Glossary "A"


A relative location approximately at right angles to the logitudinal axis of an aircraft.


To terminate an operation prematurely when it is seen that the desired result will not occur.

Absolute Altitude

The actual distance between an aircraft and the terrain over which it is flying.

AC (Advisory Circular)

An FAA publication that informs the aviation public, in a systematic way, of nonregulatory material.

AC 43.13-1A

An advisory circular in book form issued by the FAA, giving examples of acceptable methods, techniques, and practices for aircraft inspection and repair.


An occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage. (NTSB 830.2)

AD (Airworthiness Directive)

A regulatory notice sent out by the FAA to the registered owner of an aircraft informing him or her of a condition that prevents the aircraft from meeting its conditions for airworthiness. Compliance requirements will be stated in the AD.





The FAA Administrator or any person to whom he or she has delegated authority in the matter concerned.


A person who operates or travels in a balloon or airship.


The branch of science that deals with flight and with the operations of all types of aircraft.


A device supported in the air by displacing more than its own weight of air.

AFSS (Automated Flight Service Station)

An air traffic facility that provides pilot briefings and numerous other services.


Above ground level.


A device that is used or intended to
be used for flight in the air.


An area of land or water that is used
for the landing and takeoff of an aircraft.

Altimeter Setting

The station pressure (barometric pressure at the location the reading
is taken) which has been corrected for the height of the station above sea level.






Ambient Air

Air surrounding the outside of a balloon envelope.


An instrument used to measure the velocity of moving air.

Apex Line

A line attached to the top of most
balloons to assist in inflation or deflation. Also called crown line or top handling line.


Approved by the FAA Administrator or person authorized by the Administrator.

Archimedes' Principle

The Greek mathematician's principle of buoyancy, which states that an object (a balloon) immersed in a fluid (the air) loses as much of its own weight as the weight of the fluid it replaces.


Air Traffic Control.

ATIS (Automatic Terminal Information Service)

The continuous broadcast (by radio or telephone) of recorded noncontrol, essential but routine, information in selected terminal areas.


The branch of science, business, or technology that deals with any part of the operation of machines that fly through the air.

AWOS (Automatic Weather Observing System)

Continuous broadcast (by radio or telephone) of weather conditions at selected locations.




 ŠAvStop Online Magazine                                                                                                                                                       Contact Us              Return To Books

AvStop Aviation News and Resource Online Magazine

Grab this Headline Animator