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LARGE AIRCRAFT - Aircraft of more than 12,500 pounds. Maximum certificated takeoff weight.

LAT - Latitude.

LATERAL - Related to latitude; across an aircraft left to right.

LATERAL AXIX - The axis about which an aircraft pitches, extending out along each wing.

LATERAL CONTROL - The ability to make an airplane roll, or turn around its long axis, according to its pilot`s wishes.

LATERAL STABILITY - Stability about an airplane`s longitudinal (nose to tail) axis.

LATITUDE - Position on earth, north or south of the equator.

LEADING AND TRAILING EDGES - The foremost and rearmost edges of a wing.

LEADING EDGE - The very front edge of the wing or stabilizer. This is the edge that hits the air first.

LEAN - Refers to carburetor setting. When an engine is run too lean it will overheat, causing damage, and likely an in flight engine failure. Tuning a carburetor is best accomplished by starting rich, and working gradually to the condition which produces maximum power, while allowing a small amount of unburned fuel mixture to lubricate and cool the engine.

LEAN RUN - This happens when an engine develops a lean condition. Possible causes are improper tuning, improper fuel choice, fuel foaming due to excessive vibration, or a leak developing in the fuel delivery system. The air in the fuel line will cause the engine to run lean.

LED - Light-emitting diode.

LEG - A segment of a flight plan; flight path between two waypoints

LF ADF - Low Frequency Automatic Direction Finding

LFR - low-frequency radio range.

LIFT - The force exerted on the top of a moving airfoil as a low-pressure that causes a wing form to rise, perpendicular to the direction of motion.

LIFT-DRAG RATIO - The lift coefficient of a wing divided by the drag coefficient, as a primary measure of the efficiency of an aircraft.

LIGHTER-THAN-AIR AIRCRAFT - aircraft that can rise and remain suspended by using contained gas weighing less than the air that is displaced by the gas.

LIGHT-SPORT AIRCRAFT - An aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following:

LIRL - Low Intensity Runway Lights.

LLWAS - Low Level Wind Shear Alert System.

LLZ - Localizer (approach system).

LMB - Light marker beacon.

LMM - compass locator at middle marker.

LNAV - Lateral navigation guidance.

LOAD FACTOR - The ratio of a specified load to the total weight of the aircraft. The specified load is expressed in terms of any of the following: aerodynamic forces, inertia forces, or ground or water reactions.

LOADING (wing loading) - The load placed on the airfoil of a flying machine. In the case of an aircraft, this would be wing loading. Typically found by dividing the weight of the aircraft by the total area of the main wing (s). Note that wing loading is only a good comparison between aircrafts of the same size. Larger aircrafts appear to have a far higher wing loading while displaying similar flight characteristics.

LOC - Localizer receiver and indicator.

LOCALIZOR (LOC) - Part of ILS that provides lateral deviations from a preset course.

LOGBOOK - A pilot`s record of his flying achievements, including flight time, takeoffs, landings, and maneuvers mastered.

LOM - compass locator at outer marker.

LONGITUDE - Position on earth, east or west of the prime meridian.

LONGITUDINAL - Related to longitude; lengthwise along the center line of an aircraft forward.

LONGITUDINAL AXIS - The axis, about which an aircraft rolls, extends from nose to tail.