specifying a particular airframe's gun alignment, would be loaded into the flight / armament software as airframe-specific constants, which the gun sight software would use to put the '+' on the right spot.

IMO, the good news is that since the Killer Bee and SeaDragon guns are shooting within specs... there would not appear to be problems with the gun itself, which could have proved more problematic.

Re: The GAU-22/A thread

Unread postPosted: 03 Feb 2019, 00:48
by popcorn
They seem to have isolated the cause and it should be just a matter of prioritizing a fix.

Re: The GAU-22/A thread

Unread postPosted: 03 Feb 2019, 04:55
by kimjongnumbaun
In the AH-64 the targeting computer aligns the boresight of the bushmaster. I expect that aligning the gun in the F-35 would not be significantly different but it does require a few runs at the range.

Re: The GAU-22/A thread

Unread postPosted: 03 Feb 2019, 06:06
by sprstdlyscottsmn
kimjongnumbaun wrote:In the AH-64 the targeting computer aligns the boresight of the bushmaster. I expect that aligning the gun in the F-35 would not be significantly different but it does require a few runs at the range.

There is a huge fundamental difference in that the bushmaster is a gimballed weapon.

Re: The GAU-22/A thread

Unread postPosted: 04 Feb 2019, 06:02
by steve2267
kimjongnumbaun wrote:In the AH-64 the targeting computer aligns the boresight of the bushmaster. I expect that aligning the gun in the F-35 would not be significantly different but it does require a few runs at the range.


On the other hand, it may be as simply as fitting a laser pointer engineered to precisely fit in the breach of the GAU-22/A, co-aligned with the bore, and then note where the little red (or green) dot appears on a calibrated target a known distance from the aircraft. With suitably precise survey equipment, you could measure some key points on the airframe, and on the target, and then compute the necessary slop, errr kentucky windage factors, errr... airframe specific GAU-22/A installation-aiming parameters which get fed into the sighting system.

If after a few gun runs... if problems still exist... re-examine & come up with plan 9.

Re: The GAU-22/A thread

Unread postPosted: 04 Feb 2019, 12:48
by chrisben
Extreme precision is not necessarily a quality in itself, specifically in A2A. You want some dispersion.

Re: The GAU-22/A thread

Unread postPosted: 04 Feb 2019, 20:38
by wrightwing
Extreme precision is not necessarily a quality in itself, specifically in A2A. You want some dispersion.

True, but if firing danger close, you want a pretty good idea where that dispersion is going to be.

Re: The GAU-22/A thread

Unread postPosted: 04 Feb 2019, 20:57
by steve2267
Extreme precision is not necessarily a quality in itself, specifically in A2A. You want some dispersion.


I believe the dispersion is built-in to the GAU-22/A itself. The fact that the F-35B and F-35C gun pods are meeting contractual requirements tells me that the dispersion is fine. (UNLESS the gunmounts in the F-35A are loose or wobbly, which, somehow, I doubt.)

That suggests to me, and I believe some statements made in the quoted articles earlier, the issue in the F-35A is that when the gun was installed, it was somehow not identically and precisely aligned in the aircraft. But since reporting on this issue is sparse, and dubious (or just flat poor) at best, it is hard to know exactly.

Re: The GAU-22/A thread

Unread postPosted: 05 Feb 2019, 00:01
by wolfpak
It could be that the brackets the gun mounts to in the "A" allow for more flexure of the gun barrels throwing off accuracy. Might need to stiffen the brackets. Barrels move around a bit and I believe that was part of the problem on the 30mm on thee AC-130. In any event the manufacturer of a new 40mm weapon added 4 tapered splines to the barrel of it's gun to reduce flexing.

Re: The GAU-22/A thread

Unread postPosted: 04 Mar 2019, 12:38
by spazsinbad
Rheinmetall Supplies Ammunition for USAF F-35s: Working to Expand to RAAF
26 Feb 2019 SLDinfo

"...25mm x 137 Frangible Armour Piercing (FAP)… [described from earlier sources]

...In an article by Andrew McLaughlin published in the Australian Defence Business Review on February 25, 2019, the efforts of the company in Australia were highlighted. Rheinmetall Defence Australia has offered a new 25mm munition specifically designed for the F-35 Lightning II JSF to Australia.

Rheinmetall says the 25mm frangible armour piercing (FAP) ammunition designed for the F-35’s GAU-22/A gun is already in service with the USAF with the PGU-48/B designation. It offers superior lethality against air and ground targets by combining high penetration performance, versatility, reliability, low dispersion and handling safety....

...The FAP round was specifically developed by Rheinmetall for NATO F-35 operators to provide a non-depleted uranium and non-high explosive cartridge with superior lethality against armoured vehicles at extreme slant ranges, while still remaining effective against aircraft in air-to-air engagements."

Source: https://sldinfo.com/2019/02/rheinmetall ... d-to-raaf/