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.
The position of the rotating magnet in a magneto when the breaker points are timed to open. The E-gap (efficiency gap) angle is several degrees of magnet rotation beyond the magnet’s neutral position. At this point, the magnetic field stress is the greatest, and the change in flux is the greatest, inducing the maximum voltage in the secondary winding.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
Electronic Attitude Director Indicator.
Aviation Maintenance Technician Handbook — Airframe, p. G-13
Early ETOPS means ETOPS type design approval obtained without gaining non-ETOPS service experience on the candidate airplane-engine combination certified for ETOPS.
EAS means equivalent airspeed.
Electronic Centralized Aircraft Monitor.
Aviation Maintenance Technician Handbook — Airframe, p. G-13
Taught in PP-D Quick reference.
A special bushing used between the rear spar of certain cantilever airplane wings and the wing attachment fitting on the fuselage. The portion of the bushing that fits through the hole in the spar is slightly offset from that which passes through the holes in the fitting. By rotating the bushing, the rear spar may be moved up or down to adjust the root incidence of the wing. Eddy current damping (electrical instrument damping). Decreasing the amplitude of oscillations by the interaction of magnetic fields. In the case of a vertical-card magnetic compass, flux from the oscillating permanent magnet produces eddy currents in a damping disc or cup. The magnetic flux produced by the eddy currents opposes the flux from the permanent magnet and decreases the oscillations.
Aviation Maintenance Technician Handbook — Airframe, p. G-13
Current induced into a conductor due to a mobbing or non-uniform magnetic field.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
Taught in GEN-K Concepts, GEN-K Procedures, GEN-K Quick reference.
The decreased amplitude of oscillations by the interaction of magnetic fields. In the case of a vertical card magnetic compass, flux from the oscillating permanent magnet produces eddy currents in a damping disk or cup. The magnetic flux produced by the eddy currents opposes the flux from the permanent magnet and decreases the oscillations.
An inspection method where eddy currents are induced into the material to be tested. In aircraft manufacturing plants, eddy current is used to inspect castings, stampings, machine parts, forgings, and extrusions.
Taught in GEN-K Quick reference.
Current induced in a metal cup or disc when it is crossed by lines of flux from a moving magnet.
The distance between the center of a rivet hole and the edge of the sheet of metal.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Taught in AF-A Concepts, AF-A Procedures, AF-A Quick reference, AF-A Hands-on, AF-I Concepts, GEN-B Concepts.
Electronic engine control. An electronic fuel control for a gas turbine engine. The EEC senses the power-lever angle (PLA), engine RPM, bleed valve, and variable stator vane position, and the various engine pressures and temperatures. It meters the correct amount of fuel to the nozzles for all flight conditions, to prevent turbine over-speed and over-temperature.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
See expect-further-clearance.
See electronic flight display.
The actual distance a propeller advances in one revolution through the air.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
Electronic Flight Instrument System.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Taught in AF-H Quick reference, AF-H Concepts.
EFVS means enhanced flight vision system.
EFVS operation means an operation in which visibility conditions require an EFVS to be used in lieu of natural vision to perform an approach or landing, determine enhanced flight visibility, identify required visual references, or conduct a rollout.
Exhaust gas temperature. The temperature of the gases as they leave the cylinder of a reciprocating engine or the turbine of a gas turbine engine.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
See exhaust gas temperature.
Taught in PP-D Concepts, PP-D Quick reference, PP-C Procedures.
Electronic Horizontal Situation Indicator.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Engine Indicating and Crew Alerting System.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Engine indicating and crew alerting system. An electronic instrumentation system that monitors airframe and engine parameters and displays the essential information on a video display on the instrument panel. Only vital information is continually displayed, but when any sensed parameters fall outside of their allowable range of operation, they are automatically displayed.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
Taught in AF-H Concepts, AF-H Quick reference, PP-D Quick reference.
A form of jet pump used to pick up a liquid and move it to another location. Ejectors are used to ensure that the compartment in which the boost pumps are mounted is kept full of fuel. Part of the fuel from the boost pump flowing through the ejector produces a low pressure that pulls fuel from the main tank and forces it into the boostpump sump area.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The maximum amount of tensile load, in pounds per square inch, a material is able to withstand without being permanently deformed.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The maximum amount of tensile load, in pounds per square inch, that a material is able to withstand without permanent deformation.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
Electrical energy is converted to heat energy when an electric current flows through any form of resistance such as an electric iron, electric light, or an electric blanket.
The electrical force caused by a deficiency of electrons in one location and an excess of electrons in another. Electrical potential is measured in volts.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
A low-carbon iron alloy that contains some silicon It is used as the core for transformers, field frames for generators and alternators, and the magnetic circuit of magnetos.
Aviation Maintenance Technician Handbook — Powerplant, p. G-10
A magnet produced by an electrical current flowing through a coil of wire. The coil is normally wound around a core of soft iron which has an extremely low retentivity, allowing it to lose its magnetism as soon as the current stops flowing.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A method of transmitting energy from one location to another. Current caused by high voltage in the secondary winding of a magneto produces electric and magnetic fields which oscillate back and forth at a high frequency and extend out into space in the form of waves. These waves of electromagnetic radiation are received as interference by the radio receivers in the aircraft.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
The pressure or force that causes electrons to flow in an electrical circuit.
The force that causes electrons to move from one atom to another within an electrical circuit. Electromotive force is an electrical pressure, and it is measured in volts.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
A force that causes electrons to move from one atom to another within an electrical circuit. An electromotive force, or EMF, is the difference in the electrical pressure, or potential, that exists between two points. An EMF may be produced by converting mechanical movement, pressure, chemical, light, or heat energy into electrical energy. The basic unit of EMF is the volt.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
The actual flow of electrons in a circuit. Electrons flow from the negative terminal of a power source through the external circuit to its positive terminal. The arrowheads in semiconductor symbols point in the direction opposite to the flow of electron current.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
For the purpose of standardization, any flight instrument display that uses LCD or other image-producing system (cathode ray tube (CRT), etc.)
A field of force that exists around a charged body.
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.
Taught in GEN-C Concepts.
A spring in the elevator control system that produces a mechanical force that tries to lower the elevator. In normal flight, this spring force is overcome by the aerodynamic force from the elevator trim tab. But in slow flight with an aft CG position, the trim tab loses its effectiveness and the downspring lowers the nose to prevent a stall.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The sensation of being in a climb or descent, caused by the kind of abrupt vertical accelerations that result from up- or downdrafts.
Movable control surfaces on the trailing edge of a delta wing or a flying wing airplane. These surfaces operate together to serve as elevators, and differentially to act as ailerons.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
A self-contained radio transmitter that automatically begins transmitting on the emergency frequencies any time it is triggered by a severe impact parallel to the longitudinal axis of the aircraft.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Electromagnetic wave.
A distress or urgent condition.
Taught in AF-E Procedures, AF-F Concepts, GEN-D Concepts.
A device used to alert search and rescue services in the event of an emergency by transmitting a coded message on the 406 MHz distress frequency, which is relayed by the Cospas- Sarsat global satellite system.
Electromagnetic interference.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The section of the airplane that consists of the vertical stabilizer, the horizontal stabilizer, and the associated control surfaces.
Aviation Maintenance Technician Handbook — General, p. G-4; Pilot's Handbook of Aeronautical Knowledge, p. G-11
The tail section of an airplane.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The result of giving too much attention to a particular instrument during the cross-check, instead of relying on a combination of instruments necessary for attitude and performance information.
Induced nearsightedness that is associated with flying at night, in instrument meteorological conditions and/or reduced visibility. With nothing to focus on, the eyes automatically focus on a point just slightly ahead of the airplane.
See standard empty weight.
The weight of the airframe, engines, all permanently installed equipment, and unusable fuel. Depending upon the part of the federal regulations under which the aircraft was certificated, either the undrainable oil or full reservoir of oil is included.
Taught in GEN-C Procedures, GEN-C Quick reference, GEN-C Concepts.
The center of gravity of an aircraft when it contains only the items specified in the aircraft empty weight.
This is the center of gravity of the aircraft in the empty condition, containing only the items specified in the aircraft empty weight. This CG is an essential part of the weight and balance record of the aircraft.
Taught in GEN-C Quick reference.
The distance between the allowable forward and aft empty-weight CG limits.
Aviation Maintenance Technician Handbook — General, p. G-4; Aircraft Weight and Balance Handbook, p. G-3
A suspension of small globules of one material in another when the two materials will not mix. Oil and water will not mix, but they can be formed into an emulsion. An emulsion will separate into its components when it is allowed to sit.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
Depicted in the plan view of IAP charts, a circle which designates NAVAIDs, fixes, and intersections that are part of the en route low altitude airway structure.
Aeronautical charts for en route instrument navigation at or above 18,000 feet MSL.
Aeronautical charts for en route IFR navigation below 18,000 feet MSL.
A type of finishing material that flows out to form a smooth surface. Enamel is usually made of a pigment suspended in some form of resin. When the resin cures, it leaves a smooth, glossy protective surface.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
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.
A brake that uses the momentum of the aircraft to increase its effectiveness by wedging the shoe against the brake drum. Energizing brakes are also called servo brakes. A single-servo brake is energizing only when moving in the forward direction, and a duo-servo brake is energizing when the aircraft is moving either forward or backward.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The capacity of a physical system to perform work. There are two types of energy, kinetic and potential.
Taught in AF-F Concepts, GEN-J Quick reference, PP-H Concepts, AF-C Concepts, AF-E Concepts, AF-F Procedures and 7 more.
The ratio of turbine discharge pressure divided by compressor inlet pressure, which is used as an indication of the amount of thrust being developed by a turbine engine.
Taught in PP-D Quick reference.
A maintenance procedure in which the fuel control on a gas turbine engine is adjusted to cause the engine to produce the required EGT or EPR at a specified rpm.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
Enhanced flight visibility (EFV) means the average forward horizontal distance, from the cockpit of an aircraft in flight, at which prominent topographical objects may be clearly distinguished and identified by day or night by a pilot using an enhanced flight vision system.
Enhanced flight vision system (EFVS) means an installed aircraft system which uses an electronic means to provide a display of the forward external scene topography (the natural or manmade features of a place or region especially in a way to show their relative positions and elevation) through the use of imaging sensors, including but not limited to forward-looking infrared, millimeter wave radiometry, millimeter wave radar, or low-light level image intensification. An EFVS includes the display element, sensors, computers and power supplies, indications, and controls.
Water suspended in jet fuel. The amount of entrained water that can be held in the fuel is determined by the temperature of the fuel. When the fuel becomes cold, the water precipitates out and forms ice crystals on the fuel filter element.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A gear train in which a series of small planetary gears rotate around a central gear. More commonly called a planetary gear train.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A flexible, thermosetting resin that is made by polymerization of an epoxide. Epoxy has wide application as a matrix for composite materials and as an adhesive that bonds many different types of materials. It is noted for its durability and its chemical resistance.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Engine pressure ratio. The ratio of the turbine discharge total pressure to the compressor inlet total pressure. EPR is normally used as the parameter to determine the amount of thrust an axial-flow turbojet or turbofan engine is producing.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
See engine pressure ratio.
Taught in PP-D Quick reference.
A large resistor in the ground circuit of a heavy-duty aircraft generator through which all of the generator output current flows. The voltage drop across this resistor is used to produce the current in the paralleling circuit that forces the generators to share the electrical load equally.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
Equi-Time Point means a point on the route of flight where the flight time, considering wind, to each of two selected airports is equal.
A condition that exists within a body when the sum of the moments of all of the forces acting on the body is equal to zero. In aerodynamics, equilibrium is when all opposing forces acting on an aircraft are balanced (steady, unaccelerated flight conditions).
A list of items approved by the FAA for installation in a particular aircraft. The list includes the name, part number, weight, and arm of the component. Installation or removal of an item in the equipment list is considered to be a minor alteration.
Taught in GEN-I Quick reference, GEN-C Procedures, GEN-C Concepts, AF-D Procedures, GEN-C Quick reference.
Equivalent airspeed means the calibrated airspeed of an aircraft corrected for adiabatic compressible flow for the particular altitude. Equivalent airspeed is equal to calibrated airspeed in standard atmosphere at sea level.
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.
Guidance: Pilot's Handbook of Aeronautical Knowledge, p. G-11
Equivalent shaft horsepower. A measure of the power produced by a turboprop engine. ESHP takes into consideration both the shaft horsepower delivered to the propeller and the thrust developed at the engine exhaust. Under static conditions, one shaft horsepower is approximately equal to 2.5 pounds of thrust.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
Alcohol made from cereal grains such as corn.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A volatile, highly flammable liquid that may be used to prime the cylinders of an aircraft engine when starting under extremely cold conditions.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A chemical compound added to aviation gasoline to convert some of the deposits left by the tetraethyl lead into lead bromides. These bromides are volatile and will pass out of the engine with the exhaust gases.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
A colorless, poisonous liquid BrCH2CH2Br that is blended with leaded gasoline to help scavenge lead oxides.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A form of alcohol used as a coolant for liquid-cooled engines and as an anti-icing agent.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
A form of alcohol used as a coolant for liquid-cooled aircraft engines. It is also used in automobile engines as a permanent antifreeze.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
ETOPS means extended operations.
ETOPS Significant System means an airplane system, including the propulsion system, the failure or malfunctioning of which could adversely affect the safety of an ETOPS flight, or the continued safe flight and landing of an airplane during an ETOPS diversion. Each ETOPS significant system is either an ETOPS group 1 significant system or an ETOPS group 2 significant system. (1) An ETOPS group 1 Significant System— (i) Has fail-safe characteristics directly linked to the degree of redundancy provided by the number of engines on the airplane. (ii) Is a system, the failure or malfunction of which could result in an IFSD, loss of thrust control, or other power loss. (iii) Contributes significantly to the safety of an ETOPS diversion by providing additional redundancy for any system power source lost as a result of an inoperative engine. (iv) Is essential for prolonged operation of an airplane at engine inoperative altitudes. (2) An ETOPS group 2 significant system is an ETOPS significant system that is not an ETOPS group 1 significant system.
An alloy or solution that has the lowest possible constant melting point.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
An alloy or solution that has the lowest possible melting point. Evacuation (air conditioning servicing procedure). A procedure in servicing vapor-cycle cooling systems. A vacuum pump removes all the air from the system. Evacuation removes all traces of water vapor that could condense out, freeze, and block the system.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
The transformation of a liquid to a gaseous state, such as the change of water to water vapor.
See steam cooling.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
The component in a vapor-cycle cooling system in which heat from the aircraft cabin is absorbed into the refrigerant. As the heat is absorbed, the refrigerant evaporates, or changes from a liquid into a vapor. The function of the evaporator is to lower the cabin air temperature.
Aviation Maintenance Technician Handbook — Airframe, p. G-14
EWIS, as defined by § 25.1701 of this chapter, means electrical wiring interconnection system.
A condition in which a parameter sensed by the EICAS exceeds the limits for which it is programmed.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
The fixed conical fairing centered in the turbine wheel. The exhaust cone straightens the flow and prevents the hot gases from circulating over the rear face of the turbine wheel.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
The temperature of the exhaust gases as they leave the cylinders of a reciprocating engine or the turbine section of a turbine engine.
Taught in PP-D Concepts, PP-D Quick reference, AF-H Quick reference, PP-C Procedures.
The opening at the rear of the exhaust pipe.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
Taught in PP-L Quick reference.
A brake that uses hydraulic fluid inside a synthetic rubber tube around the brake hub to force rectangular blocks of brake-lining material against the rotating brake drum. Friction between the brake drum and the lining material slows the aircraft.
Aviation Maintenance Technician Handbook — Airframe, p. G-15
The change in pressure and velocity of a supersonic flow of air as it passes over a surface which drops away from the flow. As the surface drops away, the air tries to follow it. In changing its direction, the air speeds up to a higher supersonic velocity and its static pressure decreases. There is no change in the total energy as the air passes through an expansion wave, and so there is no sound as there is when air passes through a shock wave.
Aviation Maintenance Technician Handbook — Airframe, p. G-15
The change in pressure and velocity of supersonic air as it passes over a surface that drops away from the flow. As the surface drops away, the air tries to follow it, and in changing its direction, the air speeds up to a higher supersonic speed, and its static pressure decreases. There is no change in the total amount of energy as air passes through an expansion wave.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
The time a pilot can expect to receive clearance beyond a clearance limit.
A pictorial drawing of two or more parts that fit together as an assembly. The view shows the individual parts and their relative position to the other parts before they are assembled.
A change in cabin pressure faster than the lungs can decompress. Lung damage is possible.
A shorthand method of indicating how many times a number, called the base, is multiplied by itself. For example, in the number 43, the 3 is the power or exponent and 4 is the base. That is, 43 is equal to 4 × 4 × 4 = 64.
Extended Operations (ETOPS) means an airplane flight operation, other than an all-cargo operation in an airplane with more than two engines, during which a portion of the flight is conducted beyond a time threshold identified in part 121 or part 135 of this chapter that is determined using an approved one-engine-inoperative cruise speed under standard atmospheric conditions in still air.
Extended over-water operation means— (1) With respect to aircraft other than helicopters, an operation over water at a horizontal distance of more than 50 nautical miles from the nearest shoreline; and (2) With respect to helicopters, an operation over water at a horizontal distance of more than 50 nautical miles from the nearest shoreline and more than 50 nautical miles from an off-shore heliport structure.
Used to extend the line showing the side or edge of a figure for the purpose of placing a dimension to that side or edge.
Taught in GEN-B Procedures.
A form of heat engine in which the fuel releases its energy outside of the engine. This released heat expands air which is used to perform useful work. Steam engines are a popular type of external combustion engine.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
External load means a load that is carried, or extends, outside of the aircraft fuselage.
External-load attaching means means the structural components used to attach an external load to an aircraft, including external-load containers, the backup structure at the attachment points, and any quick-release device used to jettison the external load.
A lubricant that reacts with iron to form iron chlorides, sulfides, or phosphides on the surface of a steel part. These compounds reduce wear and damage to surfaces in heavy rubbing contact. EP lubricants are specially suited for lubricating gear trains.
Aviation Maintenance Technician Handbook — Powerplant, p. G-11
A structural angle formed by passing metal heated to its plastic state through specially shaped dies.
Aviation Maintenance Technician Handbook — Airframe, p. G-15
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.