background image

Pilot/Controller Glossary 

6/17/21 

LATERAL SEPARATION

 The lateral spacing of 

aircraft at the same altitude by requiring operation on 
different routes or in different geographical locations. 

(See SEPARATION.) 

LDA

 

(See LOCALIZER TYPE DIRECTIONAL AID.) 

(See LANDING DISTANCE AVAILABLE.) 

(See ICAO Term LANDING DISTANCE 

AVAILABLE.) 

LF

 

(See LOW FREQUENCY.) 

LIGHTED AIRPORT

 An airport where runway and 

obstruction lighting is available. 

(See AIRPORT LIGHTING.) 

(Refer to AIM.) 

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. 

(Refer to AIM.) 

LIGHT-SPORT AIRCRAFT (LSA)

 An 

FAA-registered aircraft, other than a helicopter or 
powered-lift, that meets certain weight and 
performance. Principally it is a single

engine aircraft 

with a maximum of two seats and weighing no more 
than 1,430 pounds if intended for operation on water, 
or 1,320 pounds if not. It must be of simple design 
(fixed landing gear (except if intended for operations 
on water or a glider), piston powered, 
nonpressurized, with a fixed or ground adjustable 
propeller). Performance is also limited to a maximum 
airspeed in level flight of not more than 120 knots 
calibrated airspeed (CAS), have a maximum 
never-exceed speed of not more than 120 knots CAS 
for a glider, and have a maximum stalling speed, 
without the use of lift-enhancing devices of not more 
than 45 knots CAS. It may be certificated as either 
Experimental LSA or as a Special LSA aircraft. A 
minimum of a sport pilot certificate is required to 
operate light-sport aircraft. 

(Refer to 14 CFR Part 1, §1.1.) 

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. 

(See CLEARED FOR TAKEOFF.) 

LOCAL AIRPORT ADVISORY (LAA)

 A service 

available only in Alaska and provided by facilities 
that are located on the landing airport, have a discrete 
ground

to

air communication frequency or the 

tower frequency when the tower is closed, automated 
weather reporting with voice broadcasting, and a 
continuous ASOS/AWOS data display, other contin-
uous direct reading instruments, or manual 
observations available to the specialist. 

(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. 

(See TRAFFIC PATTERN.) 

LOCALIZER

 The component of an ILS which 

provides course guidance to the runway. 

(See INSTRUMENT LANDING SYSTEM.) 
(See ICAO term LOCALIZER COURSE.) 
(Refer to AIM.) 

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 aligned within 3

 of the runway alignment. 

LOCALIZER TYPE DIRECTIONAL AID (LDA)

 

A localizer with an angular offset that exceeds 3

 of 

the runway alignment, used for nonprecision 
instrument approaches with utility and accuracy 
comparable to a localizer, but which are not part of a 
complete ILS. 

(Refer to AIM.) 

LOCALIZER TYPE DIRECTIONAL AID (LDA) 
PRECISION RUNWAY MONITOR (PRM) 
APPROACH

 An approach, which includes a 

glideslope, used in conjunction with an ILS PRM, 
RNAV PRM  or GLS PRM approach to an adjacent 
runway to conduct Simultaneous Offset Instrument 
Approaches (SOIA) to parallel runways whose 

PCG L