Aerial firefighting is the use of aircraft and other aerial resources to combat wildfires. The types of aircraft used include fixed-wing aircraft and helicopters. Smokejumpers and rappellers are also classified as aerial firefighters, delivered to the fire by parachute from a variety of fixed-wing aircraft, or rappelling from helicopters. Chemicals used to fight fires may include water, water enhancers such as foams and gels, and specially formulated fire retardants.
A wide variety of terminology has been used in the popular media for the aircraft (and methods) used in aerial firefighting. The terms airtanker or air tanker generally refer to fixed-wing aircraft based in the United States; "airtanker" is used in official documentation. The term "waterbomber" is used in some Canadian government documents for the same class of vehicles, though it sometimes has a connotation of amphibians.
Air attack is an industry term used for the actual application of aerial resources, both fixed-wing and rotorcraft, on a fire. Within the industry, though, "air attack" may also refer to the supervisor in the air (usually in a fixed-wing aircraft) who supervises the process of attacking the wildfire from the air, including fixed-wing airtankers, helicopters, and any other aviation resources assigned to the fire. The Air Tactical Group Supervisor (ATGS), often called "air attack," is usually flying at an altitude above other resources assigned to the fire, often in a fixed-wing plane but occasionally (depending on assigned resources or the availability of qualified personnel) in a helicopter.
Depending on the size, location, and assessed potential of the wildfire, the "air attack" or ATGS person may be charged with initial attack (the first response of firefighting assets on fire suppression), or with extended attack, the ongoing response to and management of a major wildfire requiring additional resources including engines, ground crews, and other aviation personnel and aircraft needed to control the fire and establish control lines or firelines ahead of the wildfire.
A wide variety of helicopters and fixed-wing aircraft are used for aerial firefighting. In 2003, it was reported that "The U.S. Forest Service and Bureau of Land Management own, lease, or contract for nearly 1,000 aircraft each fire season, with annual expenditures in excess of US$250 million in recent years".