## J 

Jet route.  A route designated to serve flight operations from 18,000 feet MSL up to and including FL 450. 

Jet stream.  A high-velocity narrow stream of winds, usually found near the upper limit of the troposphere, which flows generally from west to east. 

Judgment. The mental process of recognizing and analyzing all pertinent information in a particular situation, a rational evaluation of alternative actions in response to it, and a timely decision on which action to take. 

## K 

KIAS.  Knots indicated airspeed. 

Knot. The knot is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. 

Kollsman window.  A barometric scale window of a sensitive altimeter used to adjust the altitude for the altimeter setting. 

## L 

LAAS.  See local area augmentation system. 

Lag. The delay that occurs before an instrument needle attains a stable indication. 

Land breeze. A coastal breeze flowing from land to sea caused by temperature differences when the sea surface is warmer than the adjacent land. The land breeze usually occurs at night and alternates with the sea breeze that blows in the opposite direction by day. 

Land as soon as possible.  Land without delay at the nearest suitable area, such as an open field, at which a safe approach and landing is assured. 

Land as soon as practical.  The landing site and duration of flight are at the discretion of the pilot. Extended flight beyond the nearest approved landing area is not recommended. 

Land immediately. The urgency of the landing is paramount. The primary consideration is to ensure the survival of the occupants. Landing in trees, water, or other unsafe areas should be considered only as a last resort. 

Lateral axis. An imaginary line passing through the center of gravity of an airplane and extending across the airplane from wingtip to wingtip. 

Lateral stability (rolling). The stability about the longitudinal axis of an aircraft. Rolling stability or the ability of an airplane to return to level flight due to a disturbance that causes one of the wings to drop. 

Latitude. Measurement north or south of the equator in degrees, minutes, and seconds. Lines of latitude are also referred to as parallels. 

LDA.  See localizer-type directional aid. 

Lead radial.  The radial at which the turn from the DME arc to the inbound course is started. 

Leading edge. The part of an airfoil that meets the airflow first. 

Leading edge devices. High lift devices which are found on the leading edge of the airfoil. The most common types are fixed slots, movable slats, and leading edge flaps. 

Leading-edge flap. A portion of the leading edge of an airplane wing that folds downward to increase the camber, lift, and drag of the wing. The leading-edge flaps are extended for takeoffs and landings to increase the amount of aerodynamic lift that is produced at any given airspeed. 

Leans, the.  A physical sensation caused by an abrupt correction of a banked attitude entered too slowly to stimulate the motion sensing system in the inner ear. The abrupt correction can create the illusion of banking in the opposite direction. 

Licensed empty weight. The empty weight that consists of the airframe, engine(s), unusable fuel, and undrainable oil plus standard and optional equipment as specified in the equipment list. Some manufacturers used this term prior to GAMA standardization. 

Lift. A component of the total aerodynamic force on an airfoil and acts perpendicular to the relative wind. 

Limit load factor. Amount of stress, or load factor, that an aircraft can withstand before structural damage or failure occurs. 

Lines of flux.  Invisible lines of magnetic force passing between the poles of a magnet. 

L/MF. See low or medium frequency. 

LMM.  See locator middle marker. 

