Aviation Glossary
5,137 terms from FAA handbooks. Covers all aviation operations — Pilot, Maintenance (AMT), Rotorcraft, Glider, UAS, Weather, Rigger, Light Sport, and more. Ready for any aviation tenant type.
100-Hour Inspection
An inspection, identical in scope to an annual inspection. Must be conducted every 100 hours of flight on aircraft of under 12,500 pounds that are used for hire.
Source: FAA-H-8083-3C
14 CFR
(Title 14 of the Code of Federal Regulations. Federal regulations pertaining to aviation activity. Previously known as Federal Aviation Regulations.
Source: FAA-G-8082-22, FAA-H-8083-2A, FAA-H-8083-3C, FAA-H-8083-28B
3P
An acronym that represents the three components of the risk management cycle: Perceive, Process, Perform.
Source: FAA-H-8083-2A
A.C
Alternating current. Electrical current in which the electrons continually change their rate of flow and periodically reverse their direction.
Source: FAA-G-8082-22, FAA-H-8083-15B, FAA-H-8083-25C, FAA-H-8083-32B
A/FD
See Airport/Facility Directory.
Source: FAA-H-8083-15B, FAA-H-8083-29, FAA-H-8083-5, FAA-H-8083-16B, FAA-H-8083-25C
Abeam Fix
A fix, NAVAID, point, or object positioned approximately 90 degrees to the right or left of the aircraft track along a route of flight. Abeam indicates a general position rather than a precise point.
Source: FAA-H-8083-16B
Aborted takeoff
A takeoff that is terminated prematurely when it is determined that some condition exists that makes takeoff or further flight dangerous. of an object through the air. Aerodynamic drag is composed of both induced drag and parasite drag. See induced drag and parasite drag.
Source: FAA-H-8083-29, FAA-H-8083-31B, FAA-H-8083-5
Above ground level (AGL)
The actual height above ground level (AGL) at which the aircraft is flying.
Source: FAA-H-8083-5
Abradable strip
A strip of material in the compressor housing of some axial-flow gas turbine engines. The tip of the compressor blade touches the abradable strip, and wears, or abrades a groove in it. This groove ensures the minimum tip clearance.
Source: FAA-H-8083-32B
Abradable tip (compressor blade tip)
The tip of some axial-flow compressor blades constructed so that it will abrade, or wear away, upon contact with the compressor housing, which ensures the minimum tip clearance between the blade and the housing.
Source: FAA-H-8083-32B
Absolute accuracy
The ability to determine present position in space independently, and is most often used by pilots.
Source: FAA-H-8083-15B, FAA-H-8083-25C
Absolute altitude
The vertical distance of an airplane above the terrain or above ground level (AGL).
Source: FAA-H-8083-15B, FAA-H-8083-21A, FAA-H-8083-25C, FAA-H-8083-3C
Absolute ceiling
The altitude at which a climb is no longer possible.
Source: FAA-H-8083-3C
Absolute humidity
The actual amount of the water vapor in a mixture of air and water.
Source: FAA-H-8083-30B
Absolute pressure
Equal to gauge pressure plus atmospheric pressure. Also known as psia.
Source: FAA-H-8083-15B, FAA-H-8083-25C, FAA-H-8083-30B, FAA-H-8083-31B, FAA-H-8083-32B
Absolute pressure regulator
A valve used in a pneumatic system at the pump inlet to regulate the compressor inlet air pressure to prevent excessive speed variation and/or overspeeding of the compressor.
Source: FAA-H-8083-31B
Absolute temperature
Temperature measured relative to absolute zero. Absolute temperature scales include Kelvin and Rankine.
Source: FAA-H-8083-30B
Absolute zero
The point at which all molecular motion ceases. Absolute zero is –460 °F and –273 °C.
Source: FAA-H-8083-31B
Abstractions
Words that are general rather than specific. Aircraft is an abstraction; airplane is less abstract; jet is more specific; and jet airliner is still more specific.
Source: FAA-H-8083-9A
ACC
Active clearance control. A system for controlling the clearance between tips of the compressor and turbine blades and the case of high-performance turbofan engines. When the engine is operating at maximum power, the blade tip clearance should be minimum, and the ACC system sprays cool fan discharge air over the outside of the engine case. This causes the case to shrink enough to decrease the tip clearance. For flight conditions that do not require such close clearance, the cooling air is turned
Source: FAA-H-8083-32B
Accelerate-go distance
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 feet by which time V2 speed must be attained.
Source: FAA-H-8083-25C, FAA-H-8083-3C
Accelerate-stop distance
The distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1, and abort the takeoff and bring the airplane to a stop using braking action only (use of thrust reversing is not considered).
Source: FAA-H-8083-25C, FAA-H-8083-3C
Accelerate-Stop Distance Available (ASDA)
The runway plus stopway length declared available and suitable for the acceleration and deceleration of an airplane aborting a takeoff. Advanced Surface Movement Guidance and Control
Source: FAA-H-8083-16B
Acceleration
The amount the velocity of an object is increased by a force during each second it is acted upon by that force. Acceleration is usually measured and expressed in terms of feet per second, per second (fps²).
Source: FAA-H-8083-25C, FAA-H-8083-29, FAA-H-8083-32B, FAA-H-8083-3C, FAA-H-8083-5
Acceleration due to gravity
The acceleration of an object caused by gravity. On earth, it is measured as 32.2 feet per second per second (32.2 fps/s).
Source: FAA-H-8083-30B
Acceleration error
A magnetic compass error apparent when the aircraft accelerates while flying on an easterly or westerly heading, causing the compass card to rotate toward North.
Source: FAA-H-8083-15B, FAA-H-8083-25C
Accelerometer
A part of an inertial navigation system (INS) that accurately measures the force of acceleration in one direction.
Source: FAA-H-8083-15B, FAA-H-8083-25C
Acceptable risk
That part of identified risk that is allowed to persist without further engineering or management action. Making this decision is a difficult yet necessary responsibility for managing activity. This decision is made with full knowledge that it is the user who is exposed to this risk.
Source: FAA-H-8083-2A
Accessories
Components that are used with an engine, but are not a part of the engine itself. Units such as magnetos, carburetors, generators, and fuel pumps are commonly installed engine accessories.
Source: FAA-H-8083-3C
Accessory end
The end of a reciprocating engine on which many of the accessories are mounted. Also, called the antipropeller end.
Source: FAA-H-8083-32B
Accordion folding
The folding of the canopy for stacking in the container prior to closing.
Source: FAA-H-8083-17
Accumulator
A hydraulic component that consists of two compartments separated by a movable component, such as a piston, diaphragm, or bladder. One compartment is filled with compressed air or nitrogen, and the other is filled with hydraulic fluid and is connected into the system pressure manifold.An accumulator allows an incompressible fluid to be stored under pressure by the force produced by a compressible fluid. Its primary purposes are to act as a shock absorber in the system, and to provide a source of
Source: FAA-H-8083-31B, FAA-H-8083-32B
ACS
Airman Certification Standards
Source: FAA-G-8082-22, FAA-H-8083-25C
Actuator
A fluid power device that changes fluid pressure into mechanical motion.
Source: FAA-H-8083-31B
AD
See Airworthiness Directive. 14 CFR. See Title 14 of the Code of Federal Regulations.
Source: FAA-H-8083-5
AD (ashless dispersant) oil
A mineral-based lubricating oil used in reciprocating engines. This oil does not contain any metallic ash-forming additives, but has additives that disperse the contaminants and hold them in suspension until they can be removed by filters.
Source: FAA-H-8083-32B
ADC
Air data computer. An electronic computer in an aircraft that senses pitot pressure, static pressure, and total air temperature. It produces an indication of altitude, indicated airspeed, true airspeed, and Mach number. The output of ADC is usable by any of the engine or flight control computers.
Source: FAA-H-8083-25C, FAA-H-8083-31B, FAA-H-8083-32B
Addition
The process in which the value of one number is added to the value of another.
Source: FAA-H-8083-30B
ADDS
Aviation Digital Data Services
Source: FAA-G-8082-22, FAA-H-8083-16B
ADF
See automatic direction finder.
Source: FAA-H-8083-15B, FAA-H-8083-25C, FAA-H-8083-31B, FAA-H-8083-16B
ADI
See attitude director indicator.
Source: FAA-H-8083-15B, FAA-H-8083-25C, FAA-H-8083-31B
ADI (antidetonation injection) system
A system used with some large reciprocating engines in which a mixture of water and alcohol is sprayed into the engine with the fuel when operating at extremely high power. The air/fuel mixture is leaned to allow the engine to develop its maximum power, and the ADI fluid absorbs excessive heat when it vaporizes.
Source: FAA-H-8083-32B
Adiabatic change
A physical change that takes place within a material in which heat energy is neither added to the material, nor taken away. If a container of gas is compressed, with no heat energy added to or taken from it, the gas will become hotter; its temperature will rise.
Source: FAA-H-8083-32B
Adiabatic cooling
A process of cooling the air through expansion. For example, as air moves up slope it expands with the reduction of atmospheric pressure and cools as it expands.
Source: FAA-H-8083-25C
Adiabatic heating
A process of heating dry air through compression. For example, as air moves down a slope it is compressed, which results in an increase in temperature.
Source: FAA-H-8083-25C
ADIZ
Air Defense Identification Zone
Source: FAA-G-8082-22, FAA-H-8083-25C
Adjustable stabilizer
A stabilizer that can be adjusted in flight to trim the airplane, thereby allowing the airplane to fly hands-off at any given airspeed.
Source: FAA-H-8083-25C, FAA-H-8083-3C
Adjustable-pitch propeller
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-speed propellers that are adjustable in flight.
Source: FAA-H-8083-25C
ADM
See AERONAUTICAL DECISION MAKING. 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.
Source: FAA-G-8082-22, FAA-H-8083-15B, FAA-H-8083-25C, FAA-H-8083-29, FAA-H-8083-5
Administration (FAA)
It is specific to a particular make and model airplane by serial number and it contains operating procedures and limitations.
Source: FAA-H-8083-3C