LAA -- LOW FREQUENCY
LAA- (See LOCAL AIRPORT ADVISORY.)
LAAS- (See LOW ALTITUDE ALERT SYSTEM.)
LAHSO- An acronym for "Land and Hold Short Operation." These operations
include landing and holding short of an intersecting runway, a taxiway, a
predetermined point, or an approach/departure flightpath.
LAHSO-DRY- Land and hold short operations on runways that are dry.
LAHSO-WET- Land and hold short operations on runways that are wet (but not
contaminated).
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.
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.
(See ICAO term LANDING AREA.)
LANDING AREA [ICAO]- That part of a
movement area intended for the landing or takeoff of aircraft.
LANDING DIRECTION INDICATOR- A device which visually indicates the direction
in which landings and takeoffs should be made.
LANDING DISTANCE AVAILABLE [ICAO]- The length of
runway which is declared available and suitable for the ground run of an
aeroplane landing.
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 FAR 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.
(See STRAIGHT-IN LANDING.)
(See CIRCLE-TO-LAND MANEUVER.)
(See MINIMUM DESCENT ALTITUDE.)
(See INSTRUMENT APPROACH PROCEDURE.)
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.
LAST ASSIGNED ALTITUDE- The last
altitude/flight level assigned by ATC and acknowledged by the pilot.
LATERAL SEPARATION- The lateral spacing of
aircraft at the same altitude by requiring operation on different routes or in
different geographical locations.
LDA- (See LOCALIZER TYPE DIRECTIONAL AID.)
LDA [ICAO]- (See ICAO Term LANDING DISTANCE AVAILABLE.)
LF- (See LOW FREQUENCY.)
LIGHTED AIRPORT- An airport where runway and obstruction lighting is
available.
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.
LOCALIZER- The component of an ILS which provides
course guidance to the runway.
(See INSTRUMENT LANDING SYSTEM.)
(See ICAO term LOCALIZER COURSE.)
LOCALIZER COURSE [ICAO]- The
locus of points, in any given horizontal plane, at which the DDM (difference in
depth of modulation) is zero.
LOCALIZER OFFSET- An angular offset of the localizer from the runway extended
centerline in a direction away from the no transgression zone (NTZ) that
increases the normal operating zone (NOZ) width. An offset requires a 50 foot
increase in DH and is not authorized for CAT II and CAT III approaches.
LOCALIZER TYPE DIRECTIONAL AID- A NAVAID used for nonprecision instrument
approaches with utility and accuracy comparable to a localizer but which is not
a part of a complete ILS and is not aligned with the runway.
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.
LOCAL AIRPORT ADVISORY [LAA]- A service provided by
flight service stations or the military at airports not serviced by an operating
control tower. This service consists of providing information to arriving and
departing aircraft concerning wind direction and speed, favored runway,
altimeter setting, pertinent known traffic, pertinent known field conditions,
airport taxi routes and traffic patterns, and authorized instrument approach
procedures. This information is advisory in nature and does not constitute an
ATC clearance.
(See AIRPORT ADVISORY AREA.)
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.
LOCATOR [ICAO]- An LM/MF NDB used as an aid
to final approach.
Note: A locator usually has an average radius of rated coverage of between
18.5 and 46.3 km (10 and 25 NM).
LONGITUDINAL SEPARATION- The longitudinal spacing of aircraft at the same
altitude by a minimum distance expressed in units of time or miles.
LONG RANGE NAVIGATION- (See LORAN.)
LORAN- 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.
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 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 ALTITUDE ALERT, CHECK YOUR ALTITUDE
IMMEDIATELY-
(See SAFETY ALERT.)
LOW ALTITUDE ALERT SYSTEM- An automated function of the TPX-42 that alerts
the controller when a Mode C transponder - equipped aircraft on an IFR flight
plan is below a predetermined minimum safe altitude. If requested by the pilot,
LAAS monitoring is also available to VFR Mode C transponder - equipped aircraft.
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.