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Zoner
4th Apr 2004, 04:51
From Landings:

http://www.landings.com

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."

NWSRG
4th Apr 2004, 21:10
Understand the full flaps configuration for low-speed 'water-bombing', but why would the gear need to be down?

bafanguy
4th Apr 2004, 21:26
For most transport category acft, selecting more than an approach flap setting without all gear down and locked will produce a non-silenceable warning horn. Unles they modify this 747 for the water-bombing job, the horn would be the reason for "gear down".

Zoner
5th Apr 2004, 03:26
Two of the drop tests I saw on film were at flaps 20 and gear up. I think they are doing drop tests in several different configurations to obtain the best possible dispersal pattern.

18-Wheeler
5th Apr 2004, 07:56
Sound pretty silly to me.
Yes, they carry a huge amount of water, but the problem are being able to get a lot of it out quickly enough, making sure that the centre of gravity doesn't move around too much, finding a runway that's long enough wide enough and stroung enough to take the big plane, and keeping the brakes cool enough for a turn around of less than about 45 mins or so.
747's also don't turn very well, don't climb all that well, etc.
I cant' see it being terribly useful other than one big-ish drop, then a long wait for another, and so on.

bluesafrica
5th Apr 2004, 09:03
747 may be a bit clumsy but it sure got a capacity for this kind of job!
Blues

Zoner
5th Apr 2004, 21:22
18-Wheeler: You're thinking like I did when this project started. The Gross weights will actually be pretty low as only a couple of hours of fuel is required-this isn't a long haul operation for the most part. And they have new high speed pumps which have emptied the entire load of water and retardant in only 8 seconds. The control panel will allow you to set the type of drop: all at once or segented, with varying amounts. The water has an anti-dispersal agent added to keep it in droplet form, thus making higher altitude(400-800 ft) drops feasable. And they have allready done a study of suitable runways and see no problems. I think they have really done their homework on this one.

Blacksheep
6th Apr 2004, 03:27
The really impressive bit comes later when they roll-out the water scoop variant that can refill in 8 seconds without needing to land.

Zoner
7th Apr 2004, 17:47
Here's one of the drop test videos:

http://www.everzone.org/down/highaltitudedrop.wmv

18-Wheeler
8th Apr 2004, 02:49
M'kay, after watching the video I'm mopre convinced, but not totally.
I hope it does well though!

mickjoebill
8th Apr 2004, 17:42
Is this concept more intruging post 911?

Mike B

lineboy_nz
10th Apr 2004, 06:07
Sounds interesting.
Just a general water-bombing question...
why is the water always red?

Cyclic Hotline
10th Apr 2004, 06:46
If they are dropping water, then it is clear. Most tanker drops are retardant mixed with water. Some helicopters have the ability to mix retardant in the tank or bucket, other times it is mixed in dip tanks.

If they are dropping retardant, the chemical mix is coloured with Iron Oxide and is red. Retardant consists of chemicals commonly found in argicultural fertilizers.

Willit Run
10th Apr 2004, 20:44
Sign me up!

I'd do this in a milli-second!

this ought to be fun!

mosaic
11th Apr 2004, 07:36
it's not taken into account in the performance figures !