Aviation Acronyms

We help you decode pilot-speak and some of the most popular aviation acronyms.

I’ve always been partial to simplicity when attempting to solve life’s biggest challenges, and for me, learning a new language has been one of the toughest I’ve ever undertaken. What I didn’t realize when I learned to fly was that I was also taking on a new language, “aviation speak,” as well.

I was young and up for the challenge. It probably didn’t hurt that I was working my way through college at the time, and my mind was wide-open to all the new ­information—I envy that “me” today. It wasn’t easy, though, and as I ­progressed through my ratings and certificates, working my way to my first flight-instructor job, I kept wondering, “Why isn’t all this stuff codified somewhere?”

In the mid-1980s, I struck pay dirt. I was a new flight instructor looking for ways to help my students ­understand the baffling language of aviation. In my research I spent a lot of time combing the ­appendices of the FAA-sanctioned textbooks of the time, ­including the Pilot’s Handbook of Aeronautical Knowledge, Instrument Pilot Handbook and beyond.

One day, I was speaking with a colleague from the east coast of Florida, Deborah Balter, who taught aspiring pilots for whom English was a second language. She told me she’d put together a loose, spiral-bound “dictionary” of ­aeronautical terms and acronyms. It was two volumes, more than a thousand pages. I had to get my hands on it for my own students. I still have it in my library.

Years later, a venerable aviation publishing house—Washington State-based Aviation Supplies and Academics (ASA)—produced its own Dictionary of Aeronautical Terms (compiled and edited by Dale Crane). From AAR (airport arrival rate) to ZFW (zero-fuel weight), this ­dictionary can handle just about any aviation-­language question you throw at it. And though it focuses the bulk of its 746 pages on whole words and phrases, it does not shortchange those searching for help with acronyms, the shorthand of aviation. Every pilot, mechanic or air ­traffic controller (ATC—ha!) has his or her favorite acronym; being a fan of language, I’m no slouch. What’s high on my list? Here are just a few samples:

A&P: Airframe-and-powerplant mechanic. It’s an 18-month journey at a minimum to earn a Federal Aviation Administration (FAA) A&P certificate. If you’re an aspiring pilot, it’s important to know the A&P who works on the airplanes you fly. When there’s a discrepancy—we call that a “squawk”—or a complete malfunction, this is the person who will be on the front line making the fix. If the repair was relatively minor, the A&P can even sign off the airplane as ready to fly again. Need someone to sign off that major repair? You’ll have to step it up in the shop to the person holding the Inspection Authorization (IA) rating. The IA verifies and signs off major repairs, modifications, and the annual or 100-hour aircraft inspections.

ADS-B In and Out: Automatic (happens ­without your help) dependent (on satellite and wide-area ­augmentation systems) surveillance (listening for ­traffic and weather)—broadcast (always sending, no need for interrogation). ADS-B Out is required after December 31, 2019, in US airspace for any aircraft that wants to operate in controlled airspace, with certain exceptions. The “in” component brings near-real-time weather and traffic to the cockpit of every equipped aircraft. ADS-B is just one part of an epic upgrade that has been going on inside the NAS (National Airspace System) for more than a decade. It’s one solution to the capacity problems we face with the advent of UAVs (unmanned aerial vehicles).

AGL: Above ground level. Anytime you see an altitude with AGL following it, you know it has been measured from the ground, which could be at the top of a mountain or the bottom of Death Valley. Typically seen when trying to measure the gap between the ground and the first layer of clouds in the sky, it’s useful information when you are determining if conditions are flyable by reference to the ground (VFR, or visual flight rules).

ATIS: Automatic terminal information service. Want the weather at a major airport and its local notices to airmen (notams)? Tune in the ATIS frequency, and you’ll hear it all, recorded in a real voice at most tower-controlled airports and fully computerized at some ­towered airports and many ­nontowered ­airports (though the latter is ­technically an AWOS, or automated weather observing system).

BARO: Barometric, as in pneumatic air pressure measuring the absolute height of the atmosphere. You find BARO in weather reports and when you check in with ATC. Aircraft altimeters are ­barometric- pressure-measuring devices, at their core. In the US, we correct our ­altimeters for nonstandard barometric pressure when flying below 18,000 feet above mean sea level (MSL). When flying at 18,000 feet or above, all altimeters are set to 29.92 inches in the US and 1013 hPa in the rest of the world.

BHP: Brake horsepower. Yep, just like with piston-powered gasoline engines used in automobiles, aircraft piston engines still express power in how many horses are “under the cowl.” Specifically, it’s the power delivered to the main output drive or propeller shaft of an aircraft engine.

CAT: Clear air turbulence. This is the kind of turbulence that causes many of the serious passenger and crew injuries in the skies. Where two air masses meet in a ­cloudless sky, there is often unseen ­turbulence. These can be vertical or horizontal flows of air. Mountains can also induce waves of high-speed air downwind, and sometimes ­swirling rotors of air can develop that have the power to toss aircraft around. Finally, the unseen wake turbulence of heavy aircraft can catch other aircraft off guard and result in dangerously violent turbulence.

CG: Center of gravity. Everything that stands has a center fulcrum on which it balances, and aircraft are no exception. The CG is the point at which the algebraic sum of the moments around it equal zero, if you are a mathematician (or just into that stuff). I find it easier to measure from the diagram and tables in my pilot’s operating handbook (POH). The CG line shifts forward and aft of its perfect balance point based on how I load my aircraft with people, fuel and baggage, and if I’m not careful, I know it can shift so far forward that my nosewheel won’t come up off the runway on takeoff—or so far back, I risk a stall because the nose won’t come down.

That’s just a sample of the ABCs of aviation acronyms. Want a full A-to-Z list? Find yourself a copy of ASA’s Dictionary of Aeronautical Terms from asa2fly.com.


While you’re at it, try using a few aviation mnemonics: catchy phrases that abbreviate the high points of checklists pilots use to get an aircraft into the air. Always have a full physical copy of the list in front of you to back up your memory. You really want to make sure every critical item is checked, every important switch flipped and every number acknowledged. Here are a few classic mnemonics that work for me.

Before you fly:

PAVE your way over the risks (thank you John and Martha King, aviation-risk- management experts) by asking questions about:



enVironment: SACrED WiNd, RAW FAT

External pressures: PAWT (passengers, airspace, weather, time), CRAFTS, then DECIDE

A pilot’s honest health meter: I’M SAFE

Illness: Is the pilot suffering from any illness or symptoms of an illness which might affect them in flight?

Medication: Is the pilot currently taking any drugs (prescription or over-the-counter)?

Stress: Are there psychological or emotional factors which might affect the pilot’s performance?

Alcohol: Did they consider their alcohol consumption within the last 8 to 24 hours (.04 blood alcohol level is the FAA limit)?

Fatigue: Has the pilot had sufficient sleep and rest in the recent past?

Eating: Is the pilot sufficiently nourished?

Paperwork in the aircraft to fly: AROW

Airworthiness certificate


Operating Handbook (­sometimes known as the POH)

Weight and ­balance for that specific aircraft

Operational VFR equipment needed to fly: GOOSE A CAT

Gas gauge

Oil temperature

Oil pressure

Seat belts




Airspeed indicator


Weather briefing: SACrED WiNd


Adverse conditions

Current weather

En route forecast

Destination terminal forecast

Winds aloft


Preflight information required: RAW FAT

Runway lengths



Fuel requirements

ATC delays

Takeoff/landing distance data

In the Air:

Flight Clearance: CRAFTS







Take stock of ­external pressures: PAWT

Passengers: Are they ready, able and considerate of the pilot’s sterile ­cockpit needs?

Airspace: Is it open and navigable?

Weather: Will it cooperate along the route of flight?

Time: Is there enough to complete the ­mission before other parameters listed above change?

DECIDE model for decision-making:

Detect a change needing attention.

Estimate the need to counter or react to change.

Choose the most desirable outcome for the flight.

Identify actions to successfully control the change.

Do something to adapt to the change.

Evaluate the effect of the action.

This story appeared in the Learn to Fly Special Issue of Flying Magazine


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