NGV NOZZLE GUIDE VANE (APIC APU)
NIL N1 LIMIT
NLG NOSE LANDING GEAR
NM NAUTICAL MILES
NMI NAUTICAL MILE
NO NORMALLY OPEN
NO NUMBER
NORM NORMAL
NOVRAM NON VOLATILE READ ONLY MEMORY
NPA N APU PEAK
NRV NON RETURN VALVE
NS / FSB PANEL NO SMOKING / FASTEN SEAT BELT PANEL
NS NO SMOKING
NSS NEUTRAL SHIFT SENSOR
NTC NEGATIVE TEMPERATURE COEFFICIENT
NTM NON-DESTRUCTIVE TEST MANUAL
NTSB NATIONAL TRANSPORTATION SAFETY BOARD (USA)
NTSC NATIONAL TELEVISION STANDARDS COMMITTEE
NUM NUMERICAL
NVM NON VOLATILE MEMORY
NW NOSE WHEEL
O OSCAR
O / C OPEN CIRCUIT
O / F OUTPUT PROCESSING & FAULT LOGIC
O / P OUTPUT
O / V OUT FLOW VALVE
O2 OXYGEN
OAP OUTSIDE AIR PRESSURE
OAT OUTSIDE AIR TEMPERATURE
OBD OVERBOARD
OBRM ON BOARD REPLACEABLE MODULE (MEMORY)
OBSV OBSERVATION
OC ON COURSE
OCCPNT OCCUPANT
OCR OPTICAL CHARACTER READING
OEB OPERATIONS ENGINEERING BULLETIN
OFF / R OFF / RESET
OFFR OFF / RESET
OFST OFFSET
OGV OUTLET GUIDE VANE
OHSC OVERHEAD STOWAGE COMPARTMENTS
OHU OPTICAL HEAD UNIT
OI OPERATING INSTRUCTIONS
OIK OIL QUANTITY CORRECTED
OIL HX ENGINE OIL HEAT EXCHANGER
OIP OIL PRESSURE
OIQ OIL QUANTITY
OIQH OIL CONSUMPTION
OIT OIL TEMPERATURE
OK CORRECT
OLMS OPERATIONAL LOADS MONITORING SYSTEM
OM OUTER MARKER
OMS ONBOARD MAINTENANCE SYSTEM
ONS OMEGA NAVIGATION SYSTEM
OPER OPERATING, OPERATION, OPERATIVE
OPP OPPOSITE
OPS OPERATION
OPT OPTIMUM
38 Aircraft Systems - Abbreviations and Acronyms

OPV OVER PRESSURE VALVE