Tanks, doors, and release mechanism installed in aircraft for cascading fire retardants.

A circle graduated in 360 degrees in a clockwise direction from true (astronomic) north.

An airtanker is "on final" when it is on line with the target and intends to make the drop on that pass; also applies to cargo dropping.

An agency form used to calculate helicopter allowable payload.

Geographic subdivision of a fire-protected area, delimiting the initial attack bounds of a single fire guard or fire crew.

Effect of wind on smoke, retardant drops, paracargo, smokejumper streamers, etc.

The potential fire loss a community is willing to accept rather than provide resources to reduce such losses.

Distance equal to the wingspread of the airtanker being used; used for corrections right or left of the flight path.

A wildland fire whose activity is determined by the convection column.

In the 1978 version of NFDRS, the herbaceous stage when herbaceous fuel moisture falls to 30% or less.