Weak or missed area in a retardant drop or in a fireline.

In aviation, the intended direction of horizontal flight.

A fire that persists through the winter months until the beginning of fire season.

A chemical or mixture that may present an unreasonable risk of injury to health or the environment.

A tank, usually collapsible, used as a reservoir in the relay of water from one fire pump to another.

Technique of landing specifically trained and certified firefighters from hovering helicopters; involves sliding down ropes with the aid of friction-producing devices.

The study of the effects of fire on living organisms and their environment.

A turret-type nozzle usually mounted on an engine.

A person hired and compensated under the Pay Plan for Emergency Workers.

A person employed as an emergency worker on a forest or wildland fire which threatens damage to property under public management. Emergency firefighters are hired for the duration of the emergency only.