Photo: Barry Ambrose

Aviation Lingo: A Glossary

Puzzled by terms like "airspeed" and "green aircraft"? Read this for explanations of those and dozens of other bizav words and phrases.

If you aren’t a pilot, some of the aviation-related terms you encounter may seem confusing. Here’s a glossary to help assure that when you hear words and acronyms bandied about, you’ll nod with understanding instead of pausing with puzzlement.

Aircraft, airplane: Aircraft are anything that flies—an airplane, helicopter, glider, balloon, or blimp all qualify. A plane, by the way, is a tool used to make wood smooth, and using the word “plane” in aviation circles might make you sound like a noob (a techno term, short for newbie). 

Airspeed, groundspeed: We fly in an ocean of air. Headwinds slow you down, thus a lower groundspeed (speed over the ground), while your airspeed (speed through the air) to achieve that groundspeed remains the same no matter which way the wind is blowing.

Altimeter, flight level: The altimeter measures height expressed by barometric pressure (air pressure decreases at a fairly constant rate as you climb). Above 18,000 feet, height in the U.S. is measured in Flight Levels (FL 200 equals 20,000 feet). Note that barometric altitude is not the same as true altitude. So a GPS-derived altitude will not match that displayed on an altimeter.

Approach, decision height, missed approach, go-around: Nearing an airport, the pilot will “shoot an approach,” which means flying a specific pattern that brings the aircraft to the landing zone precisely, even in poor weather. A “missed approach” means that the pilots couldn’t see the runway environment when they reached the minimum altitude (“decision height”) and had to climb away either to try again or fly to the alternate airport. A go-around is similar to a missed approach—climbing away, then returning to land—but usually is done because the pilot detected an obstacle on the runway or determined that the landing couldn't be accomplished safely.

ATC: Air Traffic Control. Controllers don’t actually control aircraft but exist mainly to keep them from running into each other. In every case, pilots have the final say, although they must comply with controller instructions except in an emergency.

Avionics: The “aircraft electronics” mostly found in the flight deck. 

Gulfstream Symmetry Flight Deck

Bleed air: Pressurized air delivered from a jet engine’s compressor section, used to run cabin environmental systems, including pressurizing the cabin, and to provide warm air to deice the wings and empennage.

Block charter: Charter flight hours purchased in volume, usually at a discount and sometimes allowing use of multiple aircraft.

Ceiling: The height of the bottom of the cloud deck, as measured above ground level.

Certification: Most aviation products must meet stringent certification requirements set by government agencies. This is for safety reasons, but also goes a long way toward explaining why aircraft, engines, and parts cost so much.

Completions/refurbs: When you buy a new aircraft, it will need to undergo “completion” (outfitting of the cabin and exterior paint). A used aircraft gets a “refurb.”

Drag: Drag causes the aircraft to resist movement through air, and it must be overcome by plenty of thrust from the engines, which is why engines need plenty of fuel. The higher you go, the more air density drops and the faster you can fly on a given level of power output, because drag drops as density drops.

EASA: The European Aviation Safety Agency, the counterpart to the U.S. FAA. 

ETA, ETE: Estimated time of arrival, estimated time en route.

FAA: The Federal Aviation Administration.

Fairing: A portion of an aircraft that smoothes airflow around aerodynamic rough spots (such as where wings join the fuselage).

FAR: Federal Aviation Regulations, which govern all aspects of aviation in the U.S.

FBO: Stands for “fixed-base operator,” which means a non-itinerant aviation service provider. FBOs primarily are the gas station at an airport and also the facility that welcomes you into the aviation infrastructure. FBOs provide many more services such as comfortable waiting areas, pilot facilities, hangars, parking, and offices.

Flaps: The moveable panels on the inner rear edge of the wing. Most jets require flaps to be extended on takeoff to help the airplane get off the ground safely. 

Fixed-wing: An airplane, as opposed to a rotary-wing aircraft (helicopter).

Fractional share: Portions of aircraft sold to multiple owners. Usually associated with a company that manages the shared operation on behalf of owners.

French terms: France had an enormous influence on early aviation and was responsible for many terms. Among them: 

Aileron: Panels attached to the rear outboard section of the wing that help the pilot bank the airplane. From the French “aleron” for little wing.

Fuselage: The part of the aircraft that includes the flight deck and cabin and to which the wings and empennage are attached. From “fuselĂ©” for spindle-shaped. 

Empennage: The tailfeathers on the back of the airplane. 

Hangar: From the French for “shed,” an indoor spot to park your aircraft. 


Nacelle: Sculpts the airflow around an engine. From the French for “little boat,” which doesn’t make much sense.

Pitot tube: Named after French hydraulic engineer Henri Pitot, for the tube that drives the airspeed indicator.

GAMA: General Aviation Manufacturers Association, which represents aircraft manufacturers, also known as original equipment manufacturers (OEMs).

General Aviation: Everything aeronautical except military and airline aviation. Business aviation is part of general aviation. General aviation is a new concept in many countries where only airlines and military flying have existed. 

Green aircraft: Newly built aircraft that have no interior fixtures or seats in the cabin and are delivered to completion centers to be outfitted according to customers’ specifications.

Gross weight, maximum takeoff weight, payload: Maximum takeoff weight (MTOW) and gross weight are used interchangeably and represent the highest allowable weight of your aircraft (a certification limit). Payload is the amount of stuff your aircraft can carry, including fuel, passengers, cargo, and anything else that isn’t already installed.

Hypoxia: The deleterious effects to your brain without oxygen, if you don’t use the oxygen masks when there is a pressurization problem, possibly due to bleed air system trouble. 

Garmin GTN 750 VFR

IFR/VFR: Instrument/Visual Flight Rules, a body of regulations (FARs) for flying when the weather is generally good (VFR) or bad (IFR). Most business jet operations are conduced under IFR, even in good weather.

Lift: What keeps the aircraft flying, generated by moving a wing or rotor blades through the air. Lack of lift leads to a stall.

Mach: How fast you’re going in relation to the speed of sound, named after Austrian physicist Ernst Mach. You can almost break the sound barrier (fly faster than Mach 1.0) in a few current business jets, but you’ll need a supersonic aircraft to do so safely and regularly. Current regulations don’t permit civil supersonic flight over most land areas because of the unavoidable noise of the resulting sonic boom.

NBAA: National Business Aviation Association, which represents business aircraft owners, operators, and associated companies.

NextGen, Cesar: The FAA’s and EASA’s plans for modernized air-traffic-control systems based on GPS navigation. Mostly, they will cost you tons of money for avionics upgrades, although they also promise to improve efficiency and safety.

NTSB: National Transportation Safety Board, an independent U.S. government body that investigates transportation accidents.

Part 91: Regulations covering aircraft operations by non-commercial entities, such as a corporation owning and operating a jet using its own pilots.

Part 135: Regulations covering aircraft operations by commercial entities, in this case unscheduled charter providers, also known as air-taxi operators. Part 121 covers scheduled airlines.

RVSM: Reduced vertical separation minima, the system being adopted worldwide to increase the number of Flight Levels available for air traffic.

SIFL: Standard Industry Fare Level rates, used to determine the value of a flight that is taxable. Another option is to use fair market or charter value.

Stall: When airflow over the wing slows down too much, it stagnates and causes a loss of lift, which can be catastrophic in a jet. 

Static display: The outdoor display of aircraft at an air show.

Squawks: Problems or discrepancies with an aircraft. If your inflight satellite phone stops working, you notify the pilots, who will write a “squawk” in the aircraft’s paperwork.

Tail number: The “license plate” or registration letters and/or numbers painted on your aircraft. Each country has its own prefix. In the U.S., it’s N, for example, and in Canada, it’s C. 


Winglet: These tilted-up devices at the outboard end of the wings help lower aerodynamic drag and thus allow jets to fly farther using the same amount of fuel.

Yoke, sidestick, joystick: The controls that pilots use to fly the airplane.