The curriculum
2,678 terms. Where the regulation defines a term (14 CFR 1.1 and 1.2, 280 of them), its definition is quoted word for word, and it governs. The FAA handbooks' definitions follow as guidance, each with the page of the handbook that prints it.
A widely used type of seal made in the form of a rubber ring with a round cross section. An O-ring seals in both directions, and it can be used as a packing or a gasket.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
Taught in PP-A Procedures.
A shock wave that forms on a sharp-pointed object moving through air at a speed greater than the speed of sound. Air passing through an oblique shock wave is slowed down, but not to a subsonic speed, and its static pressure is increased.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
A pressure wave that forms on a sharp-pointed object when air flows past it at a supersonic speed.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
A view that is similar to an isometric view except with two of the three drawing axes always at right angles to each other.
A preplanned instrument flight rule (IFR) departure procedure printed for pilot use in textual or graphic form to provide obstruction clearance via the least onerous route from the terminal area to the appropriate en route structure. ODPs are recommended for obstruction clearance and may be flown without ATC clearance unless an alternate departure procedure (SID or radar vector) has been specifically assigned by ATC.
Lights that can be found both on and off an airport to identify obstructions.
A frontal occlusion occurs when a fast-moving cold front catches up with a slow moving warm front. The difference in temperature within each frontal system is a major factor in determining whether a cold or warm front occlusion occurs.
A rating of the anti-detonation characteristics of a reciprocating engine fuel. It is based on the performance of the fuel in a special test engine. When a fuel is given a dual rating such as 80/87, the first number is its anti-detonating rating with a lean fuel-air mixture, and the higher number is its rating with a rich mixture. Open angle. An angle in which sheet metal is bent less than 90°.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
A system used to rate the antidetonation characteristics of a reciprocating engine fuel. Fuel with an octane rating of 80 performs in a laboratory test engine the same as the fuel made of a mixture of 80% iso-octane and 20% heptanes.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
The portion of an automobile speedometer that indicates the distance traveled.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
See obstacle departure procedures.
OEI means one engine inoperative.
Crank arms on a reciprocating engine crankshaft. The arms, or throws, to which the connecting rods and pistons are attached are offset from the center of the crankshaft to move the pistons in and out of the cylinder. The amount of the offset determines the stroke of the engine.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
The standard unit used to measure resistance.
Taught in GEN-A Quick reference, GEN-A Concepts, AF-K Concepts, GEN-H Concepts.
Explains the relationship between voltage, current, and resistance in an electrical circuit, and states that current flow in an electrical circuit is directly proportional to the amount of voltage applied to the circuit.
Taught in GEN-A Quick reference, GEN-A Concepts, AF-K Concepts, GEN-H Concepts.
A current measuring instrument that provides its own source (self-excited) of power.
Taught in AF-K Quick reference, AF-M Concepts, AF-M Procedures, GEN-K Concepts, PP-E Concepts, GEN-A Procedures and 3 more.
A method of measuring the contents in parts per million of various chemical elements in oil. A sample of the oil is burned in an electric arc, and the resulting light is analyzed with a spectroscope which identifies the chemical elements in the oil and gives an indication of the amount of each element. This type of oil analysis is called a spectrometric oil analysis program, or SOAP.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
Taught in PP-G Quick reference.
A type of roller bearing installation in a gas turbine engine in which the outer race is installed in an oil damper compartment whose inside diameter is a few thousandths of an inch larger than the outside diameter of the outer race. Oil under pressure fills the oil damper compartment and allows the bearing to compensate for sight misalignment and to absorb vibrations of the shaft.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
A method of temporarily decreasing the viscosity of the lubricating oil to make it possible to start a reciprocating engine when the temperature is very low. Before shutting the engine down, enough gasoline from the fuel system is mixed with the lubricating oil in the engine to dilute it so the starter can turn the engine over when the oil is cold and viscous. When the engine starts and the oil warms up, the gasoline evaporates.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
A shock absorber used on aircraft landing gear. The initial landing impact is absorbed by oil transferring from one compartment in the shock strut into another compartment through a metering orifice. The shocks of taxiing are taken up by a cushion of compressed air.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
OM means ILS outer marker.
Outer marker.
Guidance: Pilot's Handbook of Aeronautical Knowledge, p. G-22
The failure to anticipate significant instrument indications following attitude changes; for example, concentrating on pitch control while forgetting about heading or roll information, resulting in erratic control of heading and bank.
A maintenance program that closely monitors the operating condition of an engine and allows major repairs or replacements to be made when engine performance deteriorates to a specific level.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
The speed condition in which the engine is turning at the rpm for which the propeller governor is set.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
A complete inspection that is required for all aircraft operated for hire every 100 hours. An annual inspection must be conducted by an A&P mechanic with Inspection Authorization.
An inspection required by 14 CFR part 91, section 91.409 for FAA-certificated aircraft operated for hire or used for flight instruction for hire. A 100-hour inspection is identical in content to an annual inspection, but can be conducted by an aviation maintenance technician who holds an Airframe and Powerplant rating, but does not have an Inspection Authorization. See 14 CFR part 43, Appendix D for list of the items that must be included in an annual or 100-hour inspection.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
A low frequency vibration having one beat per revolution of the rotor. This vibration can be either lateral, vertical, or horizontal.
The period of time between the application of the glue and the assembly of the joint components.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
A type of selector valve that functions as an unloading valve as well as a selector valve. Open-center selector valves are installed in series, and when no unit is actuated, fluid from the pump flows through the centers of all the valves and returns to the reservoir. When a unit is selected for actuation, the center of the selector valve is shut off and the fluid from the pump goes through the selector valve into one side of the actuator. Fluid from the other side of the actuator returns to the valve and goes back to the reservoir through the other selector valves. When the actuation is completed, the selector valve is placed in its neutral position. Its center opens, and fluid from the pump flows straight through the valve.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
A fluid power system in which the selector valves are arranged in series with each other. Fluid flows from the pump through the center of the selector valves, back into the reservoir when no unit is being actuated.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
An electrical wiring installation in which the wires are tied together in bundles and clamped to the aircraft structure rather than being enclosed in conduit.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
Operate, with respect to aircraft, means use, cause to use or authorize to use aircraft, for the purpose (except as provided in § 91.13 of this chapter) of air navigation including the piloting of aircraft, with or without the right of legal control (as owner, lessee, or otherwise).
Taught in AF-F Procedures, AF-J Procedures, AF-L Procedures, AF-N Concepts, PP-A Concepts, PP-A Procedures and 2 more.
The center of gravity for an aircraft loaded and ready for flight.
One complete series of events in the operation of a turbine engine that consists of starting the engine, taking off, landing, and shutting the engine down.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
Operational control, with respect to a flight, means the exercise of authority over initiating, conducting or terminating a flight.
OPSPECS means operations specifications.
A misleading visual image. For the purpose of this handbook, the term refers to the brain’s misinterpretation of features on the ground associated with landing, which causes a pilot to misread the spatial relationships between the aircraft and the runway.
An electronic device that produces, modulates, or senses electromagnetic radiation in the ultraviolet, visible light, or infrared portions of the energy spectrum.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
Awareness of the position of the aircraft and of oneself in relation to a specific reference point.
Taught in AF-B Procedures, AF-E Procedures, PP-B Procedures, PP-D Procedures, PP-I Procedures, PP-J Procedures and 10 more.
A component in a hydraulic or pneumatic system that allows unrestricted flow in one direction, and restricted flow in the opposite direction.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
A heavier-than-air flying machine that produces lift by flapping its wings. No practical ornithopter has been built.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
A method of showing all six possible views of an object: front, top, bottom, rear, right side, and left side.
An electrical instrument that displays on the face of a cathode-ray tube the waveform of the electrical signal it is measuring.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
An inner ear organ that detects linear acceleration and gravity orientation.
The constant-volume cycle of energy transformation used by reciprocating engines. A mixture of fuel and air is drawn into the cylinder as the piston moves to the bottom of its stroke. The mixture is compressed as the piston moves upward in the cylinder, and when the piston is near the top of its stroke, the mixture is electrically ignited and burns. The burning mixture heats and expands the air inside the cylinder and forces the piston down, performing useful work. The piston then moves back up, forcing the burned gases out of the cylinder.
Aviation Maintenance Technician Handbook — Powerplant, p. G-19
Hovering a distance greater than one disk diameter above the surface. Because induced drag is greater while hovering out of ground effect, it takes more power to achieve a hover out of ground effect.
A marker beacon at or near the glideslope intercept altitude of an ILS approach. It is normally located four to seven miles from the runway threshold on the extended centerline of the runway.
A valve in the cabin of a pressurized aircraft that controls the cabin pressure by opening to relieve all pressure above that for which the cabin pressure control is set.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
Taught in AF-G Concepts, AF-G Procedures, AF-G Quick reference.
The measured or indicated air temperature (IAT) corrected for compression and friction heating. Also referred to as true air temperature.
Taught in GEN-J Procedures, AF-H Quick reference, GEN-J Quick reference.
Used for measuring outside dimensions, such as the diameter of a piece of round stock.
Over-the-top means above the layer of clouds or other obscuring phenomena forming the ceiling.
Taught in GEN-J Concepts.
A condition of excessive manifold pressure in a reciprocating engine. Overboosting occurs when the supercharger is operated at too high a speed.
Aviation Maintenance Technician Handbook — Powerplant, p. G-20
A condition in which a reciprocating engine has exceeded the maximum manifold pressure allowed by the manufacturer. Can cause damage to engine components.
Taught in PP-J Concepts, PP-J Procedures.
Using more movement in the control column than is necessary to achieve the desired pitch-and-bank condition.
To use more power than required for the purpose of achieving a faster rate of airspeed change.
A type of clutch that couples an input shaft with an output shaft. When the input shaft is driven, the output shaft rotates with it. When the output shaft is driven, the output shaft rotates with it. But when the output shaft is driven, the input shaft does not turn.
Aviation Maintenance Technician Handbook — Powerplant, p. G-20
Overseas air commerce means the carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of aircraft in the conduct or furtherance of a business or vocation, in commerce between a place in any State of the United States, or the District of Columbia, and any place in a territory or possession of the United States; or between a place in a territory or possession of the United States, and a place in any other territory or possession of the United States.
Overseas air transportation means the carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft, in commerce: (1) Between a place in a State or the District of Columbia and a place in a possession of the United States; or (2) Between a place in a possession of the United States and a place in another possession of the United States; whether that commerce moves wholly by aircraft or partly by aircraft and partly by other forms of transportation.
A speed condition in which the engine is turning at an rpm higher than that for which the propeller governor is set.
Aviation Maintenance Technician Handbook — Powerplant, p. G-20
A component in an aircraft electrical system that opens the alternator field circuit any time the alternator output voltage is too high.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
An oxyacetylene flame in which there is an excess of oxygen. The inner cone is pointed and often a hissing sound is heard.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
Taught in AF-A Quick reference.
An unstable form of oxygen produced when an electric spark passes through the air. Ozone is harmful to rubber products. Packing.A seal between two parts where there is relative motion.
Aviation Maintenance Technician Handbook — Airframe, p. G-24
Taught in AF-L Concepts.
The glossary is CC BY-SA 4.0 as an arrangement; the quoted regulation text is a work of the US Government. Handbook definitions are quoted from the FAA's handbooks, each linked to the FAA's own copy.