l Litre(s) (1 litre = 0.264 US Gallon = 0.220 Imperial Gallon)
L/D Lift/drag ratio; measure of aerodynamic efficiency
LABS Low altitude bombing system; aka 'toss bombing'
LAH Light attack helicopter
LAN Local area network
LANTIRN Low altitude navigation and targeting infra-red at night
LAPES Low altitude parachute extraction system
Laser Light amplification by stimulated emission of radiation
LAT Latitude
LAU Launcher unit (US)
lb Pound, unit of weight (0.454 kg)
lbf Pounds force (engine thrust rating)
lbs Pounds; re: lb
LBA Luftfahrtbundesamt; German civil aviation authority
LCD Liquid crystal display
LCG Load classification group
LCN Load classification number; represents maximum load an aircraft imposes on runway
LDA Landing distance available
LDGW Landing weight
LED Light emitting diode
LEO Low Earth orbit
LERX Leading edge root extension
LEX Leading edge extension
LF Low frequency
LFC Laminar flow control
LGB Laser guided bomb
LGT Light
LH Light helicopter
LHA Large helicopter assault carrier (USN)
LifEx Life extension
lift dumper Flat plate, raised from upper surface of wing after landing to destroy lift
LINS Laser inertial navigation system
LL Low lead
LLGB Launch & leave guided bomb
also:   low-level guided bomb
LLLGB Low-level laser guided bomb
LLL(TV) Low light level (TV)
LMTR Laser marker and target ranger
LO Low observable
load factor Number of seats occupied as a percentage of seats available
also:   nett lift on the aircraft, expressed as a multiple of its weight
localiser Directional guidance element of an ILS
LOH Light observation helicopter
LoI Letter of intent
loiter Flight for maximum endurance; significantly below cruising speed
LO-LO-LO Mission profile in which ingress, attack and egress are undertaken at low level
LONG Longitude
Loran Long range navigation
LOROP Long range oblique photography
LOS Line of sight
LoTEx Life of type extension
LOx Liquid oxygen
low observables Structures and materials designed to reduce signatures (radar, visual, noise, infrared and emissions from aircraft); aka 'stealth'
LP Low Pressure
LPC Low pressure compressor (jet engine)
LPI Low probability of intercept (stealth radar)
LPT Low pressure turbine (jet engine)
LRC Long range cruise
LRGB Long range guided bomb
LRMP Long range maritime patrol
LRMTS Laser ranger and marked-target seeker
LRPA Long range patrol aircraft
LRU Line replaceable unit
LSA Light sport aircraft
LT Local time
Ltd Limited (company)
LTD Laser target designator
LWR Laser warning receiver
LZ Landing zone
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Glossary