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.

In hazard reduction, burning narrow strips of fuel and leaving the rest of the area untreated by fire.

The technical and scientific specifications for management activities or potential actions mandated by the agency administrator and defined in land/resource management plans. Management requirements are derived from land/resource management plan and fire management plan standards and guidelines information. 

The dropping of fire retardants or suppressants from specially designed buckets slung below a helicopter.

Actual vehicle weight, including chassis, body, cab, equipment, water, fuel, crew, and all other load.