Aerial firefighting is the use of aviation assets, both fixed and rotary wing, to fight wildfires, directly and through the movement of firefighting personnel. Smokejumpers and rappellers are also classified as aerial firefighters, being delivered by parachute from a variety of fixed-wing aircraft, or rappelling from various helicopters. Agents used to fight fires may be either water or specially-formulated fire retardants. Aerial firefighting is almost always used in conjunction with ground-based efforts, as aircraft are only one weapon in the firefighting arsenal. However, there have been cases of aircraft extinguishing fires long before ground crews were able to reach them.
Terminology varies from agency to agency, but in the U.S. many of the overall operational procedures are governed by interagency guidelines and policies, and in these, aerial firefighting broadly encompasses three basic missions: