An event in which a fire moves through a location or overtakes personnel or equipment where there is no opportunity to utilize escape routes and safety zones, often resulting in personal injury or equipment damage.

The ICS title for individuals responsible for the management of functional sections: Operations, Planning, Logistics, and Finance/Administration.

Precipitation falling out of a cloud but evaporating before reaching the ground.

Area of fuel covered and degree of coverage on the fuel by a fire retardant, usually expressed in terms of gallons per hundred square feet (liters per square meter).

A geographic area of relatively homogenous climate, fuels and topography, tens of thousands of acres in size, within which the fire danger can be assumed to be uniform. The basic on-the-ground unit for which unique fire management decisions are made based on fire danger ratings. Weather is represented by one or more NFDRS weather stations. 

Any agency having jurisdictional responsibility for all or part of an incident.

An axle that supports a portion of the vehicle weight and transmits a driving force to the wheels.

The general plan or direction selected to accomplish incident objectives.

Species of vegetation that establish on a burned (or otherwise denuded) site from seed.

Term used in calculating from performance charts the permissible helicopter payload at which a helicopter is capable of hovering in ground effect or hovering out of ground effect, based on pressure altitude and air temperature.