Alpha   Bismillah   Charlie  Delta   Echo
  Foxtrot   Golf    Hotel    insaallah  Juliett   Kilo   Lima   Mike   November Oscar   Piaggio   Quebec   Romeo   Sierra   Turks    Uniform   Victory   Water   X-ray   Yankee   Zulu    Main Page

team img 1

RABBET

rabbet A groove cut into the edge or face of a board so that another board or panel can be fitted into it. Allows a T- or L-shaped assembly to be constructed.

rabbet plane A woodworking tool used to create rabbets in a surface.

race A grooved, hardened, and polished steel surface on which a bearing is supported.

racetrack procedure (ICAO) A procedure designed to enable the aircraft to reduce altitude during the initial approach segment and/or establish the aircraft inbound when the entry into a reversal procedure is not practical.

rack A straight piece of metal that has teeth cut into one side.

rack and pinion A set of gears arranged in such a way that a rotary motion of the pinion gear is changed into linear motion of the rack.

rack and pinion actuator A rotary actuator in which the fluid acts on the rack of gear teeth cut on a piston. As the piston moves it rotates a mating pinion gear.

radar A device that, by measuring the time interval between transmission and reception of radio pulses and correlating the angular orientation of the radiated antenna beam or beams in azimuth and/or elevation, provides information on range, azimuth, and/or elevation of objects in the path of the transmitted pulses.

a. Primary Radar A radar system in which a minute portion of a radio pulse transmitted from a site is reflected by an object and then received back at that site for processing and display at an air traffic control facility.

b. Secondary Radar/Radar Beacon (Air Traffic Control Radar Beacon System (ATCRBS)) A radar system in which the object to be detected is fitted with cooperative equipment in the form of a radio receiver/transmitter (transponder). Radar pulses transmitted from the searching transmitter/receiver (interrogator) site are received in the cooperative equipment and used to trigger a distinctive transmission from the transponder. This reply transmission, rather than a reflected signal, is then received back at the transmitter/receiver site for processing and display at an air traffic control facility.

radar advisory Information or advice provided to pilots based on radar observations.

radar altimeter Aircraft equipment that makes use of the reflection of radio waves from the ground to determine the height of the aircraft above the surface.

radar altitude Distance from the ground determined by radar altimeter, which makes use of the reflection of radio waves from the ground.

radar approach An instrument approach procedure that utilizes Precision Approach Radar (PAR) or Airport Surveillance Radar (ASR).

radar approach control facility A terminal ATC facility that uses radar and nonradar capabilities to provide approach control services to aircraft arriving, departing, or transiting airspace controlled by the facility.

a. Provides radar ATC services to aircraft operating in the vicinity of one or more civil and/or military airports in a terminal area. The facility can provide services of a ground controlled approach (GCA); i.e., ASR and PAR approaches. A radar approach control facility can be operated by FAA, USAF, US Army, USN, USMC, or jointly by FAA and a military service.

b. Specific facility nomenclatures are used for administrative purposes only and are related to the physical location of the facility and the operating service generally as follows:

1. Army Radar Approach Control (ARAC) (Army).

2. Radar Air Traffic Control Facility (RATCF) (Navy/ FAA).

3. Radar Approach Control (RAPCON) (Air Force/ FAA).

4. Terminal Radar Approach Control (TRACON) (FAA).

5. Air Traffic Control Tower (ATCT) (FAA). (Only those towers delegated approach control authority.)

radar beacon transponder An electronic device that receives an interrogation or transmission from ground radar and responds with a coded transmission that appears on the traffic controller s radar scope.

radar beam A narrow beam of electromagnetic radiation used in radar units to determine distance, height, size, and composition of desired target items.

radar contact Term used by ATC to advise a pilot that the aircraft is identified on radar.

radar echo The returning radar signal that is reflected from an object.

radar identified aircraft An aircraft, the position of which has been correlated with an observed target or symbol on the radar display.

radar monitoring The radar flight-following of aircraft, whose primary navigation is being performed by the pilot, to observe and note deviations from its authorized flight path, airway, or route. When being applied specifically to radar monitoring of instrument approaches; i.e., with precision approach radar (PAR) or radar monitoring of simultaneous ILS/MLS approaches, it includes advice and instructions whenever an aircraft nears or exceeds the prescribed PAR safety limit or simultaneous ILS/ MLS no transgression zone.

radar navigational guidance Vectoring aircraft to provide course guidance.

radar point out An action taken by a controller to transfer the radar identification of an aircraft to another controller if the aircraft will or may enter the airspace or protected airspace of another controller and radio communications will not be transferred.

radar required A term displayed on charts and approach plates and included in FDC Notams to alert pilots that segments of either an instrument approach procedure or a route are not navigable because of either the absence or unusability of a NAVAID. The pilot can expect to be provided radar navigational guidance while transiting segments labeled with this term.

radar route A flight path or route over which an aircraft is vectored. Navigational guidance and altitude assignments are provided by ATC.

radar separation Radar spacing of aircraft in accordance with established minima.

radar service A term that encompasses one or more of the following services based on the use of radar that can be provided by a controller to a pilot of a radar identified aircraft.

a. Radar Monitoring The radar flight-following of aircraft, whose primary navigation is being performed by the pilot, to observe and note deviations from its authorized flight path, airway, or route. When being applied specifically to radar monitoring of instrument approaches; i.e., with precision approach radar (PAR) or radar monitoring of simultaneous ILS/ MLS approaches, it includes advice and instructions whenever an aircraft nears or exceeds the prescribed PAR safety limit or simultaneous ILS/ MLS no transgression zone.

b. Radar Navigational Guidance Vectoring aircraft to provide course guidance.

c. Radar Separation Radar spacing of aircraft in accordance with established minima.

radar service [ICAO] Term used to indicate a service provided directly by means of radar.

a. Monitoring The use of radar for the purpose of providing aircraft with information and advice relative to significant deviations from nominal flight path.

b. Separation The separation used when aircraft position information is derived from radar sources.

radar service terminated Used by ATC to inform a pilot that he will no longer be provided any of the services that could be received while in radar contact. Radar service is automatically terminated, and the pilot is not advised in the following cases:

a. An aircraft cancels its IFR flight plan, except within Class B airspace, Class C airspace, a TRSA, or where Basic Radar service is provided.

b. An aircraft conducting an instrument, visual, or contact approach has landed or has been instructed to change to advisory frequency.

c. An arriving VFR aircraft, receiving radar service to a tower-controlled airport within Class B airspace, Class C airspace, a TRSA, or where sequencing service is provided, has landed; or to all other airports, is instructed to change to tower or advisory frequency.

d. An aircraft completes a radar approach.

radar summary chart A weather product derived from the national radar network that graphically displays a summary of radar weather reports.

radar surveillance The radar observation of a given geographical area for the purpose of performing some radar function.

radar traffic advisories Advisories issued to alert pilots to known or observed radar traffic that can affect the intended route of flight of their aircraft.

radar traffic information service Advisories issued to alert pilots to observation of radar identified and nonidentified aircraft targets on an ATC radar display that may be in such proximity to the position or intended route of flight of their aircraft as to warrant their attention.

radar vector A heading issued by a radar controller to the pilot of an aircraft to provide navigational guidance.

radar vectoring [ICAO] Provision of navigational guidance to aircraft in the form of specific headings based on the use of radar.

radar weather echo intensity levels Existing radar systems cannot detect turbulence. However, there is a direct correlation between the degree of turbulence and other weather features associated with thunderstorms and the radar weather echo intensity. The National Weather Service has categorized radar weather echo intensity for precipitation into six levels. These levels are sometimes expressed during communications as VIP LEVEL 1 through 6 (derived from the component of the radar that produces the information - Video Integrator and Processor). The following list gives the VIP LEVELS in relation to the precipitation intensity within a thunderstorm:

Level 1. WEAK

Level 2. MODERATE

Level 3. STRONG

Level 4. VERY STRONG

Level 5. INTENSE

Level 6. EXTREME

radarsonde observation An upper air observation used to determine winds, and other meteorological data, by tracking the range, elevation, and azimuth of a radar target carried aloft, usually by a balloon.

radial A navigational signal generated by a VOR or VORTAC. Each VOR station has 360 radials. The radials are assigned numbers that pertain to their position around the magnetic compass card and are considered being drawn away from the VOR station in a particular magnetic direction.

radial engine A reciprocating aircraft engine in which all of the cylinders are arranged radially, or spoke-like, around a small crankcase.

radial inflow turbine A turbine wheel that receives its gases at the blade tips and guides the air inward and outward to the exhaust duct. It looks similar to a radial outflow compressor and is used extensively in APUs.

radial lead An electrical component lead that protrudes from the outside of a component.

radial outflow compressor An impeller-shaped device that receives air at its center and slings it outward at high velocity into a diffuser for increased pressure.

radial ply tire A tire in which layers of metal or synthetic casing plies are constructed at right angles to the tread. The plies are folded around the wire beads and back against the tire sidewall, completely encompassing the tire body.

radial velocity Motion toward or away from Doppler RADAR.

radian A unit of angular measurement equal to the angle between two radii, separated by an arc equal to the length of the radius. Radians are used in the measurement of angular velocity.

radiant energy Energy due to any form of electromagnetic radiation, for instance, from the sun.

radiant heat The transfer of heat energy from a heat source to the surrounding air. Rooms that have heated water tubing embedded in the floor use radiant heat.

radiation Energy radiated in the form of electromagnetic waves.

radiation The emission of energy by a medium and transferred, either through free space or another medium, in the form of electromagnetic waves.

radiation fog Fog characteristically resulting when radiational cooling of the Earth s surface lowers the air temperature near the ground to or below its initial dewpoint on calm, clear nights.

radiation sensing detector A fire detection system that utilizes heat-sensitive units to complete an electrical circuit when the temperature rises to a preset value.

radiation shield An insulation blanket made with layers of aluminum foil used around turbine engines to prevent heat radiating from the engine into the structure.

radical sign The mathematical symbol √ placed before a quantity to show its root is to be extracted.

radio 1. A device used for communication. 2. Used to refer to a flight service station; e.g., Seattle Radio is used to call Seattle FSS.

radio altimeter (RA) A device that measures the height of an aircraft above the terrain by means of the transmissions of a continuous wave, constant amplitude, frequency modulated signal. The difference in the frequency of the reflected signals at any time is read on the RA indicator in feet above the ground.

radio beacon An L/MF or UHF radio beacon transmitting nondirectional signals whereby the pilot of an aircraft equipped with direction finding equipment can determine his bearing to or from the radio beacon and home on or track to or from the station. When the radio beacon is installed in conjunction with the Instrument Landing System marker, it is normally referred to as a compass locator.

radio control Operating a unit or device by means of radio transmissions.

radio detection and ranging (Radar) A device that, by measuring the time interval between transmission and reception of radio pulses and correlating the angular orientation of the radiated antenna beam or beams in azimuth and/or elevation, provides information on range, azimuth, and/or elevation of objects in the path of the transmitted pulses.

radio direction finding A method of determining the direction from which signals are received. When an aircraft is within reception range of a radio station, a directional antenna provides a means of fixing a bearing from the station to the aircraft. The bearings from two or more receivers are plotted on a chart to determine the position of the aircraft with reasonable accuracy.

radio frequency The electromagnetic waves that radiate from the antenna of a radio transmitter. The frequency is higher than the audible frequency range and below the frequency range of heat and light.

radio frequency energy Electromagnetic energy used for communication. Generally in the frequency range of 3 kilohertz to 300 gigahertz.

Radio Magnetic Indicator (RMI) A movable-card instrument on which the card automatically rotates to reflect the aircraft s magnetic heading. Two needles display the relative bearing to ADF and VOR stations.

radio marker beacon A low-powered, single-frequency radio transmitter used to designate specific navigational points. Marker beacon receivers receive the signal only when flying directly over the radio marker beacon.

radio transmitter An electronic device that transmits electromagnetic waves for the purpose of communicating with associated receiver(s).

radioactivity The property possessed by some elements or isotopes of emitting electrons or alpha particles as their atomic nuclei disintegrate.

radio-frequency cable A transmission line in which the center conductor is surrounded by an insulator and a braided outer conductor. All of this is enclosed in a weatherproof outer insulator.

radio-frequency interference (RFI) Undesired electromagnetic radiation that interferes with radio communication. Often the result of improperly filtered radio transmitters and other electronic equipment.

radio-frequency spectrum The range of frequencies used for radio communication. Commonly used bands are:

BAND FREQUENCY RANGE

Very Low Frequency (VLF) 3-30 kHz

Low Frequency (LF) 30-300 kHz

Medium Frequency (MF) 300-3,000 kHz

High Frequency (HF) 3-30 MHz

Very High Frequency (VHF) 30-300 MHz

Ultra High Frequency (UHF) 300-3,000 MHz

Super High Frequency 3-30 GHz

Extremely High Frequency (EHF) 30-300 GHz

radiography The system of nondestructive inspection using X-rays or gamma rays to determine the condition of a part without disassembly.

radiosonde A balloon-borne instrument for measuring pressure, temperature, and humidity aloft.

radiosonde observation a sounding made by the instrument. If the balloon is tracked, winds can also be determined.

radium A radioactive element with a symbol of Ra and an atomic number of 88.

radium poisoning A poisoning associated with the handling of luminous materials used for marking the dials on some older aircraft instruments.

radius 1. The distance from the center of a circle or sphere to its outer circumference; one half the diameter of a circle. 2. Also, the radial part of an object.

radius bar The part of the cornice brake top leaf that has an accurately ground radius at its edge for bending sheet metal. It is used to obtain a bend radius appropriate to the alloy and thickness of a material.

radius block A metal block around which sheet metal is bent to obtain a specific bend radius.

radius dimpling A method of preparing thin sheet metal in which a cone-shaped male die is forced into the recess of a female die with either a hammer or a pneumatic rivet gun. The material can be riveted with flush rivets after the dimpling process is complete.

radius gauge A precision gauge with an accurately cut inside and outside radii, used to measure the radius of a bend.

radius of turn The amount of horizontal distance an aircraft uses to complete a turn.

radome The protective covering of a radar antenna. A radome is constructed of lightweight honeycomb core material electrically transparent so it will not interfere with the transmitted and received pulses of electrical energy.

rag wing A common slang term for a fabric covered airplane.

rain Precipitation with water drops larger than drizzle and that fall in relatively straight, although not necessarily vertical, paths as compared to drizzle that falls in irregular paths.

rain bands Streaks of rain that spiral into a storm, lines of convergence associated with CB s (cumulonimbus) clouds and shower activity.

rain gauge An instrument used to measure the amount of rain that has fallen in a given locale.

rain shadow The drier downwind side of a mountain.

rain shower Precipitation in the form of rain from a cumuliform cloud; characterized by sudden onset and cessation, rapid change of intensity, and usually by rapid change in the appearance of the sky.

ram air pressure The air pressure caused by the forward motion of an aircraft. Ram air pressure is slightly above ambient air pressure.

ram air temperature rise The increase in temperature caused by the ram compression of the air as an aircraft passes through the air at a high rate of speed. The rate of temperature increase is proportional to the square of the speed of the aircraft.

ram pressure rise The pressure rise in the inlet due to the forward speed of the aircraft.

ram ratio The ratio of ram pressure to ambient pressure in a jet engine.

ram temperature rise The inlet temperature rise due to inlet ram pressure rise.

ramp The apron or paved surface around a hangar used for parking aircraft.

ramp and soak In composites, a curing process in which the temperature is slowly raised at a given rate to the final cure temperature and held for a specific amount of time.

After that time, the temperature is slowly lowered to room temperature. For example, if the final cure temperature for a part is 250 F, the temperature would be ramped up to 250 at a rate of 8 per minute. Once it reaches 250 , the temperature is held there for 1 hour and 30 minutes, and then the temperature is lowered to 80 at a rate of 5 per minute. This process is typically done by using a temperature controller found on hot patch bonding equipment.

ramp weight The total weight of the aircraft while on the ramp. It differs from takeoff weight by the weight of the fuel that will be consumed in taxiing to the point of takeoff.

random altitude An altitude inappropriate for direction of flight and/or not in accordance with FAA Order 7110.65, paragraph 4-5-1.

random route Any route not established or charted/ published or not otherwise available to all users.

range-height indicator (RHI) scope A radar display with height as the vertical axis and range as the horizontal axis. A vertical cross section of the cloud masses in a particular azimuth can be determined.

Rankine Temperature The absolute temperature scale using degrees Fahrenheit with minus 460 F as absolute zero. It is used in many engine performance calculations.

rapid decompression The almost instantaneous loss of cabin pressure in aircraft with a pressurized cockpit or cabin.

rapid exit taxiway (ICAO) A taxiway connected to a runway at an acute angle and designed to allow landing airplanes to turn off at higher speeds than are achieved on other exit taxiways thereby minimizing runway occupancy times.

rarefied air Of or pertaining to less air. Often used to describe the Earth s upper atmosphere.

rasp A coarse file with raised cutting points used for scraping soft materials such as wood or plastic.

ratchet A mechanism that consists of a toothed wheel and a bar, or pawl, which allows the wheel to rotate in one direction but prevents its backward motion.

ratchet coupling A toothed wheel into which a pawl drops so that motion can be imparted to the wheel in only one direction.

ratchet handle A handle with a ratchet coupling used to turn socket-type wrenches. A ratcheting mechanism in the handle allows the socket to be turned in one direction while the handle is moved with a back-and-forth movement. By reversing the catch in the ratchet body, the same back-and-forth movement of the handle will rotate the socket in the opposite direction.

rate gyro A device used to measure the rate of an aircraft s rotation about its vertical axis through 360 . A rate gyro is not affected by the roll or pitch of the aircraft but aligns itself with the fore and aft line.

rate of burning The time required for a specific amount of fuel-air mixture to burn or to release its heat energy.

rate of climb The rate, measured in feet per minute, at which vertical motion occurs.

rate of turn The change of heading per unit of time. For example, 180 per minute, or 3 per second.

rate of yaw The rate, in degrees per second, at which an aircraft rotates about its vertical axis.

rate signal A signal proportional to a rate of change.

rated 2 1/2-minute OEI (one engine inoperative) 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 FAR Part 33, and limited in use to a period of not more than 2 minutes after the failure of one engine of a multiengine rotorcraft.

rated 2-minute OEI (one engine inoperative) 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 FAR part 33, for continued one-flight operation after the failure of one engine in multiengine rotorcraft, limited 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 (one engine inoperative) 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 FAR Part 33, and limited in use to a period of not more than 30 minutes after the failure of one engine of a multiengine rotorcraft.

rated 30-second OEI (one engine inoperative) 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 FAR part 33, for continued one-flight operation after the failure of one engine in multiengine rotorcraft, limited 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 (one engine inoperative) 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 FAR Part 33, and limited in use to the time required to complete the flight after the failure of one engine of a multiengine rotorcraft.

rated horsepower The maximum horsepower an engine is approved to produce under a given set of circumstances.

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.

rated thrust A manufacturer s guaranteed thrust as specified on the Type Certificate.

rate-of-climb indicator A rate of air pressure change device that indicates the rate at which an airplane is climbing or descending in feet per minute. Also referred to as a vertical speed indicator.

rate-of-temperature rise indicator A thermocouple fire detection system that depends on a rapid rate of temperature rise in order to operate. It will not indicate an overheat condition that has developed slowly.

rating A statement that, as a part of a certificate, sets forth special conditions, privileges, or limitations.

ratio The relationship between one number and another number expressed as a fraction. A proportion.

ratiometer indicator A DC remote-indicating system whose pointer movement is determined by the ratio of current-flow between two resistors or portions of a special variable resistor.

rationalization A defense mechanism that students employ when they cannot accept the real reason for their behavior. This permits them to substitute excuses for reasons; moreover, they can make those excuses plausible and acceptable to themselves. A subconscious technique for justifying actions that otherwise would be unacceptable.

rattail file A steel tool that has a circular cross section with hardened ridged surfaces, used in smoothing, grinding, or boring. Also referred to as a round file.

rawhide mallet A mallet made of rawhide wound into a tight cylinder used to form sheet metal without scratching it.

RC circuit A circuit containing both resistance and capacitance.

RC time constant The time required to charge a capacitor to 63.2% of its full-charge state through a given resistance.

reach The length of the shell thread of a spark plug. For 18 mm spark plugs, long-reach plugs are threaded for 13/16 and short-reach plugs for .

reactance The opposition to the flow of AC made by an induction coil or a capacitor. Reactance is expressed in ohms.

reaction A response to a stimulus or force. An event or sequence of events caused by another action.

reaction engine A jet engine that receives thrust only from the reaction caused by hot gases being expelled.

reaction formation A defense mechanism where students protect themselves from dangerous desires by not only repressing them, but by actually developing conscious attitudes and behavior patterns that are just the

opposite. A student can develop a who-cares-what-other-people-think attitude to cover up feelings of loneliness and a hunger for acceptance.

reaction turbine A stator vane and rotor blade arrangement, whereby the vanes form straight ducts and the blades form convergent ducts. Gases leaving the trailing edge of the blades turn the rotor. The design is common to turbine-type accessories such as air-starters.

reactive current A current in an AC circuit not in phase with the voltage.

reactive metal A metal such as aluminum or magnesium, which reacts with oxygen to form corrosion.

reactive power The power in a reactive AC circuit that subtracts from the power that would be present in a purely resistive circuit. This represents energy that is alternately stored and released by the action of inductors and capacitors.

reactor 1. A device in an AC circuit used to add reactance to it. 2. A small coil installed in an alternating current circuit to furnish inductive reactance and cancel some of the capacitive reactance in the circuit.

read back Repeat my message back to me.

reader A machine that magnifies the information on microfilm or microfiche so it can be read. Some readers can make printed paper copies.

readiness A principle of learning that the eagerness and single-mindedness of a person toward learning affect the outcome of the learning experience.

real number A number that is rational or irrational, not imaginary.

real power The power in an AC circuit that is the product of the voltage and the current in phase with that voltage. Real power equals the voltage multiplied by the current multiplied by the power factor.

ream To enlarge and smooth a drilled hole with a precision cutting tool called a reamer. A hole is reamed in preparation for work with close-tolerance parts.

reamer A sharp edged cutting tool used for enlarging or tapering drilled holes in preparation for work with close-tolerance parts.

rebreather bag A bag connected to an oxygen mask that allows expired air to be mixed with a fixed rate of oxygen. It allows users to rebreath a portion of each expired breath.

rebreather oxygen mask An oxygen mask with a rebreather bag attached.

receiver In communication, the listener, reader, or student who takes in a message containing information from a source, processes it, reacts with understanding, and changes behavior in accordance with the message.

receiver autonomous integrity monitoring (RAIM) A technique whereby a civil GNSS (Global Navigation Satellite System) receiver/processor determines the integrity of the GNSS navigation signals without reference to sensors or non-DoD integrity systems other than the receiver itself. This determination is achieved by a consistency check among redundant pseudorange measurements.

receiving controller A controller/facility receiving control of an aircraft from another controller/ facility.

receiving facility See receiving controller.

recency A principle of learning that things learned today are remembered better than things that were learned some time ago. The longer time that passes, the less that will be remembered. Instructors use this principle when summarizing the important points at the end of a lecture in order that the students will better remember them.

 

 

team img 2

RECIPROCAL

reciprocal A reverse bearing, opposite in direction by 180 .

reciprocating engine An engine that converts the heat energy from burning fuel into the reciprocating movement of the pistons. This movement is converted into a rotary motion by the connecting rods and crankshaft.

reciprocating motion An alternating back-and-forth motion.

reciprocating saw A power-driven saw that cuts material by driving a blade back and forth.

recirculating fan A fan in an aircraft cabin comfort system that circulates the air in the cabin without taking in any outside air.

reclaimed oil Lubricating oil that has already been used and is restored to a useful state by removing impurities.

reconditioning a cell Procedure of servicing a nicad battery cell by completely discharging it and then bringing it and all other cells in the battery back up to a full state of charge. Reconditioning equalizes the cells for optimum performance.

reconformance The automated process of bringing an aircraft s Current Plan Trajectory into conformance with its track.

rectangle A closed plane figure with four sides and four right angles. The opposite sides of the figure are parallel and equal in length.

rectifier A device that converts alternating current into direct current. In effect, it is an electron check valve.

rectifier bridge A rectifier using four diodes arranged in a bridge circuit.

recurring Happening again and again at regular or frequent intervals.

recurring Airworthiness Directive An Airworthiness Directive that requires compliance at regular hourly or calendar time periods.

red brass A copper-zinc alloy containing approximately 85% copper and 15% zinc. It is somewhat stronger than commercial bronze and is hardened by cold working.

red line A red mark on an aircraft instrument that indicates a maximum allowable operating condition.

red rust A nonmagnetic iron oxide.

red-line condition The maximum safe condition at which a unit can operate. Most aircraft instruments are marked with a red line indicating the boundaries of their operating limits.

reduce speed to (speed) An ATC procedure used to request pilots to adjust aircraft speed to a specific value for the purpose of providing desired spacing. Pilots are expected to maintain a speed of plus or minus 10 knots or 0.02 mach number of the specified speed.

reduction factor A constant (usually 100 or 1,000) by which a moment is divided to obtain a moment index. A moment index is used to simplify weight and balance computations.

reduction gear train The gear arrangement of an operating unit in which the output shaft turns slower than the input shaft. An example of this is a gear arrangement in an aircraft engine that allows the engine to turn at a faster speed than the propeller.

reduction gears The gear arrangement in an aircraft engine that allows the engine to turn at a faster speed than the propeller.

Reed and Prince screw A recessed-head, cross-point screw driven by a special cross-point screwdriver whose tip has a single taper.

reed valve A thin, leaf-type valve located in the valve plate of a reciprocating-type air conditioning compressor to control the inlet and outlet of the refrigerant.

reface To resurface an object in order to remove imperfections or wear marks.

reference datum An imaginary vertical plane from which all horizontal distances are measured for balance purposes.

reference datum An imaginary vertical plane at or near the nose of an aircraft from which all horizontal distances are measured for weight and balance calculations.

reference designator A combination of letters and numbers used to identify a component or assembly. Reference designators are stackable, meaning a full reference designator identifies the major assembly, subassemblies, and the actual component.

reference dimensions The dimensions on an installation drawing required to illustrate the relationship between two parts.

reference junction One of the two junctions in a thermocouple system. The reference junction is held at a constant or stable temperature to serve as a reference for the measuring junction.

reference pressure The pressure in the outflow valve control established by cabin air pressure flowing through the cabin air filter and orifice. It is metered by the reference pressure metering valve.

refining A petroleum extraction process in which crude oil is broken down into all of its different parts.

reflective A reflective student considers all possibilities or alternatives before making a decision.

reflector A surface that reflects light.

refrigerant A fluid used in an air conditioning system to absorb heat from the cabin and carry it to a radiator where it can be transferred to the outside air.

refrigerant 12 Dichlorodifluoromethane, a chemical compound used in many aircraft air conditioning systems. Also referred to as R-12.

regeneration A process in an electrical circuit in which part of the output is fed back to the input to causes amplification.

regenerative braking A method of slowing a motor by switching the wiring effectively to make it into a generator. This applies a load to the rotating mass and slows the motor.

regional checkout A checkout that goes beyond learning about a particular airplane and encompasses learning how to fly in a specific region. Before flying or giving flight instruction in any unfamiliar environment, obtain a regional checkout from a qualified CFI who is experienced in that geographical area. For example, mountain flying offers some breathtaking scenery and wonderful experiences, but it also has some unique challenges and can be extremely dangerous to inexperienced pilots.

registration certificate The document in an airplane that contains the name and address of the person to whom the airplane is registered.

regulated power supply An electrical device that converts AC voltage to DC output voltage that remains constant under changing load conditions.

Reid vapor pressure The amount of pressure acting on a liquid to hold the vapors in the liquid at a given temperature.

reinforce To strengthen by adding extra support or material.

reinforced shell The outer skin of an aircraft reinforced by a complete framework of structural members.

reinforcement In composites, material used to strengthen the matrix. Fiber reinforced plastic is an example. Fibers are used to reinforce the plastic material.

reinforcing tape A narrow, woven cotton or polyester tape used as reinforcement at stitching attachments.

rejuvenation The restoring of resilience to a dope film by opening up the film with potent solvents and allowing the plasticizers in the rejuvenator to replace those that have migrated from the dope.

rejuvenator A finishing material consisting of potent solvents and plasticizers used to restore resilience to weathered and cracked dope film.

relative bearing An angular relationship between two objects measured in degrees clockwise from the twelve o clock position of the first object.

relative humidity 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.

relative motion The motion of one object with relation to another.

relative movement The movement of one object with relation to another.

relative vorticity Rotation due entirely to the flow of air at the point being measured. Absolute vorticity is relative vorticity plus rotation imparted by the turning of the Earth (planetary vorticity).

relative wind The airflow caused by the motion of the aircraft through the air. Relative wind, also called relative airflow is opposite and parallel to the direction of flight.

relaxation oscillator An electronic oscillator that produces pulses at an interval dependent on one or more RC time constants.

relay An electrically operated remote switch with contacts that are closed or opened by an electromagnetic field.

relay question Used in response to a student s question. The question is redirected to the group in order to stimulate discussion.

release film In composites, a layer of plastic material used in the vacuum bagging process that does not allow resin to bleed through it. It will not bond to the part when the resins cure. Perforated release film will allow some resin to bleed through.

release time A departure time restriction issued to a pilot by ATC (either directly or through an authorized relay) when necessary to separate a departing aircraft from other traffic.

release time [ICAO] Time prior to which an aircraft should be given further clearance or prior to which it should not proceed in case of radio failure.

reliability Producing consistent results on multiple tests.

relief The amount one plane surface is set below or above another plane, usually for clearance or for economy in machining.

relief hole A hole drilled in a flat sheet metal part to allow intersecting bends to be made. The relief hole prevents the metal from buckling.

relief map A map that shows land forms with contour lines, shading, or color.

relief tube A urinal on an aircraft that drains overboard. The discharge area around these tubes is an area highly susceptible to corrosion.

relief valve A valve that limits the pressure in a system by releasing unwanted pressure at a preset value.

reluctance 1. The relative difficulty with which magnetic domains can be aligned. 2. The opposition to magnetic flux. The opposite of permeability.

remainder The result of subtracting one number from another or the amount left when one number does not divide evenly into another.

remanufactured engine An engine assembled by the manufacturer or his authorized agent using used parts that are held to the new parts dimensional limits. A remanufactured engine is given zero time records and usually the same warranty and guarantee as a new engine.

remote communications air/ground (RCAG) facility An unmanned VHF/UHF transmitter/ receiver facility used to expand ARTCC air/ ground communications coverage and to facilitate direct contact between pilots and controllers. RCAG facilities are sometimes not equipped with emergency frequencies 121.5 MHz and 243.0 MHz.

remote communications outlet(RCO) An unmanned communications facility remotely controlled by air traffic personnel. RCOs serve FSSs. RTRs (Remote Transmitter/ Receivers) serve terminal ATC facilities. An RCO or RTR can be UHF or VHF and will extend the communication range of the air traffic facility. There are several classes of RCOs and RTRs. The class is determined by the number of transmitters or receivers. Classes A through G are used primarily for air/ground purposes. RCO and RTR class O facilities are nonprotected outlets subject to undetected and prolonged outages. RCO (O s) and RTR (O s) were established for the express purpose of providing ground-to-ground communications between air traffic control specialists and pilots located at a satellite airport for delivering enroute clearances, issuing

departure authorizations, and acknowledging instrument flight rules cancellations or departure/landing times. As a secondary function, they can be used for advisory purposes whenever the aircraft is below the coverage of the primary air/ground frequency

remote control The control of an object with radio signals from a remote location.

remote (slave) scope A cathode-ray tube that duplicates the display of a primary radar scope.

remote transmitter/receiver See remote communications outlet.

Rene metal A nickel chromium alloy used in the manufacturing of gas turbine engines.

repair To restore an item to a condition of practical operation or to its original condition.

repairman license A certificate issued by the FAA to a person employed by a repair station, a certified commercial operator, or a certified air carrier required to provide a continuous airworthiness maintenance program. The repairman license is valid only as long as the person holding the license is employed by the company for which the certificate was issued.

repeater indicator An instrument that repeats the information via a master indicator.

repeating decimal A fraction that cannot be expressed as a definite number. The fraction 1/3 is a repeating decimal (0.333333333).

report Used to instruct pilots to advise ATC of specified information; e.g., Report passing Hamilton VOR.

reporting point A geographical location in relation to the reported position of an aircraft.

repression Theory of forgetting where a person is more likely to forget information that is unpleasant or produces anxiety.

repression A process in which a person subconsciously forgets or excludes unpleasant or anxiety producing information.

repulsion The force that tends to cause objects to move away from each other.

repulsion motor The repulsion motor consists of stator (field) windings that are powered by input power and rotor windings that have current induced by the magnetic field of the stator windings. The rotor windings are connected to the commutator and the brushes are connected to each other completing a circuit through windings within the rotor. The closed-loop circuits in the rotor are effectively the short-circuited secondaries of a transformer, where the motor s field windings are the primary coil. The currents induced in the rotor create a magnetic field that repels that of the field winding (Lenz s law). This repulsion causes the rotor to turn because the brushes are offset from the field poles, so that the repulsive forces are pushing on the rotor tangential to the rotation axis of the rotor. The brushes can be shifted to control the speed and direction of rotation.

request full route clearance Used by pilots to request that the entire route of flight be read verbatim in an ATC clearance. Such request should be made to preclude receiving an ATC clearance based on the original filed flight plan when a filed IFR flight plan has been revised by the pilot, company, or operations prior to departure.

required equipment Equipment determined by the FAA to be necessary for an aircraft to be considered airworthy.

required inspection item (RII) A designation of items of maintenance and alteration that could result in a failure, malfunction, or defect endangering the safe operation of the aircraft if an inspection is not properly performed or if improper parts or materials are used.

required navigation performance (RNP) A statement of the navigational performance necessary for operation within a defined airspace. The following terms are commonly associated with RNP:

a. Required Navigation Performance Level or Type (RNP-X). A value, in nautical miles (NM), from the intended horizontal position within which an aircraft would be at least 95-percent of the total flying time.

b. Required Navigation Performance (RNP) Airspace. A generic term designating airspace, route(s), leg(s), operation(s), or procedure(s) where minimum required navigational performance (RNP) have been established.

c. Actual Navigation Performance (ANP). A measure of the current estimated navigational performance. Also referred to as Estimated Position Error (EPE).

d. Estimated Position Error (EPE). A measure of the current estimated navigational performance. Also referred to as Actual Navigation Performance (ANP).

e. Lateral Navigation (LNAV). A function of area navigation (RNAV) equipment that calculates, displays, and provides lateral guidance to a profile or path.

f. Vertical Navigation (VNAV). A function of area navigation (RNAV) equipment that calculates, displays, and provides vertical guidance to a profile or path.

rescue coordination center (RCC) A search and rescue (SAR) facility equipped and manned to coordinate and control SAR operations in an area designated by the SAR plan. The U.S. Coast Guard and the U.S. Air Force have responsibility for the operation of RCCs.

rescue co-ordination centre [ICAO] A unit responsible for promoting efficient organization of search and rescue service and for co-ordinating the conduct of search and rescue operations within a search and rescue region.

reserve To keep something back or set it apart for use in an emergency or for a special purpose.

reservoir A place where an extra supply of something is kept, for example, a tank in which fluid is stored.

residual The remainder or anything that is left over.

residual charge The remaining electrical charge left on capacitor plates after they have been discharged.

residual fuel or oil The fuel or oil that is trapped in the lines and, therefore, not usable. In weight and balance computations, residual fuel and oil are considered to be part of an aircraft s empty weight.

residual magnetic flux The magnetism that remains in the core of an electromagnet after the magnetizing current no longer flows in the coil. Also referred to as residual magnetism.

residual magnetism The magnetism that remains in the core of an electromagnet after the magnetizing current no longer flows in the coil. Also referred to as residual magnetic flux.

residual magnetism testing inspection An inspection for magnetism that might be left in a ferrous part following magnetic particle inspection. The test is conducted with a magnetic indicator that discloses any remaining magnetic field. It is important that all residual magnetism be removed so that ferrous particles are not attracted to it.

resignation A negative self-concept is the factor that contributes most to a student s failure to a remain receptive to new experience, and which creates a tendency to reject additional training.

resin A family of natural or synthetic fluids or semi-solid substances that can be changed into a solid such as plastic through the addition of appropriate catalyzers.

resin rich In composites, an area that has an excess amount of matrix. A resin rich laminate usually is more brittle and weighs more than laminates with the proper amount of resin.

resin ridge In composites, a ridge of excess resin that contains only resin.

resin starved In composites, an area deficient in resin. A resin-starved part will not exhibit the structural strength that a part made with the proper amount of resin.

resin system In composites, a mixture of resin and ingredients required for the intended processing method and final product.

resin transfer molding (RTM) In composites, a manufacturing process in which the resin/catalyst mixture is pumped into a two-sided mold in which a fabric reinforcement has been placed. The part is then heated and cured.

resistance decade box An electrical test device that provides the capability to insert selected values of resistance into a circuit.

resistance furnace A high-temperature furnace heated by passing current through various high resistance materials.

resistance (R) The opposition to the flow of electrons offered by a device or material. Opposition by resistance causes a loss of power.

resistance thermometer A temperature-measuring device based on the linear change in resistance of a material as temperature varies. This device is connected to a Wheatstone bridge to determine resistance and thus temperature.

resistance welding The fusion of metals by clamping them together and passing a high amperage electrical current through the joint. The resulting heat melts the metal and the pressure causes the two pieces to fuse together. Spot and seam welding are forms of electrical resistance welding.

resistance wire A wire made from a high resistance material, used in wire-wound resistors and heating elements.

resistive circuit In electronics, a circuit constructed entirely of resistive elements (no capacitive or inductive components). In such a circuit, the voltage and current are in phase.

resistive current The current in a circuit where current is in phase with voltage.

resistivity The ability of a material to resist the flow of electrons. It is the opposite of conductivity.

resistor An electrical circuit element used to provide a voltage drop by dissipating some of the electrical energy in the form of heat.

resistor color code A color code marking system used to identify the resistance value of carbon resistors. Measured in ohms. The resistor is marked by either three or four colored bands. The first colored band (nearest the end of the resistor) indicates the first digit. The second colored band indicates the second digit. The third colored band indicates the number of zeros to be

added to the two digits derived from the first and second bands. If there is a fourth colored band, it is used as an indication of percentage of tolerance.

resistor power dissipation rating The amount of power a resistor can safely dissipate in the form of heat under controlled conditions.

resistor spark plug A shielded spark plug with a composition resistor installed in the barrel. The resistor limits the current stored in the capacitive effect of the shielding. This minimizes electrode erosion and increases the life of the spark plug.

resolution The ability to distinguish between indications on a display. One example would be the ability to distinguish between two radar returns displayed on a cathode-ray tube.

resolution advisory A display indication given to the pilot by the traffic alert and collision avoidance systems (TCAS II) recommending a maneuver to increase vertical separation relative to an intruding aircraft. Positive, negative, and vertical speed limit (VSL) advisories constitute the resolution advisories. A resolution advisory is also classified as corrective or preventive.

resonance A frequency in any given RLC (Resistance, Inductance, Capacitance) AC circuit at which the capacitive reactance is equal to the inductive reactance.

resonance method of ultrasonic inspection A method of detecting material thickness or indications of internal damage by injecting variable frequency ultrasonic energy into a material. A specific frequency of energy produces the greatest return in a given thickness of material. When the equipment is calibrated for a specific thickness and this thickness changes, an aural or visual indication is given.

resonant circuit An electrical circuit in which the inductive reactance is equal to the capacitive reactance. They will be equal at a particular frequency called the resonant frequency. The circuit can be made resonant by either varying the frequency until resonance occurs, or holding the frequency constant and varying inductance or capacitance to achieve resonance.

resonant frequency The frequency of a source of vibration that is exactly the same as the natural vibration frequency of a structure.

resonate To vibrate at a certain frequency. A mechanical system is said to resonate when its natural vibration frequency is the same as that of the force applied. The level of vibration of an object increases immensely as that frequency is reached and will be less on either side of that frequency.

resource use An essential part of ADM training. Since useful tools and sources of information may not always be readily apparent, it is important to teach students how to recognize appropriate resources. Resources must not only be identified, but students must develop the skills to evaluate whether they have the time to use a particular resource and the impact its use will have upon the safety of flight.

respirator A device worn over the mouth and nose to prevent the harmful inhaling of dangerous substances.

responses Possible answers to a multiple-choice test item. The correct response is often called the keyed response, and incorrect responses are called distractors.

restart The act of starting an engine after it has been operating and then shut down.

restricted area Airspace designated under FAR Part 73, within which the flight of aircraft, while not wholly prohibited, is subject to restriction. Most restricted areas are designated joint use and IFR/VFR operations in the area can be authorized by the controlling ATC facility when it is not being utilized by the using agency. Restricted areas are depicted on enroute charts. Where joint use is authorized, the name of the ATC controlling facility is also shown.

restricted area [ICAO] An airspace of defined dimensions, above the land areas or territorial waters of a State, within which the flight of aircraft is restricted in accordance with certain specified conditions.

restrictor An orifice for reducing or restricting the flow of a fluid.

resultant flux The flux in a magnetic circuit of an aircraft magneto. Resultant of the flux of the rotating permanent magnet and the flux that surrounds the primary windings when primary current is flowing.

resultant lift The vector sum of the magnitude and direction of all of the lift forces produced by an airfoil.

resultant relative wind In rotorcraft, airflow from rotation that is modified by induced flow.

resume normal speed Used by ATC to advise a pilot that previously issued speed control restrictions are deleted. An instruction to resume normal speed does not delete speed restrictions that are applicable to published procedures of upcoming segments of flight, unless specifically stated by ATC. This does not relieve the pilot of those speed restrictions that are applicable to FAR 91.117.

resume own navigation Used by ATC to advise a pilot to resume his own navigational responsibility. It is issued after completion of a radar vector or when radar contact is lost while the aircraft is being radar vectored.

retard To slow or delay the progress of something.

retard breaker points An auxiliary set of breaker points in a magneto equipped with the Shower of Sparks starting system. These points are operative only during the starting cycle and open later than the run, or normal,

points. This provides a late or retarded spark. Also referred to as retard points.

retard points An auxiliary set of breaker points in a magneto equipped with the Shower of Sparks starting system. These points are operative only during the starting cycle and open later than the run, or normal, points. This provides a late or retarded spark. Also referred to as retard breaker points.

retarder A slow-drying solvent used to prevent blushing or to provide a more glossy finish by allowing the finish a longer flow-out time.

retention There are five principles that promote deep learning and enhance retention of course material: praise stimulates remembering, recall is promoted by association, favorable attitudes aid retention, learning with all the senses is most effective, and meaningful repetition aids recall.

retentivity The ability of a material to retain its magnetic properties.

retina The photosensitive portion of the eye, made up of cells called rods and cones, that is connected to the optic nerve.

retirement schedule A list of limited life parts and the times when they must be replaced. This list records the part, serial number, time installed, and removal time.

retort A laboratory vessel with a long tube used to distill substances by heat.

retract To pull in or draw back.

retractable gear This is a pilot controllable landing gear system, whereby the gear can be stowed alongside or inside the structure of the airplane during flight.

retractable landing gear Landing gear that folds into the aircraft structure to reduce parasite drag.

retraction test The portion of an aircraft inspection in which the airplane is put on jacks and the landing gear cycled through its retraction and extension sequences.

retread In tire recapping, a tire that has been renewed to serviceable condition. Tires that meet injury limitations can be recapped. Retreading or recapping means reconditioning of a tire by renewing the tread, or renewing the tread plus one or both sidewalls.

retreating blade In rotorcraft, any blade, located in a semicircular part of the rotor disc, where the blade direction is opposite to the direction of flight.

retreating blade stall In rotorcraft, 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. In a gyroplane the stall occurs at 20 to 40 percent outboard from the hub.

retrofit To furnish something with new or modified parts or equipment not available or considered necessary at the time the part was manufactured.

return flow The upper branch of a thermal circulation.

return stroke Lightning that is visible to the eye and marks the path of the positive charge of the step leader back into the clouds.

return to service The completion of all applicable maintenance records and forms after maintenance has been performed on an aircraft that will allow the aircraft to be legally flown.

revalidate To confirm, sanction or make something valid again.

reverse bias The polarity relationship between a power supply and a semiconductor that does not allow conduction of current.

reverse idle A power lever position where the thrust reversers are deployed, but engine power is idle.

reverse pitch An angle to which the propeller blade can be turned in order to provide reverse thrust from the propeller.

reverse polarity welding In electric arc welding, reverse polarity occurs when the electrode is positive and the work is negative. The opposite polarity is called straight polarity. Straight polarity puts more heat into the work piece, while reverse polarity minimizes the heat in the work piece.

reverse question A response to a question. Rather than give a direct answer to the student s query, the instructor can redirect the question to another student to provide the answer.

reverse riveting A process of driving aircraft rivets in which the manufactured head is bucked by holding it in a rivet set supported in a bucking bar and upsetting the shank with a flush rivet set.

reverse-current relay A relay incorporated into a generator circuit to disconnect the generator from the battery when the battery voltage is greater than generator voltage.

reverse-flow annular combustor A combustor design that forms an S-shaped path in which the gases flow from the diffuser to the exhaust. This design shortens the entire engine length because the liner is coaxial to the turbines rather than in front of them as in a conventional annular combustor.

reversible-pitch propeller A propeller system with a pitch change mechanism that includes full reversing capability. When the pilot moves the throttle controls to reverse, the blade angle changes to a pitch angle and produces a reverse thrust, which slows the air

airplane down during a landing.

team img 3

REVISION

reversing mechanism A linkage that reverses the direction of movement between two parts.

review and evaluation The fourth and last step in the teaching process, which consists of a review of all material and an evaluation of the students. In the telling-and-doing technique of flight instruction, this step consists of the instructor evaluating the student s performance while the student performs the required procedure.

revision In mechanical drawings, a change in dimensions, design, or materials.

revision block That portion of an aircraft drawing that contains a record of all of the revisions. Symbols are used to indicate changes and their locations.

revolutions per minute (RPM) The number of complete revolutions a body makes in one minute.

revolved section A detail on an aircraft drawing in which the external view shows the shape of a part s cross section as though it were cut out and revolved.

Reynolds Number A dimensionless ratio that relates how smoothly a fluid flows. At low velocities fluid flow is smooth or laminar. As the fluid flows more rapidly, it reaches a velocity, known as the critical velocity, at which the motion changes from laminar to turbulent, with the formation of eddy currents and vortices that disturb the flow.

RF alternating current Radio frequency (RF) is a term that refers to alternating current (AC) that, when fed into an antenna, generates an electromagnetic field suitable for communications. These frequencies range from nine kilohertz (9 kHz) to thousands of gigahertz (GHz).

rheostat A variable resistor having only two terminals. It is normally used in a circuit to drop voltage by dissipating some of the energy as heat.

rhetorical question A question asked to stimulate group thought. Normally answered by the instructor, it is more commonly used in lecturing rather than in guided discussions.

rhomboid A parallelogram in which the angles are oblique and the adjacent sides are unequal.

rhumb line In navigation, a rhumb line crosses all lines of longitude at the same angle.

rib The structural member of an airfoil that gives it the desired aerodynamic shape.

rib cap A thin, narrow strip of material usually glued to wooden ribs or riveted to metal ribs to enlarge the contact surface for the attachment of skin to the wing or flight control surface.

rib lacing The attachment of fabric to an aircraft structure with rib stitching cord. A series of loops around the structure and through the fabric are secured with seine knots. Also referred to as rib stitching.

rib stitching The attachment of fabric to an aircraft structure with rib stitching cord. A series of loops around the structure and through the fabric are secured with seine knots. Also referred to as rib lacing.

rib stitching cord A strong cotton, linen, or polyester fiber cord used to stitch or lace fabric to an aircraft structure.

ribbon direction In composites, on a honeycomb core, the way the honeycomb can be separated. The direction of one continuous ribbon.

ribbon parachute A parachute that consists of strips or ribbons of material instead of a solid fabric. This type of chute is used in instances where it is desirable to have less opening shock, since air escapes between the ribbons.

rich flameout A condition of turbine engine operation in which the fire goes out in the engine because the fuel-air mixture is too rich to support combustion.

rich solvent A slow-drying solvent.

ridge/ridge line In meteorology, an elongated area of relatively high atmospheric pressure; usually associated with and most clearly identified as an area of maximum anticyclonic curvature of the wind flow (isobars, contours, or streamlines).

rigging The final adjustment and alignment of an aircraft and its flight control system that provide the proper aerodynamic characteristics.

rigging fixture A template designed to measure control surface travel.

rigging pins The pins that can be inserted into control system components to hold the controls in their neutral position for rigging the control cables and rods.

right angle A 90 angle. Formed by the perpendicular intersection of two straight lines.

right brain A concept that each hemisphere of the brain processes information differently. Students with right-brain dominance are characterized as being spatially oriented, creative, intuitive, and emotional. They can be very good with art or music and can easily put together the big picture.

right-hand rule for the direction of magnetic flux A method of determining the relation of the flow of magnetic flux to the direction of current flow in a conductor. The right hand is wrapped around the conductor with the thumb pointing in the direction of current flow (positive to negative), and the fingers will point in the direction of the flow of magnetic flux from the north pole to the south pole.

right-hand rule of electric generators A method of determining the relative directions of current flow, magnetic flux, and motion of a conductor when the

conductor is passing through a magnetic field. The right hand should be held with the thumb pointing vertically, the first finger pointing away, and the second finger pointing to the left (the thumb and two fingers will be at right angles to each other). The thumb points in the direction the conductor is moving. The first finger points in the direction of the lines of magnetic flux (north pole to south pole), and the second finger points in the direction of current flow (positive to negative) within the conductor.

right-hand thread A thread that, when viewed axially, winds in a clockwise and receding direction. All threads are right-hand threads unless otherwise designated.

rigid airship A dirigible that has a rigid framework covered with cloth fabric and a cabin suspended underneath the frame that houses the crew and engines for driving it through the air.

rigid rotor In rotorcraft, a rotor system permitting blades to feather but not flap or hunt.

rigid tubing Fluid lines made of thin wall aluminum alloy, copper, or stainless steel used in an aircraft when there is no relative movement between the ends of the tube.

rigidity The state of being rigid.

rigidity in space The principle that a wheel with a heavily weighted rim spun rapidly will remain in a fixed position in the plane in which it is spinning.

rime ice The rough textured ice that forms on a surface, such as the leading edge of an airplanes wing, when flown through supercooled fog or certain types of clouds.

rime icing The formation of a white or milky and opaque granular deposit of ice formed by the rapid freezing of supercooled water droplets as they impinge upon an exposed aircraft.

ring and tube assembly The ring of outer combustion chambers on a multiple-can-type combustor engine.

ring cowl A streamlined covering over the cylinders of a radial engine.

ring gear One of the gears in a turboprop negative torque signal and prop reduction gear system. When a predetermined negative torque is applied to the reduction gearbox, the ring gear moves forward against the spring force due to a torque reaction generated by helical splines. In moving forward, the ring gear pushes two operating rods through the reduction gear nose.

ring grooves The grooves in the circumference of a piston into which the piston rings fit.

ringworms A circular pattern of cracks in a brittle dope finish that results from a blunt object pressing against the fabric.

rip panel A free floating balloon s air dump panel that can be opened by pulling a rip-cord. Air is dumped for landings or in the event of an emergency.

ripple A small periodic variation in the voltage level of a direct current power supply.

ripple filter A filter consisting of capacitors or inductors, or both, that attenuates the AC component in the output of a rectifier circuit. The ripple is the amount of AC that remains on the DC.

ripple frequency The frequency of the ripple in DC voltage when rectified from an AC current. A full-wave rectifier produces a ripple frequency of twice the input AC frequency while a half-wave rectifier produces a ripple frequency that is the same as the input frequency.

ripsaw A saw with course teeth used for cutting lumber along the direction of its grain.

risk elements How to assess risk is a skill that students need to learn to make effective decisions. When students are faced with making a decision regarding a flight, ask them to evaluate the status of the four risk elements: the pilot in command, the aircraft, the environment, and the operation.

risk elements in ADM In aeronautical decision making the four elements considered are the pilot, aircraft, environment, and type of operation.

risk management Part of the decision making process. Situational awareness, problem recognition, and good judgment are used to reduce risks.

rivet A small metal pin with a specially formed head on one end used to fasten sheet metal parts together by upsetting the shank to form a clamping head.

rivet cutter A tool used to cut rivets to the required length.

rivet gauge The transverse pitch or distance between rows of rivets.

rivet gun A hand-held pneumatic riveting hammer used to vibrate aircraft rivets against a heavy bucking bar to form the upset head.

rivet pitch The distance between the center of rivet holes in adjacent rows. Also referred to as rivet spacing.

rivet set A tool that fits into a rivet gun used to hammer against the manufactured head of a rivet so the bucking bar can form the upset head on the opposite side of the skin. Also referred to as a rivet snap.

rivet spacing The distance between the center of rivet holes in adjacent rows. Also referred to as rivet pitch.

rivet squeezer A heavy, tong-like clamping machine used to squeeze the ends of a rivet to form an upset head.

riveting burr A small plain washer placed on a rivet before the rivet is upset. Provides a larger area of contact on the part than would have been provided with the rivet alone.

Rivnut A patented, hollow, blind rivet manufactured by the B.F Goodrich Company, in which the inside of the shank is threaded. The upset rivet can be used as a blind nut.

RNAV approach An instrument approach procedure that relies on aircraft area navigation equipment for navigational guidance.

RNAV DP A departure procedure developed for RNAV-equipped aircraft whose ground track is based on satellite or DME/DME navigation systems.

RNAV way point (W/P) A predetermined geographical position used for route or instrument approach definition or progress reporting purposes that is defined relative to a VORTAC station position.

road reconnaissance Military activity requiring navigation along roads, railroads, and rivers. Reconnaissance route/route segments are seldom along a straight line and normally require a lateral route width of 10NM to 30NM and an altitude range of 500 feet to 10,000 feet AGL.

robot An automated mechanism built to do functions ordinarily assigned to humans.

robotics The research and development of technology that deals with the design, application, construction, and maintenance of automated mechanisms.

rock wool A mineral wool made by blowing a jet of steam through molten rock and used chiefly for heat and sound insulation

rocker arm A pivoted arm, as in an aircraft reciprocating engine, used to transfer pushrod motion to a valve stem.

rocker arm boss That portion of the cylinder head of an aircraft engine that provides support for the rocker arm shaft.

rocket A device propelled by the high-velocity ejection of gases produced by internal ignition of solid or liquid fuels.

rocket assisted takeoff An auxiliary means of assisting an aircraft when taking off. The system consists of small rockets fastened to the aft structure. When a heavily loaded aircraft rotates for takeoff, the jets are fired. The added boost provides extra thrust needed for takeoff. Once airborne the rockets are jettisoned. Often abbreviated as JATO.

rocket fuel Any fuel specifically developed for rocket engines.

rocket ship Any spacecraft that uses rocket engines for propulsion.

rocketry The study, theory, and development of rockets.

rocking shaft A shaft or rod in an instrument that oscillates or rocks upon its bearings, but does not revolve.

Rockwell hardness tester A machine used to determine the hardness of a material by using a calibrated weight to press either a diamond pyramid or a hardened steel ball into the material. A dial indicator measures the depth of penetration and specifies it with a Rockwell number.

rods The cells concentrated on the outside of the foveal area of the eye that are sensitive to low light and not to color.

roger During communications, this indicates: I have received all of your last transmission. Roger should not be used to answer a question requiring a yes or no answer.

role model A person whose behavior in a particular role is imitated by others.

roll The motion of an aircraft about its longitudinal axis. This motion is controlled by the ailerons.

roll cloud The dense and horizontal cloud band occasionally found parallel to gust fronts. Also used to describe the rotor clouds associated with mountain lee waves.

roll pin A pressed-fit pin made of a roll of spring steel. The spring force tending to unroll the pin holds it tight in the hole.

roll threading Applying a thread to a bolt or screw by rolling the piece between two grooved die plates, one of which is in motion, or between rotating grooved circular rolls.

roller bearing An antifriction bearing with hardened steel rollers between two hardened steel races.

rollout RVR The RVR (Runway Visual Range) readout values obtained from RVR equipment located nearest the rollout end of the runway.

root The supporting base or structure, as in the wing root, connected to the fuselage.

root mean square (RMS) The value of direct current equivalent to an alternating current sine wave. The value is 0.707 times the peak value of one alternation.

rosette weld A weld made through a small hole in a piece of steel tubing to weld an inner tube to the outer tube to prevent relative movement.

rotary breather A rotating set of vanes or a centrifuge device through which oil laden air from the vent subsystem passes. Deaeration takes place and the oil is returned to the sump while the air exits back to the atmosphere.

rotary pick-off A device attached to a rotating object that generates a signal proportional to the amount of rotation.

rotary radial engine An aircraft engine popular in World War I, in which the propeller was attached to the crankcase and the pistons were attached to a crankshaft mounted on the airframe. When the engine ran, the cylinders, crankcase, and propeller all rotated and the crankshaft remained stationary.

rotary solenoid An electromagnet whose movable core is rotated by current through the coil.

rotary switch A switch that consists of one or more circular wafers, each with multiple contacts. A central shaft rotates a wiper from contact to contact, switching connection from one circuit to another. When multiple wafers are stacked on the shaft, multiple circuits can be selected simultaneously.

rotating wing The rotors of a helicopter.

rotation The act of turning about an axis.

rotational velocity In rotorcraft, the component of relative wind produced by the rotation of the rotor blades.

rote learning A basic level of learning where the student has the ability to repeat back something learned, with no understanding or ability to apply what was learned.

rotor 1. The rotating element in an alternator. It is excited by direct current, and the interlacing fingers on the faces of the rotor form the alternating north and south poles. 2. The rotating blades of a helicopter. 3. The portion of a turbine compressor that spins. 4. Either compressor or turbine. A rotating disk or drum to which a series of blades is attached. 5. In meteorology, a turbulent circulation under mountain-wave crests, to the lee and parallel to the mountains creating the wave. Glider pilots use the term rotor to describe any low-level turbulent flow associated with mountain waves.

rotor brake A device used to stop the rotor blades of a rotorcraft on shutdown. This can be either a hydraulic or mechanical mechanism.

rotor disc The area within the tip path plane of a helicopter s rotor. Also referred to as the disc area.

rotor disc area In rotorcraft, the area swept by the blades of the rotor. It is a circle with its center at the hub and has a radius of one blade length.

rotor force The force produced by the rotor in a gyroplane. It is comprised of rotor lift and rotor drag.

rotor streaming In meteorology, a phenomenon that occurs when the air flow at mountain levels can be sufficient for wave formation, but begins to decrease with altitude above the mountain. In this case, the air downstream of the mountain breaks up and becomes turbulent, similar to rotor, with no lee waves above.

rotorcraft A heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors.

rotorcraft-load combination The combination of a rotorcraft and an external-load, including the external-load attaching means.

rotorcraft-load combinations Class A, Class B, Class C, and Class D rotorcraft-load combinations, as follows:

Class A one in which the external load cannot move freely, cannot be jettisoned, and does not extend below the landing gear.

Class B one in which the external load is jettisonable and is lifted free of land or water during the rotorcraft operation.

Class C one in which the external load is jettisonable and remains in contact with land or water during the rotorcraft operation.

Class D 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.

round file A steel tool that has a circular cross section with hardened ridged surfaces, used for smoothing, grinding, or boring. Also referred to as a rattail file.

round head A fastener with a semi-elliptical top surface and a flat bearing surface.

round off 1. To make an edge round as by filing. 2. In mathematics, to change a fraction to the closest whole number.

round-nose pliers Pliers with round jaws. Used to form loops in wire and thin strips of sheet metal.

route A defined path, consisting of one or more courses in a horizontal plane, which aircraft traverse over the surface of the Earth.

route segment 1. A part of a route. Each end of that part is identified by: a. A continental or insular geographical location; or b. A point at which a definite radio fix can be established. 2. As used in Air Traffic Control, a part of a route that can be defined by two navigational fixes, two NAVAIDs, or a fix and a NAVAID.

route segment [ICAO] A portion of a route to be flown, as defined by two consecutive significant points specified in a flight plan.

router An electric machine that uses a high-speed, rotary cutting tool. In aircraft maintenance, routers are often used to remove damaged honeycomb core from a bonded aircraft structure.

routine service items The items in a progressive inspection that consists of a thorough check of the aircraft, engines, appliances, components, and systems normally without disassembly.

roving A bundle of filaments that are twisted together for weaving into fabric.

rubber cement An adhesive made from rubber that has not gone through the vulcanization process but has been dissolved in solvent.

rudder The vertically hinged control surface used to effect horizontal changes in course or rotate an aircraft about its vertical axis. The pilot operates the rudder by the movement of the foot pedals in the cockpit.

rudder pedals The foot-operated controls in an airplane that move the rudder.

ruddervator A pair of control surfaces on the tail of an aircraft arranged in the form of a V. These surfaces, when moved in the same direction vertically by the control wheel, serve as elevators. When moved in the same direction horizontally by the rudder pedals, they serve as a rudder.

rule A straightedge usually with etched, calibrated, dimensional markings.

rumble A combustor noise caused by choking and unchoking of the turbine nozzle. Caused by improper fuel scheduling.

run 1. A defect in a painted surface caused by too much finish being applied. The material gathers and attempts to flow off the surface. 2. To set something in motion, such as running an engine.

run-in The period of time an aircraft engine is operated to seat the moving parts after an overhaul.

running fit A fit between moving parts that allows them to move freely.

runout A term frequently used interchangeable with eccentricity but which normally refers to the amount which the outside surface of one component moves with respect to the outside surface of another component. As such, it includes eccentricity, angularity and bow. The amount of runout is usually expressed in terms of Total Indicator Reading (TIR).

runout check A dial indicator check for measuring the plane of rotation of a rotor shaft or disc.

runway A defined rectangular area on a land airport prepared for the landing and takeoff run of aircraft along its length. Runways are normally numbered in relation to their magnetic direction rounded off to the nearest 10 degrees; e.g., Runway 1 (010 ), and Runway 25 (250 ).

runway centerline lighting Flush centerline lights spaced at 50-foot intervals beginning 75 feet from the landing threshold and extending to within 75 feet of the opposite end of the runway.

runway condition reading Numerical decelerometer readings relayed by air traffic controllers at USAF and certain civil bases for use by the pilot in determining runway braking action. These readings are routinely relayed only to USAF and Air National Guard Aircraft.

runway edge lights (ICAO) Are provided for a runway intended for use at night or for a precision approach runway intended for use by day or night. Runway edge lights shall be fixed lights showing variable white, except that:

a. in the case of a displaced threshold, the lights between the beginning of the runway and the displaced threshold shall show red in the approach direction; and

b. a section of the lights 600m or one-third of the runway length, whichever is the less, at the remote end of the runway from the end at which the take-off run is started, may show yellow.

 

 

team img 4

RUNWAY

runway end identifier lights Two synchronized flashing lights, one on each side of the runway threshold, which provide rapid and positive identification of the approach end of a particular runway.

runway gradient The average slope, measured in percent, between two ends or points on a runway.

runway heading The magnetic direction that corresponds with the runway centerline extended, not the painted runway number. When cleared to fly or maintain runway heading, pilots are expected to fly or maintain the heading that corresponds with the extended centerline of the departure runway. Drift correction shall not be applied; e.g., if the actual magnetic heading of the runway centerline of Runway 4 is 044 , a heading of 044 should be flown..

runway in use/active runway/duty runway Any runway or runways currently being used for takeoff or landing. When multiple runways are used, they are all considered active runways. In the metering sense, a selectable adapted item that specifies the landing runway configuration or direction of traffic flow. The adapted optimum flight plan from each transition fix to the vertex is determined by the runway configuration for arrival metering processing purposes.

runway incursion Any occurrence at an airport involving an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off, intending to takeoff, landing, or intending to land.

runway lights Lights having a prescribed angle of emission used to define the lateral limits of a runway. Runway lights are uniformly spaced at intervals of approximately 200 feet, and the intensity can be controlled or preset.

runway markings 1. Basic marking Markings on runways used for operations under visual flight rules consisting of centerline markings and runway direction numbers and, if required, letters. 2. Instrument marking Markings on runways served by nonvisual navigation aids and intended for landings under instrument weather conditions, consisting of basic marking plus threshold markings. 3. All-weather (precision instrument) marking Marking on runways served by nonvisual precision approach aids and on runways having special operational requirements, consisting of instrument markings plus landing zone markings and side strips.

team img 4

 

unway overrun In military aviation exclusively, a stabilized or paved area beyond the end of a runway, of the same width as the runway plus shoulders, centered on the extended runway centerline.

runway profile descent An instrument flight rules (IFR) air traffic control arrival procedure to a runway published for pilot use in graphic and/or textual form and may be associated with a STAR. Runway Profile Descents provide routing and may depict crossing altitudes, speed restrictions, and headings to be flown from the enroute structure to the point where the pilot will receive clearance for and execute an instrument approach procedure. A Runway Profile Descent can apply to more than one runway if so stated on the chart.

runway safety area A defined surface surrounding the runway prepared, or suitable, for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway. The dimensions of the RSA vary and can be determined by using the criteria contained within Advisory Circular 150/5300-13, Chapter 3. The design standards dictate that the RSA shall be:

a. Cleared, graded, and have no potentially hazardous ruts, humps, depressions, or other surface variations;

b. Drained by grading or storm sewers to prevent water accumulation;

c. Capable, under dry conditions, of supporting snow removal equipment, aircraft rescue and fire fighting equipment, and the occasional passage of aircraft without causing structural damage to the aircraft; and,

d. Free of objects, except for objects that need to be located in the runway safety area because of their function. These objects shall be constructed on low impact resistant supports (frangible mounted structures) to the lowest practical height with the frangible point no higher than 3 inches above grade.

runway temperature The air temperature immediately above a runway at approximately wing level.

runway use program A noise abatement runway selection plan designed to enhance noise abatement efforts with regard to airport communities for arriving and departing aircraft. These plans are developed into runway use programs and apply to all turbojet aircraft 12,500 pounds or heavier; turbojet aircraft less than 12,500 pounds are included only if the airport proprietor determines that the aircraft creates a noise problem. Runway use programs are coordinated with FAA offices, and safety criteria used in these programs are developed by the Office of Flight Operations. Runway use programs are administered by the Air Traffic Service as Formal or Informal programs.

a. Formal Runway Use Program An approved noise abatement program defined and acknowledged in a Letter of Understanding between Flight Operations, Air Traffic Service, the airport proprietor, and the users. Once established, participation in the program is mandatory for aircraft operators and pilots as provided for in FAR 91.129.

b. Informal Runway Use Program An approved noise abatement program that does not require a Letter of Understanding, and participation in the program is voluntary for aircraft operators/pilots.

runway visibility value (RVV) The visibility determined for a particular runway by a transmissometer. A meter provides a continuous indication of the visibility (reported in miles or fractions of miles) for the runway. RVV is used in lieu of prevailing visibility in determining minimums for a particular runway.

runway visual range (RVR) An instrumentally derived horizontal distance a pilot should see down the runway from the approach end; based on the sighting of high intensity runway lights.

runway visual range (RVR) An instrumentally derived value, based on standard calibrations, that represents the horizontal distance a pilot will see down the runway from the approach end. It is based on the sighting of either high intensity runway lights or on the visual contrast of other targets whichever yields the greater visual range. RVR, in contrast to prevailing or runway visibility, is based on what a pilot in a moving aircraft should see looking down the runway. RVR is horizontal visual range, not slant visual range. It is based on the measurement of a transmissometer made near the touchdown point of the instrument runway and is reported in hundreds of feet. RVR is used in lieu of RVV and/or prevailing visibility in determining minimums for a particular runway.

a. Touchdown RVR The RVR visibility readout values obtained from RVR equipment serving the runway touchdown zone.

b. Mid RVR The RVR readout values obtained from RVR equipment located midfield of the runway.

c. Rollout RVR The RVR readout values obtained from RVR equipment located nearest the rollout end of the runway.

rust A reddish brown, crusty coating of hydrated ferric oxide that forms on iron and iron-containing materials when the material is exposed to moist air.