I was intrigued by the mention of a 747 "heavy tanker" involved with fighting fires in NorCal so I started watching YouTube videos. One thing I was wondering....how does the water-dropping work? From watching the videos, the water looks to really spread out and dissipate as it nears the ground. Doesn't seem like it'd really snuff the fire out.

Anyone familiar with that stuff? Still pretty impressive seeing a 747 doing low-level bombing runs. LOL

The water is mixed with a fire retardant called PhosChek. The retardant keeps the fire from spreading and is died red so that pilots can see where it's been dropped. They don't drop the Phos-Chek directly on the fire.

The video I saw (in Spain I think), it was just water. Came out white.



And does it drop the whole load at once, or can it turn off/on the water? LOL

Water alone, helps cool the fire and reduces it's intensity, that helps the guys on the ground work the "lines" (breaks in the fuel) and in isolating the progress of a fire's movement.

My cousin who is lives on the Res in Browning MT, used to be in the Chief Mountain Hotshots.

There is a whole lotta stuff going on that you cannot see during these fires.

God bless all affected in every one of them.

Most large tankers can drop water/retardant from separate tanks or dump all at once IIRC.

From experience, I can tell you that although water looks very dispersed when a tanker drop occurs it is very much wet when it arrives. Looks can be deceiving- it might look like a fluffy cloud of mist from a distance, but it is a deluge.

As SM said, the goal isn't to directly put out fire. You could do a drop on a fire, leave it alone, and if you're in prime burning conditions (low humidity, low available moisture, adequate fuel load) the fire will be back given enough time. The wildland firefighters are a huge component of killing fire that is damped down by water drops.

Many of these heavies are based at MCC in Sacramento. They were coming and going frequently when I was there the other day. I believe some of the retardant also has fertilizer to help revegetate the area as well. They have MD80’s, DC10’s, and B747 there. ( corrected )

This message has been edited. Last edited by: coloradohunter44,

I saw the 747 yesterday around 6 pm coming back to McClellan AFB (former). The glide path for these tankers is near my house so I see quite a few this time of year. Now that McClellan is open to the public, you can essentially drive right up the flight line and staging area. I saw it a year ago and was 100 yards from the parked 747. Massive little toy.

I spent over 25 years doing aerial firefighting in heavy tankers (LATs), single engine air tankers (SEATs), air attack platforms, point to point, fire patrol, and six years of fighting fire on the ground.

Air tankers are not used to put fire out. That is to say, ground troops put fires out: air tankers are used as tools by the ground forces to effect specific goals or support ground operations. Putting a fire out from the air with direct application of water or retardant is impossible in many cases, and not an effective use of expensive air assets. While water does get used, it's not used often as a stand-alone agent; there are numerous chemicals dropped on fires, with a number of different fire retardants in use present and past being the majority of what's dropped. It may come out red or pink, orange or yellow, or in the case of certain gels, blue, and water typically appears dark or white, depending on the lighting.

A drop is conducted at an altitude which ideally allows the retardant to stop its forward motion and fall straight down. If it falls at an angle, one side of the fuel (what's burning, or might burn) will be coated, while the side opposite the drop will not; the fire will pass through those fuels and the retardant may be less effective or ineffective.

Retardant is dropped by "coverage level." That is, gallons per hundred square feet. The air attack (an experienced firefirefighter orbiting the fire above) or incident commander will request a specific coverage level based on winds, terrain, fire behavior, fuel density, effectiveness of previous drops, and other factors, and the tanker will set up the drop to perform at that level. Coverage level 4 is four gallons per hundred square feet, coverage level 8 is eight gallons, and so on. Generally eight is the maximum coverage for a large air tanker, and the VLAT (DC10, and B747) can go a bit higher).

Stopping forward motion of the retardant is often not possible; maximum coverage of the fuels and penetration through the fuels is what's desired, with enough aeration occuring in the retardant as it hits the slipstream, coming out of the tank to provide adequate fuel coverage. That said, there's still enough force from the retardant to dig a channel in the earth, overturn vehicles, and kill people. This last year, the government released a training video showing vehicles badly damaged by retardant, by placing the cameras in the vehicles, to keep ground troops informed of the consequences of getting too close.

Ideal drop results occur over level ground, for uniform drop pattern and coverage, straight lines, constant drop height above fuels and terrain, etc. Drops are rarely over level ground, however, with terrain rising and falling, and thus drop height varying, changing the retardant pattern at the surface. Fuels vary, and winds are often erratic and violent over the fire. Aircraft drop down hill and down-canyon, resulting in speed increase, which also changes coverage.

Retardant is used to direct fire behavior, rather than put it out. Sometimes it's dropped direct, or "half-in, half-out," meaning to put it on the fire line with retardant in the burn ("the black") and in the unburned ("the green"). Much of the time, however, retardant is applied indirectly to slow fire advance, pre-treat the back side of a ridge to prevent fire slop-over, treat along the green side of a fire break under construction, or ahead of ground troops or dozers to allow time to construct line or support lines. Retardant is also used to create safety or escape zones, and is often used to tie into natural barriers such as ridges, rock outcroppings, water features (lakes and rivers) roads or low fuel density areas, to direct the fire progress to an area where it can stop.


Wildland fires contain more energy than a nuclear weapon, dispersed over time, and contain too much heat and energy to put out, in many cases. Not enough retardant could possibly be dropped to do it, and smoke and visibility restricts where drops can be made, as do winds and terrain. The effort is not to stop a fire with aerial attack, but to slow it, modify it, or ideally, stop its advance in a particular direction. That said, I've seen fire reverse course or cross HEAVY retardant lines, as if they weren't there, or spot across them with winds and burning materials aloft, and keep on trucking.

There are no seeds in retardant. Seeding operations are done after fires are over, usually in the winter months, but not on all fires. BAER (burned area emergency response) teams do that, taking into account the potential for soil errosion, flooding, regrowth, etc. It's not really possible to simply re-seed all burn areas and be done with it, and in many cases soil sterilization and environmental damage is so great that regrowth doesn't occur for a long time.

Water is dropped. Primarily by helicopters and "scoopers" such as the CL415, it's used for expediency in some cases, and in others, because retardant can't be used in sensitive areas, adjacent to waterways or drainages, etc. In some areas, it's used because it's immediately available. One of the flexible functions of SEATs is that they can show up where there's no taner base and quickly go to work. I've done it from fire trucks and hydrants. Often when water is dropped, it's mixed with a surfactant, soap, or gel to modify the water behavior, or dropped as a foam. Water has a very short life on the fire, doesn't penetrate as well, isn't as heavy, drifts more, evaporates more before it hits the ground, and in general, tends to be the least effective, and can only be used direct on the fire, which makes it far less versatile or useful for most operations.

Guess the guys up at FNL lied to me about seeds being in the mix. It does sound like some contains fertilizer though.........

quote:

Originally posted by coloradohunter44:
Guess the guys up at FNL lied to me about seeds being in the mix. It does sound like some contains fertilizer though.........

Retardants are loaded with phosphates which are effective fertilizers- you’re right about that.

There are no seeds in the mix. There never have been.

There are phosphates and other chemicals which have the added benefit after the fire is over, of aiding in fertilizing the soil.

This isn't the reason retardant is dropped, and the reality is that you won't see strips of growth on old burns where retardant went, that show it's doing more to aid in plant growth than areas without.

The reason that it's even mentioned is to emphasize that it's not harmful. A few years ago the Sierra. Club had an injunction against retardant use, and it's commonly said in the industry that we're always just one drop away from having retardant use ended. Some of the extreme environmentalists are deadset against it, and the benefits of retardant are emphasized.

Retardant had minute traces of cyanide in it, which is inconsequential on land drops, but can't be had within 300' of a waterway. It doesn't take much in parts per million to kill fish. That's not as true today; retardant formulation isn't what it was ten years ago; it's much more environmentally friendly. However, drop some in a river or lake, and heads roll. It's a very, very big deal.

We got a little in Crater Lake 20+ years ago; we did an emergency jettison in a C-130 going down hill and it trailed across a highway and some of the retardant ended up in the water. We were immediately benched, investigators flown in. Unpleasant. Nobody asked if we were okay. We came back with brush in the wingtip.

The retardant color is there to make it visible for the air attack, and for other tankers to target their loads to overlap, so it's clear where the retardant went, to gauge drift, coverage, etc, and make adjustments as the fire goes on.

It does have a residual benefit, but I've never seen additional growth as a result later on.

Pretty freakin' cool. I watched a video with some jet-powered plane basically scooping up water on the move....that's gotta be hairy.

Pretty much what sn3guppy said. I have flown Bell 205 and 212 helicopters on a lot of fires, not only to drop water with bambi buckets but also to haul firefighters and supplies in and out.

I also bought an Air Tractor 802A single engine air tanker new, $1.2 million and my wife had a fit. Flew it on some fires and was very effective when paired with a medium helicopter. Fires are very expensive.

 
During the Yarnell Hill fire of 2013, there were two of the heavy tankers working. We have a view of Yarnell Hill from our living room, and it was amazing to watch them, plus many smaller tankers and heliocopters at work. Much of the refueling was at Wickenburg Airport (E25) which is just behind us, so they flew close to our house when refueling. That was a huge, nasty wildland fire, which resulted in the deaths of 19 Granite Mountain Hotshots, down from Prescott to assist the fight. Those 19 are still remembered in this area with memorials all over.

At Yarnell, numerous heavy tankers were flying, as well as the VLAT DC-10, Several SEATs flew, and a number of Type 1, II, and III helicopters. The airspace was thoroughly saturated with aircraft.

I was the first on scene there, and the last one to drop at Yarnell. I worked directly with the Granites. I was on the fire when the blow-up occurred and when the fatalities happened. I flew through the burn site early the next day enroute to Peeples Valley to do structure support, and have a very clear image in my mind of the first time I saw the burnover site after the blow-up. The next day was a stark contrast to a low exit I did on a drop, passing through Yarnell; everything was intact when I made that low pass, and then everything was black.

I remember very clearly getting up that next morning, early and passing through a hotel lobby, being surrounded by evacuees from the fire, all angry, demanding that I save their homes, yelling that I wasn't doing enough for them, venting anger. I understood their frustration, but when I stopped turned, and asked "what more do you want us to do? We're dying up there?" Nobody had much to say.

I’ve seen videos of an air tanker in nor Cal and so Cal that is a high wing, high-tail 4-engine jet with swept wings and a thick fuselage, similar to a C-141 or C-17 but I doubt it’s either. Can anyone tell me what this aircraft is? Not listed on Wikipedia’s page of aircraft for fire suppression.

BAE-146.

Also the RJ-85.

The BAE-146 designations are tanked internally, and the RJ-85 has the tank external to the fuselage (looks swollen).

Here’s cool video about crushing vehicles with aerial retardant.

Thanks, Guppy! So the RJ-85 looks like a pregnant cat, that’s probably what I saw.

And Radius, thanks for posting that great video!