From Landings:
747-firebomber
Stand by for the 747 “Supertanker,” the world’s largest aerial firefighter.
The folks at the Evergreen Air Center Pinal Airpark in Marana, Ariz. have also done a lot of work for the U.S. Forest Service and Bureau of Land Management. But they may have outdone themselves with their latest project: a Boeing 747 firebomber called the Supertanker.
It’s a former cargo plane outfitted as an aerial firefighting aircraft. The plane carries 180,000 pounds of water in a 24,000-gallon belly tank, said an Evergreen spokesman.
The water-drop testing was done, according to an FAA Notam, from Feb. 15 through Mar. 15. The world’s largest air tanker operated VFR within 10 n.m. of Pinal Airpark, making drops near the airfield at altitudes from 10,000 feet msl down to 800 feet agl.
Evergreen has not yet released the results of the testing but it has high hopes for the 747 Supertanker.
With its patented, pressurized drop system, the Supertanker can disperse retardant under high pressure, allowing it to drop from an altitude of 400-800 feet, versus 200 ft. for most of today’s tankers. It can also drop its entire load in eight seconds, or in several segmented drops, Evergreen said.
The Supertanker’s drop speed will be around 140 knots, which provides a 30% cushion above its stall speed. During drops, it will be configured as it would be for an approach to land, with gear and flaps down.
Tanker Experience
Evergreen Aviation has long been known for its involvement in oddball aerial experiments for the CIA and other government agencies.
One of its most well known schemes was putting a Fulton aerial retrieval system in the nose of an Intermountain Aviation B-17 in the 1960s. The plane and the “Skyhook” system were featured in the 1965 James Bond film “Thunderball.”
Evergreen’s experience in aerial firefighting dates back to 1960, when it formed Evergreen Helicopters, which today operates 54 helicopters, 30 of which are configured as tankers. It got into fixed-wing tanker operations when it purchased Johnson Flying Service of Missoula, Mont. in 1975.
Aeronautical engineers spent more than 20,000 hours developing the Supertanker, Evergreen said. Boeing supported preliminary engineering studies and the certification of components, and will be involved in the FAA certification process.
The choice of aircraft was based on Evergreen’s vast experience with the 747. Its fleet of 10 747s have logged more than 416,000 hours in the air over the past 25 years.
The Supertanker is an attempt to update the air tanker fleet, which consists mostly of ex-military transports, some of WW II vintage. Unlike most of the current tanker fleet, the 747 will fly within its original design envelope, Evergreen said.
Evergreen contends that the Supertanker, with a cruise speed of 500+ mph, will be able to put out fires in less time and require fewer aircraft and flight hours. Its 24,000-gallon load of retardant is seven times larger than that of the most modern tanker, the Lockheed P-3 Orion.
What becomes of the Supertanker depends on the results of the drop tests. Although testing of a Douglas DC-10 air tanker in Southern California last year led nowhere, Evergreen has the experience and financial backing to make this project work.
If it is as successful as hoped, it could cut the size of the air tanker fleet significantly. Or as Tony Kern, the U.S. Forest Service’s top aviation official, put it: “You’d never see a fleet of 20 of these things but you might see a fleet of 10.”
By: Bmused55 - 8th April 2004 at 07:38
Originally posted by steve rowell
It doesn’t seem feasible to me, can it fly low and slow enough to be useful in this role as a fire tanker
Well to be frank, it doesn’t have to seem feasable to us. They couldn’t give a rats arse what you or I think.
If the trials prove its worth doing, it’ll be done.
By: steve rowell - 8th April 2004 at 03:26
It doesn’t seem feasible to me, can it fly low and slow enough to be useful in this role as a fire tanker
By: Tim Green - 8th April 2004 at 02:07
Well, you have a point about Evergreen.
Much of Evergreen’s developement costs have been funded in part by the U.S.Government. Their reputed ties to CIA and NSA projects have been rumoured over the years – similar to the Air America project in S.E. Asia in the 60’s & 70’s.
But what benefit those worthy organizations would gain from a 747 water bomber? Heaven only knows.
Have a Happy Easter everyone.
By: wysiwyg - 7th April 2004 at 23:20
Yes, that’s what I was trying to say. There are many learned people involved in this project who would have pulled the plug long ago if it was not viable.
By: Bmused55 - 7th April 2004 at 07:36
Originally posted by Tim Green
Knowing absolutely nothing about it – I am going to comment anyway.It appears to me that aerial water bombing, to be effective, would surely have to be done low and slow and also in incredibly severe conditions of turbulence, smoke and ash.
The 747 would have to deploy all of it’s (leading edge) lift devices and probably at least 10 degrees trailing edge flap. This would result in tremendous wear and tear on those delicate parts and the associated expense. And as for FOI (foreign object injestion) into those jet engines ……. All we have to do is read up on the BA 747 in Bali to see what ash can do to a jet engine. Just think of whole branches being sucked into those old P & W’s! I cannot think of a more unsuitable Aircraft unless bombing from a great height and what effect would (even) a 747 load have from 5,000′?
The old twin/four engine recips seem best. Long live the DC6 and variants!
Well, look at it thisa way.
If it was that unsuitable, why spend all the money on reseaching it.
Clearly, there are more benefits that disadvantages… or else this program would have died off ages ago.
By: Tim Green - 7th April 2004 at 05:28
Knowing absolutely nothing about it – I am going to comment anyway.
It appears to me that aerial water bombing, to be effective, would surely have to be done low and slow and also in incredibly severe conditions of turbulence, smoke and ash.
The 747 would have to deploy all of it’s (leading edge) lift devices and probably at least 10 degrees trailing edge flap. This would result in tremendous wear and tear on those delicate parts and the associated expense. And as for FOI (foreign object injestion) into those jet engines ……. All we have to do is read up on the BA 747 in Bali to see what ash can do to a jet engine. Just think of whole branches being sucked into those old P & W’s! I cannot think of a more unsuitable Aircraft unless bombing from a great height and what effect would (even) a 747 load have from 5,000′?
The old twin/four engine recips seem best. Long live the DC6 and variants!
By: wysiwyg - 6th April 2004 at 02:33
I don’t think we really need to worry too much about whether it’s safe or not. They have had to jump through one or two fairly stringent hoops so far! Fortunately they mostly don’t allow idiots to do aviation engineering!
By: brenmcc1 - 5th April 2004 at 13:56
I cant see it working very well.
By: coanda - 5th April 2004 at 13:47
depends on where you dump it from.
is this a windup?
coanda
By: Jeanske_SN - 5th April 2004 at 10:20
Dumping 150 tonnes in eight seconds would result in the plane going up because of the loss of the load! The aircraft would veer up! How many tonnes can it load?
By: Warhawk - 5th April 2004 at 01:28
I can see a problem with it right now. If it get’s final approval people are going to be setting forest fires all over the country in hopes of seeing it in action.:eek: 😀
By: Whiskey Delta - 4th April 2004 at 20:33
I would like to see footage of the drop test from 800′ AGL. 🙂
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April 4, 2004 at 8:21 pm