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
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.
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)
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
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.
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.
Air surrounding the outside of a
An instrument used to measure
the velocity of moving air.
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
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
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
Continuous broadcast (by radio or
telephone) of weather conditions at selected