This is abbreviations I have met in connection with aviation.
ACAS Aircraft Collision Avoidance System
ADF Automatic Direction Finder
AFIS Aerodrome Flight Information Service
AFM Airplane Flight Manual
AGC Automatic Gain Control
AHRS Attitude and Heading Reference Systems
AIP Aeronautical Information Publication
AIS Aeronautical Information Service
ALT Altitude
APRS Automatic Position Reporting System
ASDA Accelerate-Stop Distance Available
ATC Air Traffic Control
ATIS Automatic Terminal Information Service
ATPL Air Transport Pilot License
ATZ Aerodrome Traffic Zone
BFO Beat Frequency Oscillator
CAS Calibrated Airspeed
CPL Commercial Pilot License
CST Central Standard Time
CTA Control Area
CTR Control Zone
CVR Cockpit Voice Recorder
DOC Designated Operational Coverage
DME Distance-Measuring Equipment
EAS Equivalent Airspeed
EASA European Aviation Safety Agency
EFIS Electronic Flight Information System
EGPWS Enhanced Ground-Proximity Warning System
FAA Federal Aviation Administration
FADEC Full Authority Digital Electronic Control
FADEC Full Authority Digital Engine Control
FAR Federal Aviation Regulations
FCL Flight Crew Licensing
FDR Flight Data Recorder
FIR Flight Information Region
FIS Flight Information Service
FL Flight Level
FTO Flight Training Organisation
GAFOR General Aviation Forecast
GCA Ground Controlled Approach
GPS Global Positioning System
GS Glideslope
GS Ground Speed
HWC Head Wind Component
IATA International Air Transport Association
ICAO International Civil Aviation Organisation
IFR Instrument Flight Rules
ILS Instrument Landing System
IMC Instrument Meteorological Conditions
JAA Joint Aviation Authorities
JAR Joint Aviation Requirements
KCAS Knots Calibrated Airspeed
KEAS Knots Equivalent Airspeed
KIAS Knots Indicated Airspeed
KTAS Knots True Airspeed
LDA Landing Distance Available
LF Limit Load Factor
MCC Multi Crew Cooperation
ME Multi Engine
METAR METeorological Aerodrome Report
MHZ Mega Hertz
MPA Multi Pilot Aeroplane
MTOM Maximum Take-Off Mass (Europe)
MTOW Maximum Take-Off Weight (USA)
NOTAM Notices to Airmen
OAT Outside Air Temperature
PFC Proficiency Check
PIC Pilot In Command
POH Pilots Operating Handbook
PPL Private Pilot License
PPR Prior Permission Required
QA Quality Assurance
QC Quality Control
RNAV Area Navigation
RVR Runway Visual Range
SEP Single Engine Piston
SMOH Since Major Overhaul
SPA Single Pilot Aeroplane
TAF Terminal Aerodrome Forecast
TAS True Airspeed
TAWS Terrain Awareness Warning System
TBO Time Between Overhaul
TCAS Traffic alert and Collision Avoidance System
TMG Touring Motor Glider
TODA Take-Off Distance Available
TORA Take-Off Run Available
TZ Time Zone
UAV Unmanned Aerial Vehicle
UHF Ultra High Frequency
ULF Ultimate Load Factor
UTC Universal Time Coordinated
VFG VFR Flight Guide
VFR Visual Flight Rules
VHF Very High Frequency
VMC Visual Meteorological Conditions
VOLMET Volume Meteorological
VOR VHF Omnidirectional Range
VP Variable Pitch
WCA Wind Correction Angle
W/V Winddirection/Velocity
XWC Cross Wind Component