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Luke Y
http://www.latimes.com/business/nationworl...0,5610924.story




QUOTE
SLOBODAN LEKIC, Associated Press Writer
9:54 AM PDT, June 16, 2009
LE BOURGET, France (AP) — Crop-dusters usually have the mundane task of spraying fields of grain with chemical cocktails that kill plant pests and disease-carrying mosquitoes. But a heavily modified version packs a different kind of punch — .50 caliber Gatling guns, rockets and a complement of bombs.

The unconventional plane, designated AT-802U and bearing a name that sounds like an ironic understatement — Air Truck — is part of Air Tractor Inc.'s family of ubiquitous single-engine agricultural and firefighting aircraft.

The steel-gray plane, with its prominent nose-mounted turboprop engine, looks like a sleek World War II fighter plane. It has been drawing crowds of puzzled onlookers at this year's Paris Air Show.

Where pesticide-spraying nozzles would usually be mounted — on the underside of the wings — it sports instead army-green 500 lb.-(225 kilogram) bombs, General Dynamics GAU-19/A triple-barrel heavy machine guns and multiple-rocket launchers.

The 800-gallon pesticide tank is now an auxiliary fuel tank giving it sufficient range to cross the Atlantic Ocean.

Lee G. Jackson, design engineer at Air Tractor Inc., says the idea to convert the crop-duster into a light counter-insurgency aircraft stems from a request the Olney, Texas-based company received from the U.S. government in 2002.

"They needed planes with armored engines and cockpits, and with self-sealing fuel tanks for spraying operations in Latin America," Jackson said.

Risky operations spraying jungle plantations producing a variety of illegal drugs in countries such as Colombia and Peru often entail planes dodging small-arms fire from guerrillas or narco-trafficking gangs. A number of helicopters and fixed-wing aircraft undertaking these dangerous missions have been downed by ground fire.

But the cost of dedicated turboprop-driven counter-insurgency aircraft — such as the Embraer Tucano or the Beechcraft T-6 — has reached a whopping $10 million each, and many smaller air forces have been left struggling to cope with such operations.

Jackson said he expected the price of the armed version of the crop-duster to be less than half that.

Air Tractor and its main competitor, Thrush Aircraft of Albany, Georgia, are the leading U.S. manufacturers of crop-dusting planes. They also build firefighting versions of their aircraft, with the hopper in the nose section replaced by a water tank.

Alongside its new combat-capable aircraft, Air Tractor also displayed a more traditional yellow, firefighting model equipped with massive pontoons that allow it to scoop up water from a lake or sea while skimming across the surface for a few seconds.

Jackson says that potential customers are particularly interested in the combat version's ability to loiter for up to 10 hours above a potential target area.

The Air Truck is equipped with other fighter plane features, including multiple sensors to detect incoming anti-aircraft missiles and with flare launchers to draw them off.

"One of the characteristics of the basic design (is) that we can custom tailor it to any customer's needs," Jackson said. "That's why we've had interest from some major players," including U.S. Special Operation Command.
DougRichards
Even I can remember when the Transavia PL-12 Airtruk crop duster, as the Transavia M-300, was proposed and almost got orders, as a COIN and even light maritime patrol aircraft back in the early 1980s. The idea isn't new.
Luke Y
QUOTE(DougRichards @ Sun 21 Jun 2009 2140) *
Even I can remember when the Transavia PL-12 Airtruk crop duster, as the Transavia M-300, was proposed and almost got orders, as a COIN and even light maritime patrol aircraft back in the early 1980s. The idea isn't new.


And didn't it come in handy in Mad Max? laugh.gif
GregW
I looks to me like those 50BMG gatling guns might just be inside the prop arc...

I wonder how they synchronize those? And is the ammo storage in the wing?

Very cool looking airplane (anyone else think it looks like a Sturmovik?) and the loiter time is impressive.
KingSargent
QUOTE(GregW @ Mon 22 Jun 2009 0404) *
I looks to me like those 50BMG gatling guns might just be inside the prop arc...

I wonder how they synchronize those?

Synchronizing electrically-fired guns is fairly simple, just send a firing pulse when the blades are clear of the trajectory.
Although with six prop blades the RoF will suck.
But there is no real problem...

QUOTE
And is the ammo storage in the wing?

Ammo stowage? What ammo? You mean you want AMMUNITION?!!!
DougRichards
QUOTE(KingSargent @ Mon 22 Jun 2009 0811) *
Synchronizing electrically-fired guns is fairly simple, just send a firing pulse when the blades are clear of the trajectory.
Although with six prop blades the RoF will suck.
But there is no real problem...
Ammo stowage? What ammo? You mean you want AMMUNITION?!!!


Six barrels per gun, one round each barrel, ie six rounds per gun, ie, one per propellor blade.....
DanielStarseer
QUOTE(DougRichards @ Mon 22 Jun 2009 0409) *
Six barrels per gun, one round each barrel, ie six rounds per gun, ie, one per propellor blade.....


Those are GAU-19's, 3-barrel 50-cals, not 6 barrels.
And looks are deceiving: from the front view, the guns are outside the propellor arc.

These planes, as "AgWagons" and crop dusters, stored some of their various chemicals (pesticides mostly, fertilizers, etc) in tanks not only in the fuselage, but also in wing compartments separate from fuel (don't even know if this particular aircraft actually has a "wet" wing containing fuel under normal agricultural circumstances, but the endurance suggested for a military version would almost imply it)...
So it makes sense then that any slung guns could be fed from in-wing magazines.

The AirTractor home page goes in detail of the various civil models, but is lacking in anything good pertaining to the armed concept,
although I must admit: the twin-float water bomber looks wicked slick,...even though its drag penalties must reduce even further its rather meager 180mph speed (which I'll admit, seems woefully lacking for a fixed wing combat aircraft, again you strap high-drag ordnance on there).

As for those GAU-19 miniguns: the impact area (CEP? dispersion?) at range must be horrific: just how stable can those guns be, mounted to pylons like that? Didn't the US discover that podded Vulcans sucked as far as accuracy was concerned, so went to an under-nose mount fixed rigidly to the airframe of later F-4 Phantoms, and have rigidly mounted such guns ever since?

I'd be curious to see accuracies when comparing the GAU-19 to other weapons, most notably the single-barrel M3P 50-cal that fires at ~1000rpm, even though advantage goes to the rotary gun in that duds are ejected as easily as spent casings,
and being externally powered, a dud or misfire won't permanently jam the gun for the remainder of the flight, as it'll just cycle thru.

Points to AirTractor for trying, though.
But 180mph, seriously?
Rather sluggish, ain't it?
Would it really be worth something more than a helo, which can VTOL where this cannot (even respectable STOL still isn't VTOL), and can hover to scout and guide or designate weapons?

These aircraft converted from innocent civilian to military predator aren't new, definitely not.
Take a look-see here at some previous attempts in up-arming counter drug "anti-agriculture" aircraft, and note their speeds in the neighborhood of 250mph.

Shucks, be further off dusting off the designs for hotrods like the Mustang-look-alike Cavaliers and Piper Enforcers...
How many of those post-WW2 (with the advent of the first turboprops) propfighters would do stalwart performance today in any number of brushfire wars and counter-insurgencies where your adversary has no air force assets whatsoever?

(And no, these prop planes wouldn't be so highly vulnerable to AA fire and MANPADS...because helicopters proliferate in places like Iraq and Afghanistan and aren't getting swatted out of the skies like flies on a regular basis by the insurgents' hordes of AAA. So the argument that slower (slower than jets) prop-driven COIN aircraft being too vulnerable is moot. dry.gif
But there again, if helos are surviving and many of them can't even achieve 200mph clean, I suppose this 180mph idea isn't a total waste...)

Pull the pilot out, make it remote control, and call it an armed UAV; it'll sell like hotcakes. laugh.gif

Time to wake up Burt Rutan, show us what an armed EZ will look like.
Maybe we can start marketting homebuilt kits to The Gub'ment, with all manner of hardpoints to sling Javelins and the like, mount a minigun in the forward luggage compartment, maybe...


$.02
shep854
Weren't there some planes resembling aerial applicators (the 'proper' term wink.gif ) in the pix of the recent Gaza ops? Not for CAS, but perhaps as an inexpensive observation platform? After all, the Israelis are no slouches in the improv department.
Chris Werb
QUOTE(DanielStarseer @ Mon 22 Jun 2009 1132) *
(And no, these prop planes wouldn't be so highly vulnerable to AA fire and MANPADS...because helicopters proliferate in places like Iraq and Afghanistan and aren't getting swatted out of the skies like flies on a regular basis by the insurgents' hordes of AAA. So the argument that slower (slower than jets) prop-driven COIN aircraft being too vulnerable is moot. dry.gif


Helicopters can hover and deliver cannonfire or precision weapons from above/out of range of most drug cartel/terrorist air defences (in UK use that's what they actually tend to do). A fixed wing plane armed with fixed fifty calibres, unguided 70mm rockets and dumb 500lb bombs is, of necessity, going to be getting up close and personal so the argument that slower (than jets) prop-driven coin aircraft are too vulnerable is IMHO still valid.
baboon6
Interesting post by an RAF officer on ARRSE on the pros and cons of the Air Truck:

Pros:

1. Robust design offers genuine rough field capability (which, despite the sales brochures, even fast turbo prop types such as the STuc lack).
2. Relatively decent payload.
3. Some potential for ISR.
4. Low operating costs.
5. Err, can’t think of much else really!

Cons.

1. Painfully slow Unmanned Air System (UAS – we’re not allowed to call them UAVs anymore!) speeds so unable to conduct a Show of Force (SoF) at low level (probably the most common form of ‘effect’ employed by CAS assets) without being extremely vulnerable to ground fire. If it did do one, it’s fair to say the TTWBGs probably wouldn’t be all that intimidated! The slow speed would also severely limit it’s capability to be retasked (do not underestimate how big a place the Stan is). At least a STuc can do a SoF at around 300kts and make a bit of noise.

2. Extremely limited range and therefore endurance.

3. Limited weapons options (unless you want to pay for it!). Given the speed of the beast and the altitude it would need to descend to to engage with the guns and grenade launchers, it’s vulnerability to ground fire is again emphasised. To be honest, it also suggests that the Company's understanding of the CAS mission is tenuous at best.

4. No de-icing systems that I can see. So that’ll be a predominantly clear weather, no icing asset then!

5. I suspect no oxygen system either. Again that means it’ll be unable to climb over the often scary Afghan weather.

In short, the AT-802U is not a credible CAS asset for anything beyond dropping bombs on a drug factory in the Columbian jungle imho. It has a degree of utility as an ISR asset to augment smaller UAS such as Hermes 450/WK. Its advantages in this area would be greater payload but lower costs, manpower and J6 requirements. Conversely however, its endurance is very limited indeed.


http://www.arrse.co.uk/Forums/viewtopic/p=...31.html#2629131
Kensuke
QUOTE(DanielStarseer @ Mon 22 Jun 2009 1032) *
As for those GAU-19 miniguns: the impact area (CEP? dispersion?) at range must be horrific: just how stable can those guns be, mounted to pylons like that? Didn't the US discover that podded Vulcans sucked as far as accuracy was concerned, so went to an under-nose mount fixed rigidly to the airframe of later F-4 Phantoms, and have rigidly mounted such guns ever since?


Not quite. There's a big difference between 12.7mm and 20mm. 2000 rpm and 6000 rpm. And IIRC, the problem with the SUU-23/A had a lot to do with its poor accuracy in engaging air to air targets and the fact that it was rarely boresighted properly.

Very few COIN aircraft have fixed guns. They tend to be pod mounted affairs. The OV-10A and A-37 Dragonfly use a variety of gun pods, including varients of the M61 Vulcan. The only COIN aircraft I know of that is still in production and has internal guns, is the A-29 Super Tucano. It has a pair of wing-mounted M3Ps, ala a WWII fighter. It also costs 10M a pop and might be more than some people really need.

QUOTE
I'd be curious to see accuracies when comparing the GAU-19 to other weapons, most notably the single-barrel M3P 50-cal that fires at ~1000rpm, even though advantage goes to the rotary gun in that duds are ejected as easily as spent casings,
and being externally powered, a dud or misfire won't permanently jam the gun for the remainder of the flight, as it'll just cycle thru.


"Maximum dispersion of 5 milliradians diameter for 80% of the rounds fired."

It also seems to indicate that the GAU-19 was specifically designed for light aircraft.

http://www.navweaps.com/Weapons/WNUS_50cal-GAU-19_MG.htm

Incidently, .50 cal is probably the ideal COIN gun armament (don't tell pfcm). I read that the 7.62mm has difficulty penetrating thick jungle foilage, while 20mm is not worth the ammo tradeoff if you intend to use FFAR anyhow.

- John

- John
Doug Kibbey
QUOTE(Kensuke @ Mon 22 Jun 2009 2053) *
Very few COIN aircraft have fixed guns. They tend to be pod mounted affairs. The OV-10A and A-37 Dragonfly use a variety of gun pods, including varients of the M61 Vulcan.


A-37 Super Tweet was also available with a nose-mounted fixed minigun. (picture in link). VNAF in my neck of the woods were mainly armed with the nosegun and FFAR's.


"The 20mm GPU-2/A and AMD 30mm cannon pods were tested with favorable results on the A-37B, [1] but reports indicate that such pods were rarely or never used in operation."


http://en.wikipedia.org/wiki/A-37_Dragonfly

shep854
QUOTE(Doug Kibbey @ Mon 22 Jun 2009 1730) *
A-37 Super Tweet was also available with a nose-mounted fixed minigun. (picture in link). VNAF in my neck of the woods were mainly armed with the nosegun and FFAR's.
"The 20mm GPU-2/A and AMD 30mm cannon pods were tested with favorable results on the A-37B, [1] but reports indicate that such pods were rarely or never used in operation."
http://en.wikipedia.org/wiki/A-37_Dragonfly


The OV-10A (at least as used by the Marines and Navy) had four sponson-mounted M60 MGs. The AF variant was unarmed, except for smoke rockets, lest Congresscritters mistake them for Phantoms.
Doug Kibbey
QUOTE(shep854 @ Mon 22 Jun 2009 2242) *
The OV-10A (at least as used by the Marines and Navy) had four sponson-mounted M60 MGs. The AF variant was unarmed, except for smoke rockets, lest Congresscritters mistake them for Phantoms.


I never saw any Bronco's operating there myself, but quite a few Dragonflys and our own Mohawks (armed somewhat in excess of what was strictly called for by "target marking"). wink.gif
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