Pilot/Controller Glossary

Approaches (SOIA) to parallel runways whose
centerlines are separated by less than 3,000 feet and
at least 750 feet. NTZ monitoring is required to
conduct these approaches.
(See SIMULTANEOUS OFFSET INSTRUMENT
APPROACH (SOIA).)
(Refer to AIM)

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.
(Refer to AIM.)

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).

LONG RANGE NAVIGATION-
(See LORAN.)

LONGITUDINAL SEPARATION- The longitudinal spacing of aircraft at the same altitude by a
minimum distance expressed in units of time or
miles.
(See SEPARATION.)
(Refer to AIM.)

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. In 2010, the U.S. Coast
Guard terminated all U.S. LORAN-C transmissions.
(Refer to AIM.)

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.
(Refer to 14 CFR Part 91.)
(Refer to AIM.)

LOST LINK (LL)- An interruption or loss of the
control link, or when the pilot is unable to effect
control of the aircraft and, as a result, the UA will
perform a predictable or planned maneuver. Loss of
command and control link between the Control
Station and the aircraft. There are two types of links:
a. An uplink which transmits command instructions to the aircraft, and
b. A downlink which transmits the status of the
aircraft and provides situational awareness to the
pilot.
LOST LINK PROCEDURE- Preprogrammed or
predetermined mitigations to ensure the continued
safe operation of the UA in the event of a lost link
(LL). In the event positive link cannot be established,
flight termination must be implemented.
LOW ALTITUDE AIRWAY STRUCTURE- The
network of airways serving aircraft operations up to
but not including 18,000 feet MSL.
(See AIRWAY.)
(Refer to AIM.)

LOW ALTITUDE ALERT, CHECK YOUR ALTITUDE IMMEDIATELY-
(See SAFETY ALERT.)

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.
(Refer to AIM.)

LOW FREQUENCY (LF)- The frequency band
between 30 and 300 kHz.
(Refer to AIM.)

LOCALIZER PERFOMRNACE WITH VERTICAL GUIDANCE (LPV)- A type of approach with
vertical guidance (APV) based on WAAS, published
on RNAV (GPS) approach charts. This procedure
takes advantage of the precise lateral guidance
available from WAAS. The minima is published as a
decision altitude (DA).
LUAW-
(See LINE UP AND WAIT.)