I try to make each blog entry understandable in itself, even to people who aren't familiar with aviation abbreviations, but some unexplained jargon creeps in. Sometimes I think that I've explained something recently enough, or I'm in a hurry, or I forget altogether that something is an abbreviation. These things become words unto themselves after a while.
Some of the expanded abbreviations don't match the letters in the abbreviation. That's just the way life is. If I haven't expanded a particular abbreviation in the list below then either it doesn't stand for anything worth expanding, or I forget what it stands for. Definitions given are not official, complete or completely accurate, just enough to allow you to understand them in context. Some of the terms only apply in Canada and/or may mean different things in other countries. If there's no pronunciation, either I forgot to put one or I only use the abbreviation in writing and don't say it out loud.
See (or add to) the comments for variation in usage or pronunciation and pedantic expansions on the definitions.
A&P (eh 'n' pee) - American equivalent of AME
ADF (eh-dee-eff) - Automatic Direction Finder - cockpit navigation instrument that uses ground-based radio beacons. It can also be used to listen to AM radio.
AME (eh-em-ee) - person certified to supervise and sign for repairs and modifications done to aircraft
AMO (eh-em-oh) - licenced airplane repair shop
ATIS (eh-tiss) - a recorded message broadcast at some airports describing the weather conditions and the runway in use
CAME - Civil Aviation Medical Examiner - a doctor who is licenced to certify pilots fit or unfit for duty
CARs (cars) - Canadian Aviation Regulations - the rules of the air for Canadian pilots
CFS (see-eff-ess) - book listing facilities (runway, frequencies, services) information for Canadian aerodromes
ETA (ee-tee-eh) - Estimated Time of Arrival - when I think I will get there
ETE (ee-tee-ee) - Estimated Time Enroute - how much longer I think it will take to get there
FA (eff-eh) - Flight Attendant - a person other than a pilot who is responsible for passenger safety during a flight
FAF (faff) - Final Approach Fix - a point lined up with the runway a few miles back
FBO (eff-bee-oh) - Fixed Base Operator - an airplane service station at an airport
FO (eff-oh) - First Officer - a pilot who is second-in-command of an aircraft
FSS (eff-ess-ess) - 1. Flight Service Station 2. Flight Service Specialist - Source of aviation information such as weather
GFA (gee-eff-eh) - Graphical Area Forecast- A regional forecast in the form of a weather map
GPS (gee-pee-ess) - Global Positioning System - Usually refers to the GPS receiver, an instrument that provides navigation information
GPU (gee-pee-you) - Ground Power Unit - A cart with its own power that can be connected to an airplane on the ground to provide power to electrical systems or an extra boost for starting engines
IFR (eye-eff-are) - Instrument Flight Rules - 1. flying with reference to instruments alone, 2. IMC 3. capable (pilot, aircraft, etc) of #1
IMC (eye-em-see) - Instrument Meteorological Conditions - weather that requires IFR #1
LNAV (el-nav) - Lateral Navigation - A type of GPS approach
MDA (em-dee-eh) - Minimum Descent Altitude - Lowest altitude a pilot may legally descend to before seeing the runway
METAR (may-tar or meh-tar) - an hourly report on weather at an aerodrome
NDB (en-dee-bee) - Non-Directional Beacon - ground-based navigational beacon. Occasionally misused to mean ADF
NOTAM (no-tam or no-t'm) - an advisory of a change in procedure or a non-weather hazard to aviation
PIC (pee-eye-see) - Pilot in Command - 1. the crewmember on an airplane who has ultimate responsibility for the flight, regardless of who is actually manipulating the controls 2. time logged by a pilot while acting in that capacity
PPC (pee-pee-see) - Pilot Proficiency Check - 1. A recurring flight test to establish and maintain commercial qualifications on a particular type of airplane 2. the qualification thereby obtained 3. (verb) to arrange and pay for such qualifications
PRM (pee-are-em) - Person Responsible for Maintenance - the company official who is legally liable if the aircraft is not properly maintained
RNAV (are-nav) - navigation not dependent on ground facilities, nowadays usually GPS
TAC (tack) - Terminal Aerodrome Chart - a 1:25,000 chart for VFR navigation in the United States near a major aerodrome
TAF (taff) - a forecast for weather in the immediate area of an aerodrome over the next 12 to 36 hours
TC - Transport Canada - the regulatory authority that governs aviation in Canada
TSB - Transportation Safety Bureau - the Canadian body that investigates aviation accidents and makes safety recommendations
TT - Total Time - the total number of hours logged by a pilot in all aircraft
UTC (you-tee-see) - Coordinated Universal Time - a time that is the same all over the world, regardless of time zone or Daylight Savings status
VFR (vee-eff-are) - Visual Flight Rules - 1. flying by looking out the window, 2. weather that allows #1, 3. only capable (pilot, aircraft, airport, etc.) of #1 (as opposed to IFR)
VMC (vee-em-see) - Visual Meteorological Conditions - Weather that allows VFR #1
VNC (vee-en-see) - 1:50,000 scale VFR Canadian aviation navigation chart
VOR (vee-oh-are) - 1. a type of navigational beacon 2. aircraft navigational instrument that receives its information from 1
VTA (vee-tee-eh) - 1:25,000 scale VFR navigation chart for Canada
YQT (why-queue-tee) - if it's three letters and starts with Y or Z it's probably a Canadian airport identifier. It doesn't stand for anything, just represents that airport, which usually I will have already named before using this form. YQT is Thunder Bay. These aren't usually spoken in conversation unless the name of the airport is longer or harder to pronounce than the identifier.
Z or Zulu (pronounced "zoo-loo" in either form) - UTC
I'll update this as I use more abbreviations. If any explanations are missing, wrong or unclear, please leave a comment on this blog entry, and I'll add, fix or explain it. Unless you're just being pedantic, in which case I'll leave your comment for people who like that sort of thing.
If the jargon you don't understand isn't an abbreviation, try this Aviation Dictionary website.