Glossary of Fire Terms
  

Air Tanker

Fixed-wing aircraft certified by the FAA as being capable of transport and delivery of fire retardant.
 

Blowup

Sudden increase in fireline intensity or rate of spread of a fire sufficient to preclude direct control or to upset existing suppression plans.  Often accompanied by violent convection and may have other characteristics of a fire storm.
 

Closed Area

An area in which specified activities or entry are temporarily restricted to reduce risk of human caused fires.
 

Confine

A strategy employed whereby a fire perimeter is managed using a combination of direct and indirect actions.  It often includes the use of topographic features, fuel, and weather factors.
 

Containment

Completion of a control line around a wildland fire and any associated spot fires which can reasonably be expected to stop the fires spread.
 

Control

Completion of a control line around a wildland fire and any associated spot fires, burn out of any unburned area adjacent to the fire side of the control lines, and the cooling down of all hot spots that are immediate threats to the control line.  In addition, the line can reasonably be expected to hold under the foreseeable conditions.
 

Crew

An organized group of firefighters under the leadership of a crew boss or other designated official.
 

Crown Fire

A fire that advances from top to top of trees or shrubs more or less independent of a surface fire.  Crown fires are sometimes classed as running.
 

Direct Attack

Any treatment applied directly to burning fuel such as wetting, smothering, or chemically quenching the fire or by physically separating the burning from unburned fuel.
 

Drought

A period of relatively long duration with substantially below normal precipitation, usually occurring over a large area.
 

Extreme Fire Behavior

"Extreme" implies a level of fire behavior characteristics that ordinarily precludes methods of direct control action.  One or more of the following is usually involved: high rate of spread, prolific crowning and/or spotting, presence of fire whirls, strong convection column.  Such fires often exercise some degree of influence on their environment and behave erratically, sometimes dangerously. 
 

Firebrand

Any source of heat, natural or human made, capable of igniting wildland fuels.  Flaming or growing fuel particles that can be carried naturally by wind, convection currents, or by gravity into unburned fuels.
 

Fire Danger

The sum of constant danger and variable danger factors, affecting the inception, spread, resistance to control, and subsequent fire damage; often expressed as an index (i.e. Burning Index, Energy Release Component).
 

Fireline

The part of a control line (i.e. perimeter) that is scraped or dug down to the mineral soil layer to prevent fire spread.
 

Fire Front

The part of a fire in which continuous combustion is taking place.  Unless otherwise specified, the fire front is assumed to be the leading edge of the fire perimeter.
 

Fire Retardant

Any substance except plain water that by chemical or physical action reduces flammability of fuels or slows their rate of combustion.
 

Fire Use

The combination of wildland fire use and prescribed fire application to meet resource objectives.

Fire Weather

Weather conditions which influence fire ignition, behavior, or suppression.
 

Flame Length

The distance between the flame tip and the midpoint of the flame depth at the base of the flame.  A good indicator of fire intensity. 
 

Flash Fuels

Fuels such as grass, leaves, draped pine needles, fern, tree moss, and some kinds of slash.  Flash fuels can readily ignite and can be consumed rapidly when dry.
 

Fuel Condition

Relative flammability of fuel as determined by fuel type and environmental conditions.
 

Gridding

To search for a small fire by systematically traveling over an area on parallel courses or gridlines.
 

Helitack

The use of helicopters to transport crews, equipment, and fire retardants or suppressants to the fireline during the initial stages of a fire.
 

Hotshot Crew

Intensively trained firefighting crew used primarily in handline construction.  Often referred to as a Type 1 crew.
 

Incident Commander

Individual responsible for the management of all incident operations at the incident site.
 

Incident Management Team

The Incident Commander and appropriate general and command staff personnel assigned to oversee management of an incident.  Lead positions include Incident Commander, Operations Chief, Plans Chief, Logistics Chief, Finance Chief, and Air Operations Chief.
 

Initial Attack

The actions taken by the first resources to arrive at a wildfire to protect lives and property, and prevent further extension of the fire.
 

Ladder Fuels

Fuels which provide vertical continuity, thereby allowing fire to carry from surface fuels into the crowns of trees or shrubs with relative ease.  They help initiate and assure the continuation of crowning.
 

Large Fire

For statistical purposes, a fire burning more than 100 acres in shrub, timber, and slash, and 300 acres in grass.
 

Mop-up

Extinguishing or removing burning material near control lines, including felling snags, and trenching logs to prevent rolling after an area has burned.
 

Nomex

Trade name for a fire resistant synthetic material used in the manufacturing of flight suits, and pants and shirts used by firefighters.  Aramid is the generic name.
 

Out

Completion of all activities related to control of a fire.  This includes elimination of all smoke, residual heat locations, and the potential for any future fire spread. 
 

Prescribed Fire

Any fire ignited by management actions to meet specific objectives.  A written, approved prescribed fire plan must exist, which includes meeting National Environment Protection Act (NEPA) requirements.
 

Rate of Spread

The relative activity of a fire in extending its horizontal dimensions.  It is expressed as rate of increase of the total perimeter of the fire, as rate of forward spread of the fire front, or as rate of increase in an area, depending the intended use of the information.
 

Retardant

A substance or chemical agent which reduces the flammability of combustibles.

Smoldering

A fire burning without flame and barely spreading.
 

Snag

A standing dead tree or part of a dead tree from which at least the leaves and smaller branches have fallen.
 

Spot Fire

Fire ignited outside the perimeter of the main fire.  Often spot fires start by flying firebrands.
 

Wildland Fire

Any non-structure fire, other than prescribed fire, that occurs in the wildland.
 

Wildland Fire Use

The management of a naturally ignited wildland fire to accomplish specific pre-stated resource management objectives in predefined geographic areas outlined in the units Fire Management Plan (FMP).  See also Fire Use.
 

Wildland/Urban Interface

The line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels.
 

Wind Shift

A change in the average wind direction by 45 degrees or more and takes less than 15 minutes to change.  Wind speed must be 6 knots or greater.