Firefighting aircraft

Aircraft, both planes and helicopters, modified to carry and release water or other flame-retardant liquids for the extinguishing of large fires, usually in remote areas.


The first use of an airplane to combat a wildland fire occurred in California during 1919. Modifications to private aircraft continued for several decades but remained limited and experimental. In 1946, Glenn L. Martin, founder of the Martin Aircraft Company, designed an aircraft known as the Mars, which he initially envisioned as a long-range mission bomber with heavy lift capabilities. The four Mars planes, named the Marianas, Phillippine, Hawaii, and Caroline, transported troops and cargo between the islands of the South Pacific from 1946 to 1959. After setting world records for flight duration and airlift ability and logging more than eighty-seven thousand accident-free hours while in service with the U.S. Navy, the airplanes were retired. In 1959, after a series of catastrophic forest fires, a group of timber companies formed the Forest Industries Flying Tankers and purchased the four Mars planes, modifying them to serve as water bombers. In 1961, the Marianas crashed on a firefighting mission and in 1962 a hurricane destroyed the Caroline on land. The other two aircraft, the Phillippine and the Hawaii, were still in service at the beginning of the twenty-first century.

The Mars aircraft carries a crew of four, including the captain, first officer, and two flight engineers. Within ten minutes of receiving an emergency call, the planes are airborne and provide the initial attack on large fires, followed by repeated drops every fifteen minutes during sustained operations. Once the aircraft reaches the water source, the pilot begins the intake procedure by maintaining a constant speed of 60 to 70 knots while the scoops are turned to the down position. Water injected at the rate of 1 ton per second requires the flight engineer to continually advance the throttle to maintain the proper speed. When the tank is full the scoops are raised and the flight engineer takes off just as in a normal takeoff from land. Once the plane is back in flight, a foam concentrate is injected into the 7,200 gallons of water, where it remains inert until dropped. As the water falls, the tumbling action causes the foam to expand, transforming the water into a fire-retardant 4 percent solution. The aircraft, equipped with four Wright Cyclone R3350-24WA engines, measures 120 feet in length, has a 60,000-pound water/foam load limit, and can fly for over 5 hours before landing. When dropped from a height of 150 to 200 feet, the foam covers an area of 3 to 4 acres. Two additional aircraft assist the Mars planes in their firefighting efforts. The Grumman G21A Goose spots the fires and guides the Mars pilots into the bombing pattern. Responsible for coordinating efforts with the fire boss on the ground, the pilot of the Goose determines altitude and drop height and develops an exit plan. All of the pilots are trained on both the Mars and the Goose aircraft, enabling them to predict in-flight and drop requirements more accurately. Since 1974, Bell 206L-1 LongRange helicopters have also been used for smaller fires caused by lightning strikes. Each helicopter is equipped with a Bambi Bucket with a capacity of 140 gallons. The helicopters are also used to evacuate people and provide tactical support. While the Forest Industries Flying Tankers concentrate on large fires located on property owned by Weyerhaeuser Company Limited and TimberWest Forest Limited, the two lumber companies that own Forest Industries, they also contract out their services on occasion.

Private Aerial Firefighting Companies

Since the early 1960’s, a number of other companies have offered similar services using a variety of aircraft developed for firefighting missions. Based primarily in heavily forested areas, the firefighting enterprises include several multiengine airtanker companies. Aero Flite, of Kingman, Arizona, was founded in 1963 and operates one C-54E, one C-54G, one M-18B Dromader, one Aztec, and one Piper Cherokee 6 within the continental United States and Alaska. Aero Union Corporation of Chico, California, the largest contractor of firefighting services in the United States, manufactures aerial firefighting aircraft and systems with a patented constant flow drop system used on Lockheed C-130’s, Lockheed L-188’s, and P3’s, as well as on the Lockheed P-2V aircraft. The company also provides aircraft and personnel for firefighting missions in cooperation with the U.S. Department of Agriculture and numerous other federal agencies. Aero operates a fleet of six P3’s, four SP-2H’s, and two C-64’s and contracts for services in California, Idaho, Oregon, Arizona, and Utah. The company manufactures retardant aerial delivery systems (RADS), helicopter-borne aerial firefighting systems, auxiliary fuel systems, aerial spray systems, aerial refueling tanks, modular airborne firefighting systems, bulk fuel transport tanks, 1080 refueling store systems, and automated cargo handling systems.

ARDCO of Tucson, Arizona, formed in 1976, has a fleet of three DC-4’s and covers areas in Nevada, Oregon, and California, providing firefighting services for the U.S. Department of Agriculture and the Forest Service. Butler Aircraft Company of Redmond, Oregon, founded in 1946, introduced the B-17 into aerial firefighting and also uses two DC-7’s, one DC-6, and one C-130 in its fleet providing services for the U.S. Department of Agriculture and Forest Service in Washington, Oregon, Arkansas, Tennessee, Alaska, Michigan, and Minnesota. Hawkins & Powers Aviation, out of Greybull, Wyoming, has specialized in aerial firefighting and agricultural spraying since 1958. Its fleet includes five PB-4Y-2’s, fourteen P-2V’s, seven C-130A’s, six C-97’s, and one P2-T, as well as a fleet of heli-tankers that includes two Bell UH-2B’s, two Bell 206L3’s, two Bell 206 BIII’s, two Hughes 500D’s, and two Hiller 12E’s. The company provides services in Alaska, Australia, Washington, Oregon, Minnesota, Idaho, Nevada, Colorado, New Mexico, Arizona, Montana, Utah, Tennessee, North Carolina, Florida, Pennsylvania, New York, California, Oklahoma, Texas, and South Dakota.

Hirth Air Tankers of Buffalo, Wyoming, was formed in 1987 and operates two PV-2 airtankers, two PV-2 sprayers, and one Grumman American G164B-600 Ag-Cat single-engine airtanker. Neptune, of Missoula, Montana, was founded in 1993 and operates nine Lockheed P2-V Neptunes throughout the United States. International Air Response of Chandler, Arizona, founded in 1965, operates three C-130’s, one DC-7 airtanker, and two DC-7 sprayers throughout the continental United States, Alaska, Spain, and France. T.B.M., of Tulare, California, founded in June, 1957, has provided aerial firefighting services since 1959. Its fleet includes two C-130’s, one C-54, one DC-6, one DC-7, and one SP-2H leased from Aero Union.

The two major companies that provide heli-tanker contract services are Erickson Air-Crane Company of Central Point, Oregon, and Heavy Lift Helicopters of Clovis, California. Single-engine airtanker companies such as Downstown Aero of Vineland, New Jersey, and Queen Bee Air Specialties of Rigby, Idaho, also provide services on a contractual basis.

Many of these companies use vintage World War II aircraft modified with retardant aerial delivery systems (RADS). One of the most common systems is used on the Lockheed P-3 Orion and L-188 Electra aircraft. Manufactured by Aero Union Corporation, the RADS II system is a constant-flow belly tank using a computer-controlled door system that allows the crew to select the appropriate flow rate. Equipped with a 3,000-gallon tank, the computerized system maintains a constant flow with a uniform drop rate with no overlapping or gaps. Used for initial attacks on grasslands or heavy timber fires, the advanced system prevents possible fire burn-through.

One of the more common heli-tankers is the S-70A/UH-60L Firehawk. The Firehawk has a one-thousand-gallon water tank, a 30-gallon foam tank, a 1,000-gallon-per-minute snorkel, and computer-controlled doors. The snorkel allows the heli-tanker to fill the water tank in one minute. The most recent addition to the fleet of heli-tankers is the S-64 Skycrane Fire Fighting Tank, with its 2,000-gallon water tank and 60-gallon foam tank. The Skycrane’s snorkel is also capable of filling the water tank in one minute, even though its capacity is double that of the Firehawk.

Military Firefighting

Although several private companies across the country provide firefighting services, sometimes the U.S. military is called upon to assist when resources are limited and the extent of the fire warrants additional aircraft. Instead of building planes specifically for firefighting missions, the military transforms the Lockheed C-130 Hercules cargo planes into firefighting aircraft by adding systems such as the Modular Airborne Fire Fighting System (MAFFS).

Installation of the MAFFS system can be completed within one hour and contains a 3,000-gallon tank that can be filled in fifteen minutes and fully discharged in five seconds. Releasing the retardant alternately from a series of tanks, the MAFFS system allows pilots to maintain complete control over the aircraft during the drop, as opposed to other systems that require in-flight compensation as the nose of the aircraft pulls up and gravity pulls the retardant out of the rear of the plane. Installation of the MAFFS system is a two-step process. The initial installation of the lower tank is permanent and adds approximately 500 pounds to the aircraft. The upper tank attaches to the floor line and is removed after the firefighting mission is over, allowing the C-130 to be used once again for cargo and troop transport. The fire retardant released from the MAFFS system is a chemical called phos chek. In addition to reducing the combustion of plants and trees even after it loses its moisture, phos chek also contains a fertilizer that enhances regrowth of burned areas and helps prevent further soil erosion.

Mission and Operation

The mission of the firefighting aircraft is to extinguish forest and wildland fires in cooperation with federal, state, and local agencies. In the United States, the federal agencies responsible for wildfire firefighting are the Forest Service, the Bureau of Land Management, the National Park Service, the Bureau of Indian Affairs, and the Fish and Wildlife Service. Private airtanker companies work together with these agencies to control and manage fires. During the first six months of 1999, more than 1,097,400 acres of wildland had burned. Two of the worst fires occurred in Florida, where eight hundred firefighters fought the blaze for several weeks. When a wildland fire is reported, local crews respond first with an initial attack. This is usually provided by private companies, and 98 percent of fires are put out at this stage. If additional resources are required, one of the eleven nationwide coordinating centers are notified. Geographic area coordinating centers are located in Albuquerque, New Mexico; Riverside, California; Salt Lake City, Utah; Fairbanks, Alaska; Portland, Oregon; Broomfield, Colorado; Missoula, Montana; Milwaukee, Wisconsin; Reno, Nevada; Atlanta, Georgia; and Redding, California. The coordinating center then notifies the National Interagency Coordination Center in Boise, Idaho, where the National Wildfire Coordinating Group assumes control over the efforts. This group has extensive resources available nationwide, including 70 twenty-person Hotshot crews trained to handle complex firefighting situations; 409 individual smoke jumpers with 19 support aircraft for initial attacks in the western portion of the United States; 58 contract airtankers; a large transport for crew and equipment; 11 lead planes for tactical operations; 23 helicopters; 3 aircraft outfitted with infrared scanners capable of mapping the fires; 17 incident management teams trained specifically for handling complex situations; 447 twenty-person geographically located teams that can be called upon if necessary; 50 communication kits; 21 contractors that provide catering and shower facilities for the firefighting teams; and 11 warehouses full of firefighting equipment and supplies.


  • Fuller, Margaret. Forest Fires: An Introduction to Wildland Fire Behavior, Management, Firefighting, and Prevention. New York: John Wiley & Sons, 1991. Discusses wildland fires, their environmental impact, and several well-known wildfires, and provides detailed information on firefighting behavior, management, and operations, including the use of firefighting aircraft.
  • Lowe, Joseph, et al. Wildland Firefighting Practices. Albany, N.Y.: Delmar Thomson Learning, 2001. Describes the process of firefighting in wildland areas and provides illustrations to help the reader understand topics such as burn-through. The author, a firefighter himself, includes information on ground operations and the use of fixed-wing aircraft and helicopters.
  • Perry, Donald G. Wildland Firefighting: Fire Behavior, Tactics, and Command. Bellflower, Calif.: Fire Publications, 1990. A reference for the tactical operations involved in fighting large fires in remote areas. Focuses on the command structure but provides a good deal of information on the use of firefighting aircraft.


Bell Aircraft


Lockheed Martin

McDonnell Douglas


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