See foreign object damage.
Cloud consisting of numerous minute water droplets and based at the surface; droplets are
small enough to be suspended in the earth's atmosphere indefinitely. (Unlike drizzle, it does
not fall to the surface. Fog differs
Automated Weather Observing System (AWOS)
Automated weather reporting system consisting of various sensors, a processor, a computergenerated voice subsystem, and a transmitter to broadcast weather data.
Automatic dependent surveillancebroadcast (ADS-B)
Attitude and heading reference system (AHRS)
A system composed of three-axis sensors that provide heading, attitude, and yaw information
for aircraft. AHRS are designed to replace traditional mechanical gyroscopic flight
instruments and provide superior r
A method of augmenting the GPS integrity solution by using a nonsatellite input source. To
ensure that baro-aiding is available, the current altimeter setting must be entered as described
in the operating manual.
A scale on th
See Automated Weather Observing System.
Axes of an aircraft
Three imaginary lines that pass through an aircraft's center of gravity. The axes can be
considered as imaginary axles around which the aircraft rotates. The three axes pass through
The ratio of the mass airflow in pounds per second through the fan section of a turbofan
engine to the mass airflow that passes through the gas generator portion of the engine.
Cabin pressure in terms of equivalent altitude abo
A horizontal surface mounted ahead of the main wing to provide longitudinal stability and
control. It may be a fixed, movable, or variable geometry surface, with or without control
A configuration in which the span of
Center of gravity limits
The specified forward and aft points within which the CG must be located during flight.
These limits are indicated on pertinent airplane specifications.
Center of gravity range
The distance between the forward and aft CG limits in
Changeover point (COP)
A point along the route or airway segment between two adjacent navigation facilities or
waypoints where changeover in navigation guidance should occur.
A tool that is used as a human factors aid in aviation safety. It is a
Area forecast (FA)
A report that gives a picture of clouds, general weather conditions, and visual meteorological
conditions (VMC) expected over a large area encompassing several states.
Area navigation (RNAV)
Allows a pilot to fly a selected course to a
See airport surveillance radar.
Also known as P-factor. A tendency for an aircraft to yaw to the left due to the descending
propeller blade on the right producing more thrust than the ascending blade on the left. This
occurs when the
Angle of incidence
The angle formed by the chord line of the wing and a line parallel to the longitudinal axis of
A downward slant from root to tip of an aircraft's wing or horizontal tail surface.
A complete inspe
Airport/Facility Directory (A/FD)
An FAA publication containing information on all airports, communications, and NAVAIDs.
Airport surface detection equipment (ASDE)
Radar equipment specifically designed to detect all principal features and traffic on the
A propeller with blades whose pitch can be adjusted on the ground with the engine not
running, but which cannot be adjusted in flight. Also referred to as a ground adjustable
propeller. Sometimes also used to refer to constant-s
Any surface, such as a wing, propeller, rudder, or even a trim tab, which provides
aerodynamic force when it interacts with a moving stream of air.
An extensive body of air having fairly uniform properties of temperature and moisture.
Aeronautical decision-making (ADM)
A systematic approach to the mental process used by pilots to consistently determine the best
course of action in response to a given set of circumstances.
See Airport/Facility Directory.
An irregular im
The distance required to accelerate to V1 with all engines at takeoff power, experience an
engine failure at V1, and continue the takeoff on the remaining engine(s). The runway
required includes the distance required to climb to 35
A differential pressure gauge that measures the dynamic pressure of the air through which the
aircraft is flying. Displays the craft's airspeed, typically in knots, to the pilot.
Air traffic control radar beacon system (ATCRBS)
Information the global positioning system (GPS) receiver can obtain from one satellite which
describes the approximate orbital positioning of all satellites in the constellation. This
information is necessary for the GPS receiver to know what
The pressure in the area immediately surrounding the aircraft.
The temperature in the area immediately surrounding the aircraft.
See aviation medical examiner.
The circulation date and revision num
Control tower position responsible for transmitting departure clearances to IFR flights.
The fix, point, or location to which an aircraft is cleared when issued an air traffic clearance.
Clearance on request
An IFR clear
Class C airspace
Airspace from the surface to 4,000 feet above the airport elevation (charted in MSL)
surrounding those airports having an operational control tower, serviced by radar approach
control, and having a certain number of IFR operations or pass
A special type of pressure altimeter used to send a signal to the air traffic controller on the
ground, showing the pressure altitude the aircraft is flying.
Engine pressure ratio (EPR)
The ratio of turbine discharge pressure divided by
Airspeed equivalent to CAS in standard atmosphere at sea level. As the airspeed and pressure
altitude increase, the CAS becomes higher than it should be, and a correction for compression
must be subtracted from the CAS.
The horizontal, movable primary control surface in the tail section, or empennage, of an
airplane. The elevator is hinged to the trailing edge of the fixed horizontal stabilizer.
The sensation of being in a climb or descent, cau
The curve created when plotting induced drag and parasite drag.
Angle between heading and track.
See Domestic Reduced Vertical Separation Minimum.
See direct user access terminal system.
Transmitting on one freque
Inaccurate visual information for aligning the aircraft, caused by various natural and
geometric formations that disorient the pilot from the actual horizon.
See flight director indicator.
Class E airspace areas that exte
Propellers with fixed blade angles. Fixed-pitch propellers are designed as climb propellers,
cruise propellers, or standard propellers.
A fixed, nozzle shaped opening near the leading edge of a wing that ducts air onto th
Flight director indicator (FDI)
One of the major components of a flight director system, it provides steering commands that
the pilot (or the autopilot, if coupled) follows.
Flight level (FL)
A measure of altitude (in hundreds of feet) used by aircraft fl