How the US Forest Service Fights Forest Fire – Aviation

helicopter and bucket

helicopter and bucket

One of the most important tools used by the Forest Service when they are fighting forest fires is aircraft, and they are used in several ways. Aircraft can greatly decrease the amount of time that it takes to contain a wildfire and it can even help identify spot fires before they are even mapped. To understand and appreciate the effort that is put into suppressing a forest fire, it is worthwhile to know how aviation is used.



Different Kinds of Aircraft

Both fixed wing aircraft (airplanes) and helicopters are used to fight forest fire. Smaller planes can be used as spotters, to find flare-ups that are well away from the main fire. This is important because the top of a tall tree can explode while it is burning. The gasses inside the tree often expand faster than their ability to escape out of the tree and the resulting explosion can send burning embers hundreds of yards in all directions. If the forest conditions are dry, which they commonly are if there is a forest fire, the burning embers can start spot fires. If these are noticed early on, they can be controlled before they can spread. Additionally, if the fire was caused by lightning, there is always the chance that other lightning strikes started other fires that haven’t yet been noticed.

The small airplanes have a vantage point of being able to see a lot of ground from above, so they can see a tendril of smoke before anyone on the ground is aware that there is a spot fire. The pilot can then radio in the location of the spot fire and personnel can be immediately dispatched to control the spot fire. This is the reason there is often a small, single engine plane circling a fire at a few hundred to a couple of thousand feet above the ground.

forest fire aircraft

Air Force Reserve aircrews and maintainers stand ready to fight wildfires using C-130 Hercules equipped with modular airborne firefighting systems, similar to this one. The aircraft can drop up to 3000 gallons of retardant covering an area one-quarter of a mile long and 60 feet wide. (File photo) U.S. Air Force photo by Staff Sgt. Daryl McKamey Public domain

Larger aircraft are also used. For instance, cargo planes can be fitted to allow them to carry fire retardant or water that can be dumped on the fire. The retardant functions by cutting off the air supply to the fire, smothering it and often giving ground crews a chance to knock it down before it flares up again. Some cargo planes are even fitted with a belly scoop that can be lowered to allow the airplane to fly over a water source, scooping the water up into the holding tank. The scoop is then closed and the plane can fly to the fire, where it can release the water.

As useful as belly bombers are, there can be a problem. Because of the heat that is generated by the fire, the air immediately above the fire usually rises rapidly. While the large aircraft can often deal with the updrafts, the updrafts drop the accuracy of the water or retardant drops. If the situation is compounded by steep and rugged terrain, a water or retardant drop can miss the target entirely, blown away by the winds. 

Helicopters go a long way toward solving this issue. A helicopter is fitted with a large bucket on a cable that can be raised or lowered. The helicopter can fly to a water source, lower the bucket to scoop up water and then fly back to drop it on the fire. Since the helicopter is able to hover in place, the water drop can be substantially more accurate. The downside is that a helicopter and bucket can’t carry as much water as a large cargo aircraft. Yet, they can make numerous trips to the water and to the fire in the time it takes the large fixed wing aircraft to make one.

With especially bad fires, large helicopters can be employed. An example is a helicopter known as a Skycrane. This large helicopter can carry substantially more water or retardant than smaller helicopters can. They are also quite a bit more expensive to fly, so there is a trade-off. In fact, helicopters can also function as spotters, but even a small helicopter tends to go through quite a bit more fuel than a single engine airplane, once the plane is in the air.

Men and Equipment Drops

Both airplanes and helicopters are also used to drop equipment, food and supplies and even men. Helicopters are more accurate, allowing everything to be deployed in a specific place, but large planes can carry more cargo, so there is again a trade-off. Helicopters are also capable of landing in a much smaller area, which is exceptionally handy for moving personnel or equipment from one location to another or for airlifting someone who is injured. Sadly and even though major injuries aren’t common, they do occur and having the means to transport an injured person so they can get medical attention is quite important.

Extreme Measures: Fighter Jets

It is very rare, but there have been times when military aircraft have also been used to fight large blazes. A fighter can deliver an incendiary that focuses the blast in a specific direction. This is usually used to create an emergency back-fire, destroying the fuel in front of an advancing fire. Because of the danger, this is rarely done unless extreme measures must be taken, usually to prevent the loss of life.

Coordination

The flying of the aircraft is naturally done by highly skilled pilots. They will be dealing with aircraft that are occasionally hard to control because of conditions and most of the pilots have extensive training for the work. However, everything is coordinated from the ground. The coordinator has access to the fire maps and they know exactly what needs to go where. They can also function as an air traffic controller, to lessen the chance of aircraft collisions. The position of coordinator is exceptionally important for the safety of the firefighters and pilots, as well as for the most rapid control of a fire.

Unmanned Aircraft

The use of drones should be mentioned at least in passing. The Forest Service can and does use drones on occasion, however this isn’t common when a major fire is actively being fought, because drones increase the chances of air collisions. In fact, the Forest Service often cautions that private drones should not be flown in the vicinity of a fire and have standing orders that if a drone is seen, all aircraft for the fire are to be grounded until the drone is removed from the area.



The use of aircraft to battle a forest fire is of exceptional importance, particularly in terrain that makes it hard to get to the fire on the ground. Understanding the role played by aircraft in fire suppression efforts is part of the ongoing series of articles aimed at people becoming more appreciative and aware of what goes into containing major wildfires. 






  • Comments

    1. Profile photo of Jean B Figues
      Jean B Figues

      It scares me thinking about these. In the Philippines forest fires are not really that serious.however, one rare case was when mountain climbers left fire at one of the mountains and it caused a huge fire where there was a need for a helicopter to drop ice and water into the fire

      1. Profile photo of Rex Trulove
        Rex Trulove Post author

        The Philippines is tropical, a lot moister and it gets a substantial amount of rain in comparison to this area. We have a lot of pine trees and fir trees that grow quite tall. Both of these burn very hot when the conditions are dry, as they are now. Last year, there was a very large fire north of here that covered 30,000 acres…about 120 square kilometers.

    2. Profile photo of Gil Camporazo
      Gil Camporazo

      A forest fire is not common in our country for most of our mountains are denuded. Anyway, what reminds me of fire is the sugarcane plantation across our school, is razed by fire. One of our students played with a firecracker and the lighted firecracker that went straight to the sugarcane field after it burst.

      It’s good the city’s fire truck after a call received responded right away> However, the firemen took so much time to put out the fire. I talked to the head of the community and suggested to him to cut those canes which the fire is coming and clean the nearby area where the fire is eating the canes. But it fell to a deaf ear. Anyway, the fire is under control half an hour.

      1. Profile photo of Rex Trulove
        Rex Trulove Post author

        I’ve heard of the same thing happening in Hawaii. In a way, that is similar to what happens in Eastern Montana. While the west side, the part I live in, is covered with trees, the east side is covered by prairie. Prairie grasses often grow taller than a man’s height and when a fire happens there, it is extremely hot and moves very fast. Houses, power lines and things like that are sometimes threatened, and the fire burns so hot it can easily set a house on fire, but the fires are different in that they burn up all the available fuel quickly. Those fires are usually allowed to burn, while protecting homes, farms, power lines, telephone lines and so forth. Unlike in the forests here, the grass fires will usually burn themselves out within a day to a few days, while a forest fire can smolder for months.

      1. Profile photo of Rex Trulove
        Rex Trulove Post author

        One of the first considerations the fire coordinators have is if there is a supply of water nearby that can be used. If there is, firefighting is a lot easier. In some places, there isn’t any water, though. Helicopters either have to fly a lot farther to get water or fill their buckets with fire retardant. Thankfully, Montana is blessed with a lot of rivers, lakes and ponds, and there are quite a few reservoirs.

        Incidentally, though the fire near here hasn’t grown much, according to the Forest Service, it is still nowhere near being contained. The next few days, we are supposed to have afternoon and evening thunderstorms. That should mean a drop in the temperature and an increase in humidity, which helps the firefighters. The downside is that it also means periodically gusty wind and the potential for more fires caused by lightning strikes…the leading cause of wildfire in the west.

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