Nozzle tips used to change orifice size of a hose stream.

The mean solar times of sunset and sunrise as published in the Nautical Almanac, converted to local standard time for the locality concerned.

The midflame wind speed adjusted for the effect of slope on fire spread.

The set of responsibilities and ethical considerations that define the extent or limits of the care provider within the current standards of practice.

An aircraft mishap in which there is no intent to fly. However, the power plants and/or rotors are in operation and damage is incurred requiring replacement or repair of rotors, propellers, wheels, tires, wing tips, flaps, etc., or injury is incurred requiring first-aid or medical attention.

The heat energy resulting from the complete combustion of a fuel, expressed as the quantity of heat per unit weight of fuel. The high heat of combustion is the potential available, and the low heat of combustion is the high heat of combustion minus several losses that occur in an open system (primarily heat of vaporization of moisture in the fuel).

A condition of poor contaminant dispersion which may result in concentrations considered potentially harmful to health or welfare. Episodes may also occur during periods of fairly good dispersion if the source of air contaminants is extremely large.

An internal area of an aircraft specifically designed to carry baggage or cargo.

Resistance to wetting exhibited by some soils, also called water repellency. The phenomenon may occur naturally or may be fire-induced. It may be determined by water drop penetration time, equilibrium liquid-contact angles, solid-air surface tension indices, or the characterization of dynamic wetting angles during infiltration. 

A concave or cup-shaped char pattern found on the side of fuels exposed to the oncoming fire including small stumps (generally 10 inch diameter and less are more reliable), grass stem ends and terminal ends of brush and tree limbs (generally less than 1/2 inch diameter) that indicate the direction of fire progression at that point. One of the 11 NWCG categories of fire pattern indicators.