Aeronautical Terms beginning with L
L/MF
Low or Medium Frequency.
LAA
Local Airport Advisory
LAAS
Local Area Augmentation System
Lag
The delay that occurs before an instrument needle attains a stable indication.
LAHSO
Land and Hold Short Operations. Operations which include simultaneous takeoffs and landings and/or simultaneous landings when a landing aircraft is able and is instructed by the controller to hold short of the intersecting runway/taxiway or designated hold-short point. Pilots are expected to promptly inform the controller if the hold short clearance cannot be accepted.
Land And Hold Short Operations
Operations which include simultaneous takeoffs and landings and/or simultaneous landings when a landing aircraft is able and is instructed by the controller to hold-short of the intersecting runway/taxiway or designated hold-short point. Pilots are expected to promptly inform the controller if the hold short clearance cannot be accepted.
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.
Land-Based Air Defense Identification Zone
An ADIZ over U.S. metropolitan areas, which is activated and deactivated as needed, with dimensions, activation dates and other relevant information disseminated via NOTAM. Note: ADIZ locations and operating and flight plan requirements for civil aircraft operations are specified in 14 CFR Part 99.
Landing Area
Any locality either on land, water, or structures, including airports/heliports and intermediate landing fields, which is used, or intended to be used, for the landing and takeoff of aircraft whether or not facilities are provided for the shelter, servicing, or for receiving or discharging passengers or cargo.
Landing Direction Indicator
A device which visually indicates the direction in which landings and takeoffs should be made.
Landing Distance Available (LDA)
The runway length declared available and suitable for a landing airplane.
Landing Minimums
The minimum visibility prescribed for landing a civil aircraft while using an instrument approach procedure. The minimum applies with other limitations set forth in 14 CFR Part 91 with respect to the Minimum Descent Altitude (MDA) or Decision Height (DH) prescribed in the instrument approach procedures as follows: a. Straight-in landing minimums. A statement of MDA and visibility, or DH and visibility, required for a straight-in landing on a specified runway, or b. Circling minimums. A statement of MDA and visibility required for the circle-to-land maneuver. Note: Descent below the established MDA or DH is not authorized during an approach unless the aircraft is in a position from which a normal approach to the runway of intended landing can be made and adequate visual reference to required visual cues is maintained.
Landing Roll
The distance from the point of touchdown to the point where the aircraft can be brought to a stop or exit the runway.
Landing Sequence
The order in which aircraft are positioned for landing.
Large
An Aircraft Class Wake Turbulence Separation Minima. Aircraft of more than 41,000 pounds, maximum certificated takeoff weight, up to but not including 300,000 pounds.
Large Aircraft
An aircraft of more than 12,500 pounds, maximum certificated takeoff weight. As defined in 14 CFR part 1.
Lateral axis
An imaginary line passing through the center of gravity of an airplane and extending across the airplane from wingtip to wingtip.
Lateral Navigation (LNAV)
A function of area navigation (RNAV) equipment which calculates, displays, and provides lateral guidance to a profile or path.
Lateral Separation
The lateral spacing of aircraft at the same altitude by requiring operation on different routes or in different geographical locations.
Latitude
Measurement north or south of the equator in degrees, minutes, and seconds. Lines of latitude are also referred to as parallels.
Leading edge
The part of an airfoil that meets the airflow first.
LFR
Low-Frequency Radio Range.
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.
Lift-Off
The act of becoming airborne as a result of the wings lifting the airplane off the ground, or the pilot rotating the nose up, increasing the angle of attack to start a climb.
Light Gun
A handheld directional light signaling device which emits a brilliant narrow beam of white, green, or red light as selected by the tower controller. The color and type of light transmitted can be used to approve or disapprove anticipated pilot actions where radio communication is not available. The light gun is used for controlling traffic operating in the vicinity of the airport and on the airport movement area.
Light Icing
The rate of accumulation may create a problem if flight is prolonged in this environment (over 1 hour). Occasional use of deicing/anti-icing equipment removes/prevents accumulation. It does not present a problem if the deicing/anti-icing equipment is used.
Light-sport aircraft
An aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following:
(1) A maximum takeoff weight of not more than—
(i) 1,320 pounds (600 kilograms) for aircraft not intended for operation on water; or
(ii) 1,430 pounds (650 kilograms) for an aircraft intended for operation on water.
(2) A maximum airspeed in level flight with maximum continuous power (Vh) of not more than 120 knots CAS under standard atmospheric conditions at sea level.
(3) A maximum never-exceed speed (Vne) of not more than 120 knots CAS for a glider.
(4) A maximum stalling speed or minimum steady flight speed without the use of lift-enhancing devices (Vs1) of not more than 45 knots CAS at the aircraft’s maximum certificated takeoff weight and most critical center of gravity.
(5) A maximum seating capacity of no more than two persons, including the pilot.
(6) A single, reciprocating engine, if powered.
(7) A fixed or ground-adjustable propeller if a powered aircraft other than a powered glider.
(8) A fixed or feathering propeller system if a powered glider.
(9) A fixed-pitch, semi-rigid, teetering, two-blade rotor system, if a gyroplane.
(10) A non-pressurized cabin, if equipped with a cabin.
(11) Fixed landing gear, except for an aircraft intended for operation on water or a glider.
(12) Fixed or retractable landing gear, or a hull, for an aircraft intended for operation on water.
(13) Fixed or retractable landing gear for a glider.
Lighted Airport
An airport where runway and obstruction lighting is available.
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.
Line Up And Wait (LUAW)
Used by ATC to inform a pilot to taxi onto the departure runway to line up and wait. It is not authorization for takeoff. It is used when takeoff clearance cannot immediately be issued because of traffic or other reasons.
Lines of flux
Invisible lines of magnetic force passing between the poles of a magnet.
LIRL
Low Intensity Runway Lights
LO CIGS
Low Ceilings. Low clouds.
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, inertial forces, or ground or water reactions.
LOC
Localizer. The component of an ILS that provides course guidance to the runway.
Local Traffic
Aircraft operating in the traffic pattern or within sight of the tower, or aircraft known to be departing or arriving from flight in local practice areas, or aircraft executing practice instrument approaches at the airport.
Localizer (LOC)
The portion of an ILS that gives left/right guidance information down the centerline of the instrument runway for final approach.
Localizer Usable Distance
The maximum distance from the localizer transmitter at a specified altitude, as verified by flight inspection, at which reliable course information is continuously received.
Long Range Navigation
LORAN. [Decommissioned in 2010]
Long range navigation (LORAN)
[Decommissioned in 2010] An electronic navigational system by which hyperbolic lines of position are determined by measuring the difference in the time of reception of synchronized pulse signals from two fixed transmitters. LORAN-A operates in the 1750–1950 kHz frequency band. LORAN-C and -D operate in the 100–110 kHz frequency band.
Long-range communication system (LRCS)
A system that uses satellite relay, data link, high frequency, or another approved communication system which extends beyond line of sight.
Long-range navigation system (LRNS)
An electronic navigation unit that is approved for use under instrument flight rules as a primary means of navigation, and has at least one source of navigational input, such as inertial navigation system, global positioning system, Omega/very low frequency, or Loran C.
Longitude
Measurement east or west of the Prime Meridian in degrees, minutes, and seconds. The Prime Meridian is 0° longitude and runs through Greenwich, England. Lines of longitude are also referred to as meridians.
Longitudinal Axis
An imaginary line through an aircraft from nose to tail, passing through its center of gravity. The longitudinal axis is also called the roll axis of the aircraft. Movement of the ailerons rotates an airplane about its longitudinal axis.
Longitudinal Stability (Pitching)
Stability about the lateral axis. A desirable characteristic of an airplane whereby it tends to return to its trimmed angle of attack after displacement.
LOP
Line-of-position
LORAN
Long Range Navigation System [Decommissioned in 2010]
Lost Communications
Loss of the ability to communicate by radio. Aircraft are sometimes referred to as NORDO (No Radio). Standard pilot procedures are specified in 14 CFR Part 91. Radar controllers issue procedures for pilots to follow in the event of lost communications during a radar approach when weather reports indicate that an aircraft will likely encounter IFR weather conditions during the approach.
Low Altitude Airway Structure
The network of airways serving aircraft operations up to but not including 18,000 feet MSL.
Low Approach
An approach over an airport or runway following an instrument approach or a VFR approach including the go-around maneuver where the pilot intentionally does not make contact with the runway.
Low Frequency
The frequency band between 30 and 300 kHz.
Low or medium frequency
A frequency range between 190 and 535 kHz with the medium frequency above 300 kHz. Generally associated with nondirectional beacons transmitting a continuous carrier with either a 400 or 1,020 Hz modulation.
LUAW
Line Up and Wait
Lubberline
The reference line used in a magnetic compass or heading indicator.
LZ
Landing Zone
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