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From Pilots Almanac
From the FAA Pilot/Controller Glossary. Reference it for the original text. ICAO terms not included here.
Back to the Pilot/Controller Glossary Index.
RAA
(See REMOTE AIRPORT ADVISORY.)
RADAR
A device which, 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 (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
The provision of advice and information based on radar observations. (See ADVISORY SERVICE.)
RADAR ALTIMETER
(See RADIO ALTIMETER.)
RADAR APPROACH
An instrument approach procedure which utilizes Precision Approach Radar (PAR) or Airport Surveillance Radar (ASR). (See AIRPORT SURVEILLANCE RADAR.) (See INSTRUMENT APPROACH PROCEDURE.) (See PRECISION APPROACH RADAR.) (See SURVEILLANCE APPROACH.)
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. (See APPROACH CONTROL SERVICE.)
- 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 may provide services of a ground controlled approach (GCA); i.e., ASR and PAR approaches. A radar approach control facility may be operated by FAA, USAF, US Army, USN, USMC, or jointly by FAA and a military service. 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 ARRIVAL
An aircraft arriving at an airport served by a radar facility and in radar contact with the facility. (See NONRADAR.)
RADAR BEACON
(See RADAR.)
RADAR CONTACT
- a. Used by ATC to inform an aircraft that it is identified on the radar display and radar flight following will be provided until radar identification is terminated. Radar service may also be provided within the limits of necessity and capability. When a pilot is informed of "radar contact," he/she automatically discontinues reporting over compulsory reporting points.
(See RADAR CONTACT LOST.) (See RADAR FLIGHT FOLLOWING.) (See RADAR SERVICE.) (See RADAR SERVICE TERMINATED.)
- b. The term used to inform the controller that the aircraft is identified and approval is granted for the aircraft to enter the receiving controllers airspace.
RADAR CONTACT LOST
Used by ATC to inform a pilot that radar data used to determine the aircraft's position is no longer being received, or is no longer reliable and radar service is no longer being provided. The loss may be attributed to several factors including the aircraft merging with weather or ground clutter, the aircraft operating below radar line of sight coverage, the aircraft entering an area of poor radar return, failure of the aircraft transponder, or failure of the ground radar equipment. (See CLUTTER.) (See RADAR CONTACT.)
RADAR ENVIRONMENT
An area in which radar service may be provided. (See ADDITIONAL SERVICES.) (See RADAR CONTACT.) (See RADAR SERVICE.) (See TRAFFIC ADVISORIES.)
RADAR FLIGHT FOLLOWING
The observation of the progress of radar identified aircraft, whose primary navigation is being provided by the pilot, wherein the controller retains and correlates the aircraft identity with the appropriate target or target symbol displayed on the radar scope. (See RADAR CONTACT.) (See RADAR SERVICE.)
RADAR IDENTIFICATION
The process of ascertaining that an observed radar target is the radar return from a particular aircraft. (See RADAR CONTACT.) (See RADAR SERVICE.)
RADAR IDENTIFIED AIRCRAFT
An aircraft, the position of which has been correlated with an observed target or symbol on the radar display. (See RADAR CONTACT.) (See RADAR CONTACT LOST.)
RADAR MONITORING
(See RADAR SERVICE.)
RADAR NAVIGATIONAL GUIDANCE
(See RADAR SERVICE.)
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. (See RADAR ROUTE.) (See RADAR SERVICE.)
RADAR ROUTE
A flight path or route over which an aircraft is vectored. Navigational guidance and altitude assignments are provided by ATC.
(See FLIGHT PATH.) (See ROUTE.)
RADAR SEPARATION
(See RADAR SERVICE.)
RADAR SERVICE
A term which encompasses one or more of the following services based on the use of radar which 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. (See ADDITIONAL SERVICES.) (See TRAFFIC ADVISORIES.)
- b. Radar Navigational Guidance- Vectoring aircraft to provide course guidance.
- c. Radar Separation- Radar spacing of aircraft in accordance with established minima.
RADAR SERVICE TERMINATED
Used by ATC to inform a pilot that he/she 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 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 which may affect the intended route of flight of their aircraft. (See TRAFFIC ADVISORIES.)
RADAR TRAFFIC INFORMATION SERVICE
(See TRAFFIC ADVISORIES.)
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:
- a. Level 1. WEAK
- b. Level 2. MODERATE
- c. Level 3. STRONG
- d. Level 4. VERY STRONG
- e. Level 5. INTENSE
- f. Level 6. EXTREME
RADIAL
A magnetic bearing extending from a VOR/VORTAC/TACAN navigation facility.
RADIO
- a. A device used for communication.
- b. Used to refer to a flight service station; e.g., "Seattle Radio" is used to call Seattle FSS.
RADIO ALTIMETER
Aircraft equipment which makes use of the reflection of radio waves from the ground to determine the height of the aircraft above the surface.
RADIO BEACON
(See NONDIRECTIONAL BEACON.)
RADIO DETECTION AND RANGING
(See RADAR.)
RADIO MAGNETIC INDICATOR
An aircraft navigational instrument coupled with a gyro compass or similar compass that indicates the direction of a selected NAVAID and indicates bearing with respect to the heading of the aircraft.
RAIS
(See REMOTE AIRPORT INFORMATION SERVICE.)
RAMP
(See APRON.)
RANDOM ALTITUDE
An altitude inappropriate for direction of flight and/or not in accordance with FAAO 7110.65, Para 4-5-1, VERTICAL SEPARATION MINIMA.
RANDOM ROUTE
Any route not established or charted/published or not otherwise available to all users.
RC
(See ROAD RECONNAISSANCE.)
RCAG
(See REMOTE COMMUNICATIONS AIR/GROUND FACILITY.)
RCC
(See RESCUE COORDINATION CENTER.)
RCO
(See REMOTE COMMUNICATIONS OUTLET.)
RCR
(See RUNWAY CONDITION READING.)
READ BACK
Repeat my message back to me.
RECEIVER AUTONOMOUS INTEGRITY MONITORING (RAIM)
A technique whereby a civil GNSS 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.)
RECONFORMANCE
The automated process of bringing an aircraft's Current Plan Trajectory into conformance with its track.
REDUCE SPEED TO (SPEED)
(See SPEED ADJUSTMENT.)
REIL
(See RUNWAY END IDENTIFIER LIGHTS.)
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.
REMOTE AIRPORT ADVISORY (RAA)
A remote service which may be provided by facilities, which are not located on the landing airport, but have a discrete ground-to-air communication frequency or tower frequency when the tower is closed, automated weather reporting with voice available to the pilot at the landing airport, and a continuous ASOS/AWOS data display, other direct reading instruments, or manual observation is available to the AFSS specialist.
REMOTE AIRPORT INFORMATION SERVICE (RAIS)
A temporary service provided by facilities, which are not located on the landing airport, but have communication capability and automated weather reporting available to the pilot at the landing airport.
REMOTE COMMUNICATIONS AIR/GROUND FACILITY
An unmanned VHF/UHF transmitter/receiver facility which is 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
An unmanned communications facility remotely controlled by air traffic personnel. RCOs serve FSSs. RTRs serve terminal ATC facilities. An RCO or RTR may 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 en route clearances, issuing departure authorizations, and acknowledging instrument flight rules cancellations or departure/landing times. As a secondary function, they may be used for advisory purposes whenever the aircraft is below the coverage of the primary air/ground frequency.
REMOTE TRANSMITTER/RECEIVER
(See REMOTE COMMUNICATIONS OUTLET.)
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 which the position of an aircraft is reported. (See COMPULSORY REPORTING POINTS.)
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 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 which calculates, displays, and provides lateral guidance to a profile or path.
- f. Vertical Navigation (VNAV). A function of area navigation (RNAV) equipment which calculates, displays, and provides vertical guidance to a profile or path.
RESCUE COORDINATION CENTER
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.
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
RESTRICTED AREA
(See SPECIAL USE AIRSPACE.)
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 which are applicable to 14 CFR Section 91.117.
RESUME OWN NAVIGATION
Used by ATC to advise a pilot to resume his/her 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. (See RADAR CONTACT LOST.) (See RADAR SERVICE TERMINATED.)
RMI
(See RADIO MAGNETIC INDICATOR.)
RNAV
(See AREA NAVIGATION.)
RNAV APPROACH
An instrument approach procedure which relies on aircraft area navigation equipment for navigational guidance. (See AREA NAVIGATION.) (See INSTRUMENT APPROACH PROCEDURE.)
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 10 NM to 30 NM and an altitude range of 500 feet to 10,000 feet AGL.
ROGER
I have received all of your last transmission. It should not be used to answer a question requiring a yes or a no answer.
(See AFFIRMATIVE.) (See NEGATIVE.)
ROLLOUT RVR
(See VISIBILITY.)
ROUTE
A defined path, consisting of one or more courses in a horizontal plane, which aircraft traverse over the surface of the earth. (See AIRWAY.) (See JET ROUTE.) (See PUBLISHED ROUTE.) (See UNPUBLISHED ROUTE.)
ROUTE ACTION NOTIFICATION
URET notification that a PAR/PDR/PDAR has been applied to the flight plan. (See ATC PREFERRED ROUTE NOTIFICATION.) (See USER REQUEST EVALUATION TOOL.)
ROUTE SEGMENT
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. (See FIX.) (See ROUTE.)
RSA
(See RUNWAY SAFETY AREA.)
RTR
(See REMOTE TRANSMITTER/RECEIVER.)
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, Runway 25. (See PARALLEL RUNWAYS.)
RUNWAY CENTERLINE LIGHTING
(See AIRPORT LIGHTING.)
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. (See BRAKING ACTION.)
RUNWAY END IDENTIFIER LIGHTS (REIL)
(See AIRPORT LIGHTING.)
RUNWAY GRADIENT
The average slope, measured in percent, between two ends or points on a runway. Runway gradient is depicted on Government aerodrome sketches when total runway gradient exceeds 0.3%.
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., Runway 4, actual magnetic heading of the runway centerline 044, fly 044.
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 which 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 LIGHTS
(See AIRPORT LIGHTING.)
RUNWAY MARKINGS
(See AIRPORT MARKING AIDS.)
RUNWAY 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 en route structure to the point where the pilot will receive clearance for and execute an instrument approach procedure. A Runway Profile Descent may 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 AC 150/5300-13, Airport Design, Chapter 3. Figure 3-1 in AC 150/5300-13 depicts the RSA. 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 firefighting 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 TRANSITION
- a. Conventional STARs/SIDs. The portion of a STAR/SID that serves a particular runway or runways at an airport.
- b. RNAV STARs/SIDs. Defines a path(s) from the common route to the final point(s) on a STAR. For a SID, the common route that serves a particular runway or runways at an airport.
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 which is 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 14 CFR Section 91.129.
- b. Informal Runway Use Program- An approved noise abatement program which does not require a Letter of Understanding, and participation in the program is voluntary for aircraft operators/pilots.
RUNWAY VISIBILITY VALUE
(See VISIBILITY.)
RUNWAY VISUAL RANGE
(See VISIBILITY.)
