Gunship ideas

[r16]

the Germanic roots of Browning , now that is something I hadn't heard of yet . Any idea why they did it in 12.7 instead of 13 mm  ? I hear they had an antitank rifle of 13 mm caliber , I would have guessed they would keep it .

[Hobbes]

I suspect the current generation of gunships will be the last. With the development of small guided weapons (SDB, guided FFAR) there's rarely a need to put a trainable gun on a target anymore. Anything you can see or otherwise generate a set of coordinates for, can be hit with the same accuracy a Spectre has, and with the same range of firepower (ie the choice between small or large munitions).
The only remaining advantage of the Spectre is persistence, but if you load up something like an A-10 with SDBs you get pretty close to that as well.


re: helicopter gunships, it's always surprised me that the MH-53 had such (relatively) light armament, with just 3 machine guns (.50 or Minigun).

[Maverick]

Hobbes

Super Jolly / Pave Low were never intended to be gunships in any form.  The are what they are - CSAR platforms.  It's up to the escorting A-10s to do something about the bad guys before the Jollies get anywhere near the scene, otherwise you end up with a lot of extra personnel on the ground either dead or at the very least behind enemy lines.

The Stallion/Jolly is too big to seriously consider as an armed offensive platform, much like the Chook failed in Vietnam with 'Guns a Go-Go'.

Regards,

Mav

[Rafael]

I like the steerable gun concept. Of course, I assume that the guns would be mounted under the fuselage. Steering the gun(s) would be a CoG problem depending on the size and weight of the gun (turret(s)). So it would preclude the use of something like a 105mm.

.....Or are there designs to overcome that?

Rafa

[kitnut617]

I think Rafa, that with the clout any of the large rotary cannons have these days, 30mm's for instance, the 105's wouldn't need to be used.  I'm thinking for the QTR that two shallow ventral turrets with one 30mm and one 20mm rotary cannon in each with 360 degree coverage would be all that's needed.  I'm thinking it would be quite possible to design the airframe to have two circular frames built into the flooring right from the start so should a gunship requirement arise, there would be none of this hacking up a perfectly good transport plane, the turret rings would have a ready made frame member to be attached to.  I would have all the ammo boxes and other equipment part of the turret structure inside the hold area as a package, all of it rotating with the guns.  It all could be made to balance no matter what direction the guns are pointing. 

Of course with circular frames already built into the airframe, this could lead to other variants like an AEW, or ASW with a retractable radome.

[jcf]

the Germanic roots of Browning , now that is something I hadn't heard of yet . Any idea why they did it in 12.7 instead of 13 mm  ? I hear they had an antitank rifle of 13 mm caliber , I would have guessed they would keep it .

I need to clarify something, the Colt developed Browning M2 .50 MG does NOT have Germanic roots, while the cartridge is based on the German one the weapon itself is all Browning and is very different from, and superior to, the Maxim based T.u.F. (which BTW stands for Tank und Flieger). The .50 Browning development was started early in 1918 at the request of the US Army and is basically a scale up of the M1917  M2 .30, originally it used a Winchester developed enlargement of their 30-06 round. The T.u.F. cartridge had superior ballistics and for that reason Winchester modified it for use in the Browning design.

As to the German cartridge used in the T.u.F., it is the same cartridge as used in the anti-tank rifle, some of my sources (mostly the older ones) say it was 12.7mm - others state 13mm. Shrug, mox nix to me.

Jon

[Rafael]

I thought the use of 40 and 105mm was not only for lethality, but also for range. Is 30 mm better ranged than any of those? And is lethality equaled?

Rafa

[kitnut617]

I don't know Rafa, I thought I read that the 30mm in an A-10 could be fired from about 3 kms away with deadly accuracy, I don't know what the 40mm does or the 105 for that matter.

[Rafael]

I don't know Rafa, I thought I read that the 30mm in an A-10 could be fired from about 3 kms away with deadly accuracy, I don't know what the 40mm does or the 105 for that matter.

That's precisely what I ask. IIRC the GAU-8 Ammo is bigger than other 30mm. That, and its greater weight (at least in DU version) should count for its range, punch and accuracy. But what about the other ones?

Are they comparable?

Is a 20, 25, or 30mm gun-equipped gunship at a better standoff than with the bigger ones?

Rafa

[Jeffry Fontaine]

That's precisely what I ask. IIRC the GAU-8 Ammo is bigger than other 30mm. That, and its greater weight (at least in DU version) should count for its range, punch and accuracy. But what about the other ones?

Are they comparable?

Is a 20, 25, or 30mm gun-equipped gunship at a better standoff than with the bigger ones?

I don't know Rafa, I thought I read that the 30mm in an A-10 could be fired from about 3 kms away with deadly accuracy, I don't know what the 40mm does or the 105 for that matter.

Wikipedia states that the accuracy of the GAU-8 is around 80% of rounds fired at 4,000 ft (1,200 m) range hit within a 20 ft (6 m) radius.

That range you are mentioning is actually a "slant range" to the target.  In a direct fire application, the 30mm GAU-8 round would have a much shorter effective range.  In the situation that affords the 3000 meter range, the attacking aircraft is at an altitude sufficient for observing the target and setting itself up to shoot at the target.  Something like a 30 to 60 degree angle from the target is what you would see for the A-10 as it starts the strafing run.  This allows those 30mm projectiles to achieve their advertised performance and destroy the target. 

Something that you may not realize is that the training ammunition for the GAU-8 is just as destructive as the standard HEI and API ammunition.  I read quite some time ago that the USAF opted to load the A-10 with training ammunition to engage a number of targets in the first Gulf War.  This was apparently during the mass exodus of the Iraqi forces from Kuwait along the "highway of death" where the training ammunition effectively destroyed numerous thin skin and light armored vehicles with far less collateral damage from shell fragments. 

You might also like to know that the 30x173mm ammunition used in the GAU-8 is also compatible with the Oerlikon KCA 30mm cannon that was used on the JA-37 Viggen and other weapon systems. 

References:
Wikipedia entry for the General Electric GAU-8/A Avenger

[Burncycle]

That's precisely what I ask. IIRC the GAU-8 Ammo is bigger than other 30mm. That, and its greater weight (at least in DU version) should count for its range, punch and accuracy. But what about the other ones?

Are they comparable?

Is a 20, 25, or 30mm gun-equipped gunship at a better standoff than with the bigger ones?

The 30mm may have a flatter trajectory but it wouldn't necessarily be better at standoff with regards to penetration to the 40mm and definitely not with regards to the 105mm

It is true that gunship armament has been getting more and more powerful in response to the need to remain effective at higher and higher altitudes. In vietnam an AC-47 may orbit at 3,000 feet while a modern gunship operates near the edge of the MANPAD envelope (10,000 feet or higher). One of the reasons the .30 caliber was replaced with progressively more capable guns, and it's why the earlier 20mm vulcans were phased out in favor of the 25mm.

The Mk44 30mm cannons the USAF is planning on replacing the 25mm and 40mm with fires the same ammunition as the GAU-8 (30 x 173mm).

According to "Stolfi, Dr. R., Dr. J. Clemens, and R. McEachin, Combat Damage Assessment Team A-10/GAU-8 Low Angle Firings Versus Individual Soviet Tanks, February-March 1978, Volume 1, Air Force/56780/February 2, 1979."

In this test an A-10 aircraft attacked two combat-loaded individual Soviet T-62 tanks in five missions totaling seven passes; technicians rehabilitated the two vehicles after each pass. The aircraft were seldom higher than 200 feet in altitude; firings were initiated between 2768 and 4402 feet and terminated at ranges of 1587 to 3055 feet at dive angles of 1.8 to 4.4°. The bursts ranged from 120 to 165 rounds.

Altogether 93 DU rounds struck the tanks during the seven passes, including no impacts on one pass. The ratio of impacts to rounds fired was 0.10. Of the 93 impacts, 17 penetrated the armored envelopes for a ratio of perforations to impacts of 0.18. The report noted many of the side or rear impacts that did not penetrate the armor nonetheless extensively damaged the tanks' exterior suspension components, whereas all the rounds that hit the tanks' front caused minimal damage. These results reinforced the strategy of attacking tanks from the side or rear to optimize damage potential.

So at least in this test they only began the engagement from around ~800-930 meters and only around 17 rounds out of 93 that hit penetrated the tank from this distance (although the rest of the hits did do significant damage to exposed external parts). And that's with what we consider old T-62's. As uber as we like to think the Gau-8 is, it's nothing magical... you still need to approach from the side or rear (if high angle isn't an option) and open up pretty close. You may be able to hit the tank at 3 km away slant, but penetration would be significantly reduced.

The A-10 doesn't use APFSDS ammunition because of the danger of ingesting a sabot pedal into the engine, but on the other hand because of the position the Mk44 will be on the AC-130 they theoretically could, which would improve penetration versus the ammunition the A-10 uses (then again, increased penetration may be offset by increased slant range due to the higher operating altitude)

That being said, I would imagine against tanks they would rely primarily on the 105mm as they do now. The 30mm would probably see a lot of use against lighter structures, soft skinned vehicles and so on. I'd like to see AHEAD fuzed ammunition, although it would be more effective in 35mm due to the heavier subprojectiles.

The Air Force was looking into replacing the 105mm with a 120mm mortar at one time, which would have opened up a whole host of fun ammunition (laser guided, cluster/DPICM, HE w/ higher explosive content, etc).


*edited to include who I was responding to

[jcf]

Gunship of tomorrow. 

[LemonJello]

I'd go with the drop ship from Aliens, that'd be a cool gunship.  Replace the cargo/APC bay with a sleeker weapons pod/bomb bay for a pure attack version perhaps?

[elmayerle]

I'm doodling with doing an AH-53E, based on some discussions here some time ago.  It'd take some work, but I'm thinking the cockpit and front section of a Hind A might be useful as a design guide here, along with some of the mission equipment from a HH-53J.  I'm not sure, yet, of all the equipment fit, but it'd be an assault copter, like the Hind rather than a straight-out gunship like the Mi-28 or AH-64.

[Daryl J.]

Oddball gunship:   The Hindenberg, but helium based gas bags.



Daryl J.