A system for reserving seats on commercial flights electronically. Several airlines own and market such systems, which are used by travel agents.

A control surface located on the trailing edge of each wing tip. Deflection of these surfaces controls the roll or bank angle of the aircraft.

Any surface such as an airplane wing, aileron, or rudder designed to obtain a useful reaction from the air moving past it.

A term used to describe both the legal and mechanical status of an aircraft with regard to its readiness for flight.

An instrument which displays the altitude above mean sea level (MSL) of an aircraft.

An instrument which enables a pilot to determine the attitude of the aircraft in relation to the horizon, i.e. whether the aircraft is nose-up, nose-down, or banking left or right.

One seat flown one mile. An airliner with 100 passenger seats, flown a distance of 100 miles, represents 10,000 available seat miles (ASMs).

Anything other than passengers, carried for hire, including both mail and freight.

A device that records the sounds audible in the cockpit, as well as all radio transmissions made and received by the aircraft, and all intercom and public address announcements made in the aircraft [..]

A marketing practice in which two airlines share the same two-letter code used to identify carriers in the computer reservation systems used by travel agents.