Interesting article from Aviation Week:





U.S. Marines Eye Late Summer Fielding of Armed KC-130J


Aviation Week & Space Technology May 25 , 2009
Amy Butler
Washington



Though some special ops tools are top USAF unfunded priorities for 2010, gunship plans languish

As the U.S. Marine Corps moves ahead to field a gunship kit for its KC-130J refuelers, the Air Force’s strategy for its own gunship appears to have stumbled.

Despite earlier efforts from Air Force Special Operations Command (Afsoc) to begin work on a C-27J gunship variant, dubbed the “Stinger II,” no funding was included in the service’s Fiscal 2010 budget request. Gen. Norton Schwartz, Air Force chief of staff, says the most likely scenario will call for outfitting Afsoc’s existing MC-130Ws with armaments. They will not likely carry all of the equipment, including a 105-mm. howitzer, 40-mm. cannon and 25-mm. gun, used by the AC-130H/U fleet. However, they are expected to have some armaments, possiby including the 50-lb. Special Operational Precision-Guided Munition (SOPGM), a weapon being considered for use on small, fixed-wing systems and rotorcraft. Afsoc has already tested this weapon on the AC-130U (AW&ST Mar. 16, p. 30).

Afsoc has 12 MC-130Ws, which are C-130Hs outfitted with refueling capability and specialized defensive and navigation systems; these modifications are designed to allow the aircraft to conduct covert infiltration/exfiltration missions as well as provide refueling for special ops helicopters and the CV-22.

Special operations and communications equipment are among some of the items on the top of the U.S. Air Force’s $1.9 billion Fiscal 2010 unfunded priorities list, though a gunship isn’t among them. In his wish list, Schwartz outlines a need for two HC-130Js, which would provide refueling capabilities for combat search-and-rescue (CSAR) forces in Europe and Africa; commands there now lack this capability, as many resources are being diverted to support operations in Afghanistan and Iraq. Schwartz says $158 million, the fifteenth item on his list, would accelerate the purchase of two HC-130Js.

Also for Afsoc, Schwartz outlines two items for the HH-60G Pave Hawk CSAR fleet. The Air Force hasn’t been funding replacement helicopters for combat losses of Pave Hawks because they were expecting to move forward with the CSAR-X, a program to procure replacements that has come under fire after multiple bid protests. But Defense Secretary Robert Gates dashed that effort, demanding the Pentagon to move forward with a new approach to CSAR that could include using existing special ops helicopters for the mission, or possibly buy an airframe suitable for multiple military services.

Vice Adm. Steve Stanley, Joint Staff force structure and resources director, said during the Fiscal 2010 budget briefing that the V-22 may be a suitable platform for this mission. Bell/Boeing had hopes of capturing the CSAR-X program years ago with an Osprey offering, largely based on the CV-22 being delivered to Afsoc. It was deemed too expensive, and Boeing dropped the V-22 option in favor of the CH-47 Chinook-based proposal.

Schwartz, however, asks for $120 million as Item 12 in his unfunded priorities list to pay for full funding of three HH-60Gs; the service requested funds in the Fiscal 2010 budget for two UH-60M variants used by the Army that would later be converted to the Pave Hawk variant. Also, Item 5 is for $81 million to procure 81 AAQ-29 forward-looking infrared sensors for the Pave Hawk fleet; the legacy AAQ-16 is no longer supportable, Schwartz says.

As the Air Force focuses on augmenting the special operations fleet and considers gunship options, the Marine Corps is moving ahead with acquiring an intelligence, surveillance and reconnaissance pod and armaments for some of its KC-130J refuelers.

Lockheed Martin was awarded a $22.8-million sole-source contract this month by the Marines to develop the “Harvest Hawk,” or High-Altitude Weapon Kit, upgrade. The service had hoped to begin work last year, but the program was on hold until Congress approved the new start in March.

The Marines plan to field a kit that rapidly reconfigures the KC-130J into a fire support and targeting platform that would aid the Marine air/ground task force commander overseeing soldiers on the ground, says Maj. J.P. Pellegrino, KC-130 requirements officer for Marine Corps headquarters.

“We are not trying to take away from the primary mission of tanking,” he says. “We are not trying to build an AC-130. That has never been our purpose.” The AC-130H/U provides highly precise fires to support soldiers and special operators.

The kit for the Marines includes the Lockheed Martin Targeting Sight System designed for use on the AH-1Z Super Cobra helicopter and a Flir and laser designation capability.

The threshold weapon for the Harvest Hawk system is the Hellfire II, most likely the AGM-114M variant employing a blast-fragmentation warhead, Pellegrino says. However, an anti-armor variant is also available for integration on the KC-130J. Eventually, the Marines may add the SOPGM to the airframe or, possibly, a 30-mm. cannon. The Hellfire II would provide precision fires suitable to attacking a vehicle or small group of insurgents. The 30-mm. cannon is desirable as a fire suppression system.

Afsoc tried the 30-mm. cannon on its AC-130H/U gunships, but was unable to achieve appropriate precision; so officials there kept the 40-mm. and 25-mm. guns on the Air Force gunships. “We are not looking at sniper accuracy,” as is Afsoc, Pellegrino says. “We are looking at suppressive fires.”

With the exception of the 30-mm. cannon, the ISR system and Hellfire II will allow the KC-130J to continue operating at its typical altitude of 20,000-25,000 ft. This is also above the range of infrared threats. “We will provide overwatch any time of the day because we are not going to be afraid out there above the infrared threats,” Pellegrino says. Incorporation of the cannon could force crews to operate at lower altitudes.

The Marine Corps plans to buy one development Harvest Hawk unit, and has approval to purchase three more under the existing contract with Lockheed Martin. The initial flight test is slated for mid-June, and the first deployment is expected in late summer.

A request for funding for the final six is included in the Pentagon’s Fiscal 2010 Overseas Contingency Operations request, which is aimed specifically at supporting war operations.

The Marines expect to assign three Harvest Hawk units to each KC-130 squadron; the first sets will go to the service’s active-duty squadrons by the end of Fiscal 2011, Pellegrino says. The kits are designed to be integrated rapidly onto any KC-130J in the fleet. Thirty-four of 79 KC-130Js have been delivered to the Marine Corps.

That's interesting - the first official explanation I've read as to why the plan to re-equip the AC-130s with the 30mm MK44 was dropped.

Next question: since the MK44 is, on a firing range, at least as accurate as the 40mm Bofors and 25mm GAU-12/U (probably more so), why couldn't it achieve that accuracy when fitted to the aircraft?

The lack of accuracy they've apparently observed with the 30mm MK44 was reported last year in a couple of articles by Amy Butler of Aviation Week :

It was mentioned in the previous gunship thread, can't remember the specifics though.



What I have trouble understanding is why the CV-22B can't be used as the CSAR-X replacement?
What does it not do that the requirement called for?

Another article from Inside The Air Force :

FOR FAIR USE

My understanding is that the CV-22 essentially priced itself out of the competition.

Thanks for the info about the MK 44 problem - but I'm still puzzled. I've never read any criticism about the accuracy of the gun before, and the suggestion that the projectiles are too small doesn't seem right since they still have the 25mm gun in some planes. Perhaps the mounting wasn't stiff enough, although that would seem an unlikely error.

It has still got to be cheaper than sinking all that cash into a whole 'nother aircraft R&D program and associated cluster-f*ck, not to mention the potential log costs of another airframe though no?

That's possible, although I have no idea of how the costs would work. IIRC, Bell/Boeing admitted that the Osprey didn't have much of a chance purely on cost grounds, and didn't raise much of a fuss when the aircraft was eliminated from the competition.

Can anyone explain why they don't replace the 1940's 40mm guns with some of the new L70's that are currently used? Is there something about the L70 that makes it unsuitable?





-K

Wonder if this could be adapted for the AC-130 as a 40mm replacement?:

http://www.baesystems.com/ProductsServices...m_mk_three.html

I assume they just used what they had in stock.

The Royal Navy did the same: unlike the British Army, they never adopted the Bofors L/70 and kept the old L/60s in service into the 1990s.

The RN adopted the 40/70, single, twin and sextuple mounts featuring on many designs of the early post war period. At this time the L70 was credited with an effective range of 5000 yards and it was hoped standardisation could be achieved across UK forces. DGD argued that the high RoF would make up for limited lethal effect of each round. According to Friedman the proposal foundered because then extant 40mm rounds were ineffective against 1/2 and 1/4" plating used on small surface craft and submarine superstructures of the period. The alternatives considered at the time were the 3.3" coastal forces weapon (Friedman says adapted 17 pounder but IIRC a 20 pounder) and a variety of 4" weapons (Mk 19, Mk 25 and Vickers Venture). The 4" was adopted for the coastal frigate because a true DP gun was demanded. Attention then focused on the 3"/70 for AA use. This was a fairly massive installation that as a result only (IIRC) went to sea on Tiger class frigates with the RN the close AA defence role on other vessels passing to Seacat.

*Engage Threadjacker 2000

I find it interesting that the 40mm was considered ineffective against armour that was just 12.7 mm or 6.35 mm thick.

From the little that I know of the US 40/56 Bofors, its armour piercing performance was similar, or somewhat better, than the British 2 pounder of 1939-1942 usage, which was quite a decent hole puncher.

I know the UK developed and produced a SAP and a dedicated AP round. The little information I can find suggests the UK SAP round achieved 25mm penetration at 1,300 years with a 30 degree offset. The USN AP shell shell did 69 mm at point blank, 30 mm at 2,000 yards and 11 mm out to about 6,000 yards.

Additionally, was the automatic 6 punder ever considered as an AA weapon? It fires a much heavier shell than the Bofors, although the RoF and MV would definately qequire working on.

**Disengage Threadjacker 2000

The RN wanted to adopt the 40mm L/70 but it never got into service. The Tiger class cruisers were intended to be completed with "twin Bofors L/70", according to Friedman (The Postwar Naval Revolution) but "The ships were only completed with the 6in and 3in guns, as the L70 Bofors never appeared."

Not the MV - that was pretty much the same as the 40mm L/56. RoF was only c.60 rpm though. A more obvious choice would have been the 57mm Bofors, which was as powerful as the British 6 pdr but fired at 120 rpm. It was introduced in 1950.

USAF is still shopping for 40mm hardware:


https://www.fbo.gov/index?s=opportunity&...re&_cview=1

Seems like this then might be the perfect opportunity for BAE to mobilize their CTA 40 Influence Group and try getting the USAF to trial the 40mm CTAI gun.

If the 30mm Bushmaster was seen as lacking in accuracy (as far as the USAF requires accuracy, which is...?), then I wonder if the same gun might be the wisest choice of armament for the USMC's EFV (in whatever form it finally ever emerges), or the USN's new Mk46 gun mount, or for that matter, the armament for the now-defunct FCS IFV and planned upgrades to the Bradley.

This might be a prime opportunity for BAE to push the 40 CTA to the US military (which the 40 CTA already has been trialled in a turret on the Bradley),
providing its accuracy can be proven to be no worse than the 30mm, and at least on par with the current gunships' 40mm
(is that elderly design really superior in accuracy to a modern cannon?).

If it's rate of fire they desire, I'm sure BAE can work out a new feed mechanism for the 40CTA that allows it so:
the current 90 degree rotating loading/breech feature of the CTA gun may not lend itself well to higher rates of fire as can be achieved with Chain Guns and recoil-operated autocannon like Bofors and Mauser/Rheinmetall pieces.

Perhaps a 35mm Millennium with AHEADS ammo instead to replace the 25mm and 40mm?
(or dual-fed with HEDP as the other round?)
Perhaps the 40 CTA's unique ammo would lend well to a revolver-type cannon mechanism (although I wouldn't expect such high rates of fire as the Millennium Gun's 1000rpm burst)....?

At one time they were looking into replacing the 105mm with a 120mm mortar, which seems like it would offer some advantages (greater HE filler, guided ammo options, cluster munitions) but I dunno what happened to it.

I don't think that rate of fire is an issue, as the 30mm MK 44 they wanted to use fires at 200 rpm - the same as the 40CT.

I suspect that they'll stick with the 40mm L/60 rather than adopting any other 40mm because it's a proven system and it does the job. Adopting anything new involves a lot of work and expense - and there may be unforeseen problems as they found with the MK 44.

I'd still like to get chapter and verse on exactly why the MK 44 proved so inaccurate; I can't offhand find any accuracy claims for the gun, but I think that on a test stand it's likely to be more accurate than the Bofors.

Check out page 65 of the same book for why the 40/70 never appeared.

Tony, I think you'll agree that any inaccuracy is far more likely to be due to the mounting, airframe rigidity, FCS etc. than to anything inherent in the weapon or its ammunition.

Threadjacking slightly, I read somewhere (Hogg?) that in the latter years of its service, the twin six pounder coastal gun was adapted to give it a dual coastal AA role. I find this hard to believe. For one thing the emplacements would offer limited arcs of fire and I'm not aware of any ground to air radar or FCS being employed with this system or proximity fused ammo being deployed. OTOH mobile 3.7" HAA guns definitely were deployed in a mobile coast defence role in the 1950s (presumably with their fuse setter rammers removed as in NZ but I still have to confirm that). The only sensible explanation that I can come up with is some kind of modification to the sights to enable it to engage low level/slow aircraft engaged in minelaying. However, again, the guns tended to be deployed to cover the approaches to anchorages, not the anchorages themselves. I'd be grateful if you could throw some light on this Tony.

Yep, I did.

Hogg refers to a development programme at the end of WW2 for a 6pr 10cwt with an 80 degree elevation to act as a DP gun, but it seems that this was subsumed into the 6pr 6cwt automatic gun, which was seen as a DP (AA/coastal) equipment.

Yes, there may be some sort of unforseen, uncorrectable harmonic between the gun recoil, mount and airframe that causes the POI to wander unacceptably. It would be interesting to learn if the problem arises in another airframe.

Yes, I've seen pics of a mock-up or prototype of that one (again in a Hogg publication) but I have also seen references to the coastal twin sixes being modified. I think you've found the likely source of the confusion assuming the coast guns were never modified for AA work.