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.
High-intensity flasher system installed at many large airports. The flashers consist of a series of brilliant blue-white bursts of light flashing in sequence along the approach lights, giving the effect of a ball of light traveling toward the runway.
A form of rotary actuator where the fluid acts on a piston on which a rack of gear teeth is cut. As the piston moves, it rotates a pinion gear which is mated with the teeth cut in the rack.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for Radio Detection and Ranging. The term has since entered the English language as a standard word, radar, losing the capitalization in the process.
Taught in AF-I Concepts, AF-I Quick reference.
The controller provides vectors while monitoring the progress of the flight with radar, guiding the pilot through the descent to the airport/heliport or to a specific runway.
Radar is a method whereby radio waves are transmitted into the air and are then received when they have been reflected by an object in the path of the beam. Range is determined by measuring the time it takes (at the speed of light) for the radio wave to go out to the object and then return to the receiving antenna. The direction of a detected object from a radar site is determined by the position of the rotating antenna when the reflected portion of the radio wave is received.
A weather product derived from the national radar network that graphically displays a summary of radar weather reports.
A report issued by radar stations at 35 minutes after the hour, and special reports as needed. Provides information on the type, intensity, and location of the echo tops of the precipitation.
A directional line radiating outward from a radio facility, usually a VOR. When an aircraft is flying outbound on the 330º from the station.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Taught in PP-A Quick reference.
The load on a bearing perpendicular to the shaft on which the bearing is mounted. Centrifugal loads are radial loads.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
A form of reciprocating engine in which the cylinders radiate out from a small central crankcase. The pistons in the cylinders drive a central crankshaft which in turn drives the propeller.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
A turbine, similar in appearance to a centrifugal compressor rotor. Radial-inflow turbines are used to drive the compressor in reciprocating engine turbochargers and some of the smaller APU turbine engines. Hot gases flow into the turbine from its outside rim, then radially inward through the vanes and out of the turbine at its center.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
The courses oriented from a station.
Electromagnetic waves of certain frequencies produce heat when they are absorbed by the bodies they strike such as x-rays, light rays, and infrared rays.
The continuous emission of energy from the surface of all bodies.
See electromagnetic radiation.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
Taught in GEN-K Concepts.
The symbol √, used to indicate the root of a number.
A term that refers to alternating current (AC) having characteristics such that, if the current is input to antenna, an electromagnetic (EM) field is generated suitable for wireless broadcasting and/or communications.
Taught in AF-I Concepts.
An electronic navigation instrument that combines a magnetic compass with an ADF or VOR. The card of the RMI acts as a gyro-stabilized magnetic compass, and shows the magnetic heading the aircraft is flying.
Taught in AF-I Quick reference.
An electronic altimeter that determines the height of an aircraft above the terrain by measuring the time needed for a pulse of radio-frequency energy to travel from the aircraft to the ground and return.
An electromagnetic (EM) wave with frequency characteristics useful for radio transmission.
Inspection using radiography to locate defects or flaws in airframe structures or engines with little or no disassembly.
Taught in GEN-K Quick reference.
A weather instrument that observes and reports meteorological conditions from the upper atmosphere. This instrument is typically carried into the atmosphere by some form of weather balloon.
Equal to one-half the diameter of a circle.
A process of preparing a hole in sheet metal for flush riveting. A cone-shaped male die forces the edges of the rivet hole into the depression in a female die. Radius dimpling forms a round-edged depression into which the rivet head fits.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
RAIL means runway alignment indicator light system.
See receiver autonomous integrity monitoring.
Air whose pressure has been increased by the forward motion of the aircraft. Ram air pressure is the same as pitot pressure.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
The loss of thrust produced by a turbojet or turbofan engine caused by the increase of velocity of air entering the engine. Ram drag is the difference between gross thrust and net thrust.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
Pressure produced when a moving fluid is stopped.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
The increase in thrust as a result of ram air pressures and density on the front of the engine caused by air velocity.
The speed of an aircraft at which the ram effect caused by the forward movement increases the air pressure at the compressor inlet so that it is the same as that of the ambient air.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
The simplest type of air-breathing reaction engine. Air entering the front of the engine at a high velocity has fuel sprayed into it and ignited. A barrier formed by the incoming air forces the expanding gases to leave through the nozzle at the rear. The energy added by the burning fuel accelerates the air and produces a forward thrust. Ramjet engines are used in some military unmanned aircraft that are initially boosted to a speed high enough for the engine to function.
Aviation Maintenance Technician Handbook — Powerplant, p. G-22
The zero fuel weight plus all of the usable fuel on board.
Direct routes, based on area navigation capability, between waypoints defined in terms of latitude/longitude coordinates, degree-distance fixes, or offsets from established routes/airways at a specified distance and direction.
Colored marks on an instrument dial that identify certain ranges of operation as specified in the aircraft maintenance or flight manual and listed in the appropriate aircraft Type Certificate Data Sheets or Aircraft Specifications. Color coding directs attention to approaching operating difficulties. Airspeed indicators and most pressure and temperature indicators are marked to show the various ranges of operation. These ranges and colors are the most generally used: Red radial line, do not exceed. Green arc, normal operating range. Yellow arc, caution range. Blue radial line, used on airspeed indicators to show best single-engine rate of climb speed. White arc, used on airspeed indicators to show flap operating range.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Taught in AF-H Concepts, AF-H Procedures, AF-H Quick reference, PP-D Concepts, PP-D Quick reference.
Transmitted from the GPS satellite, signals allowing the aircraft’s receiver to determine range (distance) from each satellite.
The almost instantaneous loss of cabin pressure in aircraft with a pressurized cockpit or cabin.
Rated 2 1/2-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter for periods of use no longer than 2 1/2 minutes each after the failure or shutdown of one engine of a multiengine rotorcraft.
Rated 2-minute OEI Power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, for continuation of one flight operation after the failure or shutdown of one engine in multiengine rotorcraft, for up to three periods of use no longer than 2 minutes each in any one flight, and followed by mandatory inspection and prescribed maintenance action.
Rated 30-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, and limited in use to one period of use no longer than 30 minutes after the failure or shutdown of one engine of a multiengine rotorcraft.
Rated 30-second OEI Power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, for continuation of one flight operation after the failure or shutdown of one engine in multiengine rotorcraft, for up to three periods of use no longer than 30 seconds each in any one flight, and followed by mandatory inspection and prescribed maintenance action.
Rated continuous OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, and limited in use to the time required to complete the flight after the failure or shutdown of one engine of a multiengine rotorcraft.
Rated maximum continuous augmented thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically or in flight, in standard atmosphere at a specified altitude, with fluid injection or with the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and approved for unrestricted periods of use.
Rated maximum continuous power, with respect to reciprocating, turbopropeller, and turboshaft engines, means the approved brake horsepower that is developed statically or in flight, in standard atmosphere at a specified altitude, within the engine operating limitations established under part 33, and approved for unrestricted periods of use.
Rated maximum continuous thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically or in flight, in standard atmosphere at a specified altitude, without fluid injection and without the burning of fuel in a separate combustion chamber, within the engine operating limitations established under part 33 of this chapter, and approved for unrestricted periods of use.
Rated takeoff augmented thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically under standard sea level conditions, with fluid injection or with the burning of fuel in a separate combustion chamber, within the engine operating limitations established under part 33 of this chapter, and limited in use to periods of not over 5 minutes for takeoff operation.
Rated takeoff power, with respect to reciprocating, turbopropeller, and turboshaft engine type certification, means the approved brake horsepower that is developed statically under standard sea level conditions, within the engine operating limitations established under part 33, and limited in use to periods of not over 5 minutes for takeoff operation.
Rated takeoff thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically under standard sea level conditions, without fluid injection and without the burning of fuel in a separate combustion chamber, within the engine operating limitations established under part 33 of this chapter, and limited in use to periods of not over 5 minutes for takeoff operation.
Rating means a statement that, as a part of a certificate, sets forth special conditions, privileges, or limitations.
Taught in AF-K Procedures, AF-K Quick reference, PP-F Quick reference.
The comparison of two numbers or quantities.
Taught in GEN-H Procedures, GEN-H Concepts, GEN-H Quick reference, AF-B Concepts, PP-D Quick reference, PP-I Concepts and 8 more.
An analog temperature measuring instrument in which the pointer deflection is proportional to the ratio between the current flowing in an internal reference circuit and that flowing through the temperature-sensing probe.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
See relative bearing.
See relative bearing indicator.
RBN means radio beacon.
RCLM means runway centerline marking.
RCLS means runway centerline light system.
See remote communications outlet.
Radio direction finding.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
The length of the threads on the shell of a spark plug.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
A form of heat engine that produces thrust by heating a mass of air inside the engine and discharging it at a high velocity through a specially shaped nozzle. The amount of thrust is determined by the mass of the air and the amount it is accelerated.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
Wattless power in an AC circuit. It is the power consumed in the inductive and capacitive reactances. Reactive power is expressed in volt-amps reactive (var) or in kilovolt-amps reactive (kvar).
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
The fit of a shaft in a hole in which the hole is drilled undersize and cut with a reamer to the correct diameter. Reamed holes have smooth walls and a consistent diameter.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
Tools made of either carbon tool steel or high-speed steel that are used to smooth and enlarge holes to exact size.
A type of oxygen mask used with a continuous flow oxygen system. Oxygen continuously flows into the bottom of the loose-fitting rebreather bag on the mask. The wearer of the mask exhales into the top of the bag. The first air exhaled contains some oxygen, and this air goes into the bag first. The last air to leave the lungs contains little oxygen, and it is forced out of the bag as the bag is filled with fresh oxygen. Each time the wearer of the mask inhales, the air first exhaled, along with fresh oxygen, is taken into the lungs.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A used engine that has been completely disassembled, inspected, repaired as necessary, and reassembled, tested, and approved in the same manner and to the same tolerances and limits as a new engine, using either new or used parts. However, all parts used must conform to all production drawings, tolerances, and limits for new parts, or be of approved oversize or undersize dimensions for a new engine. According to 14 CFR part 91, section 91.421, a rebuilt engine is considered to have no precious operating history and may be issued a zero-time logbook. Only the engine manufacturer can rebuild an engine and issue a zero-time record.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
A system used to verify the usability of the received GPS signals and warns the pilot of any malfunction in the navigation system. This system is required for IFR-certified GPS units.
The component in a vapor-cycle cooling system that serves as a reservoir for the liquid refrigerant. The receiver-dryer contains a desiccant that absorbs any moisture that may be in the system.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A system that receives and transmits a signal and an indicator.
A type of heat engine that changes the reciprocating (back-and-forth) motion of pistons inside the cylinders into rotary motion of a crank-shaft.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
Taught in PP-A Quick reference, PP-J Quick reference, PP-L Quick reference, PP-H Quick reference, PP-A Procedures, PP-F Quick reference and 1 more.
An altitude depicted on an instrument approach chart with the altitude value neither underscored nor overscored. The depicted value is an advisory value.
A plane surface with four sides whose opposite sides are parallel and whose angles are all right angles.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Taught in GEN-H Quick reference, GEN-H Concepts, GEN-H Procedures.
A condition in AC-electric arc welding in which oxides on the surface of the metal act as a rectifier and prevent electrons flowing from the metal to the electrode during the half cycle when the electrode is positive.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A device for converting alternating current to direct current.
A device that allows electrons to flow in one direction while preventing their flow in the opposite direction. Rectifiers are used to change AC into DC.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
Taught in AF-K Quick reference.
Reduces the vertical separation between flight levels (FL) 290 and 410 from 2,000 feet to 1,000 feet, and makes six additional FLs available for operation. Also see DRVSM.
See carburizing flame.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A number, usually 100 or 1,000, by which a moment is divided to produce a smaller number that is less likely to cause mathematical errors when computing the center of gravity.
Taught in GEN-C Procedures, GEN-C Quick reference.
A thin, leaf-type valve mounted in the valve plate of an air conditioning compressor to control the flow of refrigerant gases into and out of the compressor cylinders.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
The circle depicted in the plan view of an IAP chart that typically has a 10 NM radius, within which chart the elements are drawn to scale.
(GAMA) An imaginary vertical plane from which all horizontal distances are measured for balance purposes.
Reference landing speed means the speed of the airplane, in a specified landing configuration, at the point where it descends through the 50 foot height in the determination of the landing distance.
Flight regime in which flight at a higher airspeed requires a lower power setting and a lower airspeed requires a higher power setting in order to maintain altitude.
The “regions of normal and reversed command” refers to the relationship between speed and the power required to maintain or change that speed in flight.
The British name for an afterburner. See afterburner.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
The amount of pressure that must be exerted on a liquid to keep it from vaporizing. Reid vapor pressure is measured at 100 ºF.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
REIL means runway end identification lights.
See runway end identifier lights.
Guidance: Pilot's Handbook of Aeronautical Knowledge, p. G-25
A narrow strip of woven fabric material placed over the fabric as it is being attached to the aircraft structure with rib lacing cord. This tape carries a large amount of the load and prevents the fabric tearing at the stitches.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A finishing material used to restore resilience to an old dope film. Rejuvenator contains strong solvents to open the dried-out film and plasticizers to restore resilience to the old dope.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
The angular difference between the aircraft heading and the direction to the station, measured clockwise from the nose of the aircraft.
Also known as the fixed-card ADF, zero is always indicated at the top of the instrument and the needle indicates the relative bearing to the station.
The ratio of the amount of water vapor actually present in the atmosphere to the amount that would be present if the air were saturated at the prevailing temperature and pressure.
The ratio of the existing amount of water vapor in the air at a given temperature to the maximum amount that could exist at that temperature; usually expressed in percent.
The direction the wind strikes an airfoil.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Direction of the airflow produced by an object moving through the air. The relative wind for an airplane in flight flows in a direction parallel with and opposite to the direction of flight; therefore, the actual flight path of the airplane determines the direction of the relative wind.
An electrical component which uses a small amount of current flowing through a coil to produce a magnetic pull to close a set of contacts through which a large amount of current can flow. The core in a relay coil is fixed.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Taught in GEN-A Quick reference.
The ability of an aircraft engine to perform its designed functions under widely varying operating conditions.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
A hole drilled at the point at which two bend lines meet in a piece of sheet metal. This hole spreads the stresses caused by the bends and prevents the metal cracking.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
A pressure-control valve that relieves any pressure over the amount for which it is set. They are damage-preventing units used in both hydraulic and pneumatic systems. In an aircraft hydraulic system, pressure relief valves prevent damaging high pressures that could be caused by a malfunctioning pressure regulator, or by thermal expansion of fluid trapped in portions of the system.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Taught in PP-G Procedures, PP-G Concepts, AF-F Concepts, AF-O Concepts, GEN-A Concepts, PP-G Quick reference.
The leftover number in the process of division.
Taught in AF-A Procedures, PP-B Concepts.
An unmanned communications facility that is remotely controlled by air traffic personnel.
The restoration of an aircraft component to its previous state.
A maintenance procedure in which a damaged component is restored to its original condition, or at least to a condition that allows it to fulfill its design function.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Used throughout the curriculum.
A maintenance facility certificated under 14 CFR part 145 to perform maintenance functions.
Taught in AF-I Concepts.
Reporting point means a geographical location in relation to which the position of an aircraft is reported.
A specified level of accuracy defined by a lateral area of confined airspace in which an RNP-certified aircraft operates.
The fuel that remains trapped in the system after draining the fuel from the aircraft with the aircraft in level flight attitude. The weight of this residual fuel is counted as part of the empty weight of the aircraft.
Taught in PP-A Concepts.
A form of magnetic particle inspection for small steel parts that have a high degree of retentivity. The part is magnetized, removed, and inspected away from the magnetizing machine.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
The magnetism that remains in the field frame of a generator when no current is flowing in the field coils.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
Taught in PP-F Concepts.
The voltage produced in a generator armature when the armature is rotated in the residual magnetism.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
The opposition a device or material offers to the flow or current.
Taught in GEN-A Procedures, AF-I Concepts, GEN-A Concepts, GEN-A Hands-on, PP-D Procedures, GEN-A Quick reference and 19 more.
A shielded spark plug with a resistor between the ignition lead terminal and the center electrode. The resistor stops the flow of secondary current when its voltage drops to a specified value. The resistor prevents capacitive afterfiring.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
The increase in amplitude of vibrations of hypotenuse an electric or mechanical system exposed to a periodic force whose frequency is equal or very close to the natural frequency of the system.
Taught in AF-E Concepts, AF-E Quick reference.
Restricted area. A restricted area is airspace designated under Part 73 within which the flight of aircraft, while not wholly prohibited, is subject to restriction.
Airspace designated under 14 CFR part 73 within which the flight of aircraft, while not wholly prohibited, is subject to restriction.
Guidance: Pilot's Handbook of Aeronautical Knowledge, p. G-25
A fluid power system component that controls the rate of actuator movement by restricting the flow of fluid into or out of the actuator.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
Airflow from rotation that is modified by induced flow.
A set of breaker points in certain aircraft magnetos that are used to provide a late (retarded) spark for starting the engine.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
The timing of the firing of the spark plugs used to start a reciprocating engine. The sparks for starting occur later in terms of crankshaft rotation than those used for normal operation. Retarding the sparks prevent the engine from kicking back when it is being started.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
Dope thinner that contains certain additives that slow its rate of evaporation enough to prevent dope blushing.
Aviation Maintenance Technician Handbook — Airframe, p. G-28
The ability of a material to hold its magnetism after the magnetizing field has been removed.
The ability of a magnetizable material to retain the alignment of the magnetic domains after the magnetizing force has been removed. Hard steel normally has a high retentivity, while soft iron and electrical steel both have very low retentivity.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
The replacement of the tread rubber on an aircraft tire.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
The blade on a helicopter rotor whose tip is moving in the direction opposite to that in which the helicopter is moving.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
Any blade, located in a semicircular part of the rotor disk, in which the blade direction is opposite to the direction of flight.
Taught in AF-N Concepts, AF-N Quick reference.
The stall of a helicopter rotor disc that occurs near the tip of the retreating blade. A retreating blade stall occurs when the flight airspeed is high and the retreating blade airspeed is low. This results in a high angle of attack, causing the stall.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A stall that begins at or near the tip of a blade in a helicopter because of the high angles of attack required to compensate for dissymmetry of lift.
The portion of a fluid power system through which the fluid is returned to the reservoir.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A type of combustor in which the air from the compressor enters the combustor outer case and reverses its direction as it flows into the inner liner. It again reverses its direction as it flows into the inner liner. It again reverses its direction before it flows through the turbine. Reverse-flow combustors are used where engine length is critical.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
DC-electric arc welding in which the electrode is positive with respect to the work.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
The VOR needle appearing to indicate the reverse of normal operation.
Radio frequency.
Electromagnetic energy with a frequency high enough to radiate from any conductor through which it is flowing.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
RFFS means rescue and firefighting services.
A variable resistor used to vary the amount of current flowing in a circuit.
The photosensitive pigments that initiate the visual response in the rods of the eye.
A series of circumferential grooves cut into the tread of a tire. This tread pattern provides superior traction and directional stability on hard-surfaced runways.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
The direction in a piece of honeycomb material that is parallel to the length of the strips of material that make up the core.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A condition in which the fire in a gas turbine engine goes out because the air/fuel mixture ratio is too rich to sustain combustion.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23
A air/fuel mixture that contains less than 15 parts of air to 1 part of fuel, by weight.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
Taught in PP-H Hands-on.
A hand file with its teeth formed on a curved surface that resembles a spoon.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
The final adjustment and alignment of an aircraft and its flight control system that provides the proper aerodynamic characteristics.
Taught in AF-C Quick reference, AF-C Concepts, AF-C Procedures, AF-N Quick reference, PP-I Quick reference, AF-G Procedures and 8 more.
Aluminum alloy tubing used to house electrical wires in areas where they are subject to mechanical damage.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A rotor system permitting blades to feather, but not flap or hunt.
Taught in AF-N Quick reference.
The characteristic of a gyroscope that prevents its axis of rotation tilting as the Earth rotates.
Taught in AF-K Hands-on.
The characteristic of a gyroscope that prevents its axis of rotation tilting as the earth rotates. This characteristic is used for attitude gyro instruments.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
The principle that a wheel with a heavily weighted rim spinning rapidly will remain in a fixed position in the plane in which it is spinning.
A rough ice that forms on aircraft flying through visible moisture, such as a cloud, when the temperature is below freezing. Rime ice disturbs the smooth airflow as well as adding weight.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
Rough, milky, opaque ice formed by the instantaneous freezing of small supercooled water droplets.
The future impact of a hazard that is not eliminated or controlled.
Used throughout the curriculum.
There are four fundamental risk elements in aviation: the pilot, the aircraft, the environment, and the type of operation that comprise any given aviation situation.
Taught in GEN-G Concepts, AF-E Concepts, AF-K Concepts, GEN-D Concepts, GEN-F Concepts, GEN-F Quick reference and 1 more.
The part of the decision-making process which relies on situational awareness, problem recognition, and good judgment to reduce risks associated with each flight.
Taught in AF-K Concepts, GEN-B Concepts, GEN-D Concepts, GEN-F Concepts, GEN-G Concepts, GEN-H Concepts and 5 more.
Special cutting pliers that resemble diagonal cutters except that the jaws are ground in such a way that they cut the rivet shank, or stem, off square.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A tool used to drive aircraft solid rivets. It is a piece of hardened steel with a recess the shape of the rivet head in one end. The other end fits into the rivet gun.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
Taught in AF-A Hands-on.
Radio magnetic indicator.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
See radio magnetic indicator.
Taught in AF-I Quick reference.
Root mean square. A dimension that is the square root of the average of an infinite number of varying values. An rms dimension is used to indicate the allowable surface roughness of a reciprocating engine cylinder wall.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
RNAV means area navigation.
See area navigation.
Guidance: Pilot's Handbook of Aeronautical Knowledge, p. G-26
Taught in AF-I Quick reference.
See required navigation performance.
A pivoted arm on the cylinder head of a reciprocating engine. The pushrod forces one end of the rocker arm up, and as the other end moves down, it forces the poppet valve off of its seat.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
The enclosed part of a reciprocating engine cylinder that houses the rocker arm and valve mechanism.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
Rocket means an aircraft propelled by ejected expanding gases generated in the engine from self-contained propellants and not dependent on the intake of outside substances. It includes any part which becomes separated during the operation.
A form of reaction engine whose fuel and oxidizer contain all of the oxygen needed for the release of heat energy. The released heat expands the gases which are ejected at a high velocity from a nozzle at the rear of the rocket. Because rocket engines carry their own oxygen, they can operate in outer space where there is no atmosphere.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
A shaft used in the mechanism of a pressure measuring instrument to change the direction of movement by 90º and to amplify the amount of movement.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
Rotation of an aircraft about its longitudinal axis.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A number that when multiplied by itself a specified number of times will produce a given number. The two most commonly used roots are the square root and the cube root.
Taught in GEN-H Procedures, AF-N Concepts, GEN-A Hands-on, GEN-H Concepts, GEN-J Concepts, PP-B Concepts and 1 more.
A positive-displacement air pump that uses two intermeshing figure-8-shaped rotors to move the air.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A method of securing one metal tube inside another by welding. Small holes are drilled in the outer tube and the inner tube is welded to it around the circumference of the holes.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A fluid power actuator whose output is rotational. A hydraulic motor is a rotary actuator.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A form of reciprocating engine used in some early aircraft. The crankshaft is rigidly attached to the airframe, and the propeller, crankcase, and cylinders all revolve as a unit.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
A form of internal combustion engine in which a rounded, triangular-shaped rotor with sliding seals at the apexes forms the combustion space inside an hourglass-shaped chamber. Expanding gases from the burning air/fuel mixture push the rotor around and turn a geared drive shaft in its center. The RC engine was conceived in Germany by Felix Wankel in 1955.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
The component of relative wind produced by the rotation of the rotor blades.
A complete system of rotating airfoils creating lift for a helicopter.
Taught in AF-N Quick reference, AF-N Concepts, AF-N Procedures, AF-H Concepts, GEN-I Quick reference, PP-B Concepts and 1 more.
A device used to stop the rotor blades during shutdown.
See disk area.
The force produced by the rotor, comprised of rotor lift and rotor drag.
Rotorcraft means a heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors.
Taught in AF-N Quick reference, AF-N Concepts, AF-J Concepts, AF-N Procedures, AF-G Concepts, GEN-G Procedures and 3 more.
Rotorcraft-load combination means the combination of a rotorcraft and an external-load, including the external-load attaching means. Rotorcraft-load combinations are designated as Class A, Class B, Class C, and Class D, as follows: (1) Class A rotorcraft-load combination means one in which the external load cannot move freely, cannot be jettisoned, and does not extend below the landing gear. (2) Class B rotorcraft-load combination means one in which the external load is jettisonable and is lifted free of land or water during the rotorcraft operation. (3) Class C rotorcraft-load combination means one in which the external load is jettisonable and remains in contact with land or water during the rotorcraft operation. (4) Class D rotorcraft-load combination means one in which the external-load is other than a Class A, B, or C and has been specifically approved by the Administrator for that operation.
Route segment is a portion of a route bounded on each end by a fix or navigation aid (NAVAID).
A visual examination or check of an item in which no disassembly is required.
A lightly twisted roll or strand of fibers.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
Revolutions per minute.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
Revolutions per minute. A measure of rotational speed. One rpm is one revolution made in one minute.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
Taught in GEN-J Procedures, PP-M Procedures, PP-F Procedures, PP-M Concepts, GEN-J Concepts, PP-A Procedures and 10 more.
RR means low or medium frequency radio range station.
See receiver-transmitter.
The movable primary control surface mounted on the trailing edge of the vertical fin of an airplane. Movement of the rudder rotates the airplane about its vertical axis.
A pair of control surfaces on the tail of an aircraft arranged in the form of a V. These surfaces, when moved together by the control wheel, serve as elevators, and when moved differentially by the rudder pedals, serve as a rudder.
The two movable surfaces on a V-tail empennage. When these two surfaces are moved together with the in-and-out movement of the control yoke, they act as elevators, and when they are moved differentially with the rudder pedals, they act as the rudder.
Aviation Maintenance Technician Handbook — Airframe, p. G-29
A time of controlled operation of a new or freshly overhauled engine that allows the moving parts to wear together.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
Taught in PP-K Concepts.
A procedure in which an aircraft engine is operated on the ground to determine its condition and performance.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
Taught in AF-N Concepts, PP-H Concepts.
A measure of the amount a shaft, flange, or disc is bent or fails to run true. Runout is normally measured with a dial indicator.
Aviation Maintenance Technician Handbook — Powerplant, p. G-24
Taught in GEN-E Procedures.
Runway lighting which consists of flush centerline lights spaced at 50-foot intervals beginning 75 feet from the landing threshold.
A component of the runway lighting system that is used to outline the edges of runways at night or during low visibility conditions. These lights are classified according to the intensity they are capable of producing.
A pair of synchronized flashing lights, located laterally on each side of the runway threshold, providing rapid and positive identification of the approach end of a runway.
The visibility determined for a particular runway by a transmissometer.
The instrumentally derived horizontal distance a pilot should be able to see down the runway from the approach end, based on either the sighting of high-intensity runway lights, or the visual contrast of other objects.
RVR means runway visual range as measured in the touchdown zone area.
See runway visual range.
Guidance: Pilot's Handbook of Aeronautical Knowledge, p. G-26
See runway visibility value.
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.