A
ACCELERATE STOP DISTANCE AVAILABLE (ASDA)
The length of the takeoff run available plus the length of the stopway, if provided.
ADEQUATE VIS REF (Adequate Visual Reference)
Runway markings or runway lighting that provides the pilot with adequate visual reference to continuously identify the takeoff surface and maintain directional control throughout the takeoff run.
ADVISORY ROUTE (ADR)
A designated route along which air traffic advisory service is available.
NOTE: Air traffic control service provides a much more complete service than air traffic advisory service; advisory areas and routes are therefore not established within controlled airspace, but air traffic advisory service may be provided below and above control areas.
ADVISORY SERVICE
Advice and information provided by a facility to assist pilots in the safe conduct of flight and aircraft movement.
AERODROME FLIGHT INFORMATION SERVICE (AFIS)
A directed traffic information and operational information service provided within an aerodrome flight information zone, to all radio equipped aircraft, to assist in the safe and efficient conduct of flight.
AERODROME REFERENCE CODE
A simple method for interrelating the numerous specifications concerning the characteristics of aerodromes so as to provide a series of aerodromes facilities that are suitable for the aeroplanes that are intended to operate at the aerodrome. The aerodrome reference code — code number and letter, which are selected for aerodrome planning purposes, have the meanings assigned to them as indicated in the table below:
NOTE: Guidance on planning for aeroplanes with wing spans greater than 80m is given in the ICAO Doc. 9157 “Aerodrome Design Manual,” Parts 1 and 2.
AERODROME TRAFFIC FREQUENCY (ATF)
A frequency designated at an uncontrolled airport. An ATF is used to ensure all radio equipped aircraft operating within the area, normally within a 5 NM radius of the airport, are listening on a common frequency. The ATF is normally the ground station frequency. Where a ground station does not exist, a common frequency is designated. Radio call sign is that of the ground station, or where no ground station exists, a broadcast is made with the call sign “Traffic Advisory.” Jeppesen charts list the frequency and the area of use when other than the standard 5 NM.
AERODROME TRAFFIC ZONE (ATZ)
An airspace of detailed dimensions established around an aerodrome for the protection of aerodrome traffic.
AERONAUTICAL RADIO, INCORPORATED (ARINC)
An international radio network providing air-to-ground communications available on a subscription (fee) basis.
AIRCRAFT APPROACH CATEGORY (USA TERPS)
A grouping of aircraft based on a speed of Vref, if specified, or if Vref is not specified, 1.3 VS0 at the maximum certificated landing weight. Vref, VS0, and the maximum certificated landing weight are those values as established for the aircraft by the certification authority of the country of registry. An aircraft shall fit in only one category. If it is necessary to maneuver at speeds in excess of the upper limit of a speed range for a category, the minimums for the ext higher category should be used. For example, an aircraft which falls in Category A, but is circling to land at a speed in excess of 91 knots, should use the approach Category B minimums when circling to land. The categories are as follows:
Category A—Speed less than 91 knots.
Category B — Speed 91 knots or more but less than 121 knots.
Category C—Speed 121 knots or more but less than 141 knots.
Category D—Speed 141 knots or more but less than 166 knots.
Category E—Speed 166 knots or more.
NOTE: Category E includes only certain Military
Aircraft and is not included on Jeppesen Approach Charts.
AIRCRAFT APPROACH CATEGORY (ICAO)
The following ICAO table indicates the specified range of handling speeds (IAS in Knots) for each category of aircraft to perform the maneuvers specified. These speed ranges have been assumed for use in calculating airspace and obstacle clearance for each procedure.
Vat —Speed at threshold based on 1.3 times stall speed in the landing configuration at maximum certificated landing mass.
*Maximum speed for reversal and racetrack procedures.
Category E contains only certain Military Aircraft and is not included on Jeppesen Approach Charts.
NOTE: The speed table applies to the new ICAO approach procedures which are identifiable by the OCA(H) figures and the PANS OPS notation on the lower left corner of the approach chart. Old ICAO approach procedures show an OCL instead of OCA(H). Deviations are listed in the Air Traffic Control section.
AIR DEFENSE IDENTIFICATION ZONE
The area of airspace over land or water, extending upward from the surface, within which the ready identification, the location, and the control of aircraft are required in the interest of national security.
AIRPORT ELEVATION/FIELD ELEVATION
The highest point of an airports usable runways measured in feet from mean sea level. In a few countries, the airport elevation is determined at the airport reference point.
AIRPORT REFERENCE POINT (ARP)
A point on the airport designated as the official airport location.
AIRPORT SURVEILLANCE RADAR (ASR)
Approach control radar used to detect and display an aircraft’s position in the terminal area. ASR provides range and azimuth information but does not provide elevation data. Coverage of the ASR can extend up to 60 miles.
AIR TRAFFIC CONTROL CLEARANCE
An authorization by air traffic control, for the purpose of preventing collision between known aircraft, for an aircraft to proceed under specified traffic conditions within controlled airspace.
AIR TRAFFIC CONTROL ASSIGNED AIRSPACE (ATCAA)
Airspace of defined vertical/lateral limits, assigned by ATC, for the purpose of providing air traffic segregation between the specified activities being conducted within the assigned airspace and other IFR air traffic.
AIRWAY (ICAO)
A control area or portion thereof established in the form of a corridor equipped with radio navigation aids.
AIRWAY (USA)
A Class E airspace area established in the form of a corridor, the centerline of which is defined by radio navigational aids.
ALONG TRACK DISTANCE
The distance measured from a point-in-space by systems using area navigation reference capabilities that are not subject to slant range errors.
ALTERNATE AERODROME (ICAO)
An aerodrome to which an aircraft may proceed when it becomes either impossible or inadvisable to proceed to or to land at the aerodrome of intended landing.
NOTE: The aerodrome from which a flight departs may also be an en route or a destination alternate aerodrome for that flight.
ALTERNATE AIRPORT (USA)
An airport at which an aircraft may land if a landing at the intended airport becomes inadvisable.
ALTIMETER SETTING
The barometric pressure reading used to adjust a pressure altimeter for variations in existing atmospheric pressure or to the standard altimeter setting (29.92 inches of mercury, 1013.2 hectopascals or 1013.2 millibars).
ALTITUDE (ICAO)
The vertical distance of a level, a point, or an object considered as a point, measured from Mean Sea Level (MSL).
ALTITUDE (USA)
The height of a level, point or object measured in feet Above Ground Level (AGL) or from Mean Sea Level (MSL).
AGL Altitude – Altitude expressed in feet measured above ground level (QFE).
MSL Altitude – Altitude expressed in feet measured from mean sea level (QNH).
Indicated Altitude – The Altitude as shown by an altimeter. On a pressure barometric altimeter it is altitude as shown uncorrected for instrument error and uncompensated for variation from standard atmospheric conditions.
AREA NAVIGATION/RNAV
A method of navigation that permits aircraft operations on any desired course within the coverage of station referenced navigation signals or within the limits of self contained system capability.
ARRIVAL ROUTES (ICAO)
Routes on an instrument approach procedure by which aircraft may proceed from the en route phase of flight to the initial approach fix.
ATS ROUTE
A specified route designated for channeling the flow of traffic as necessary for the provision of air traffic services.
NOTE: The term “ATS Route” is used to mean variously, airway, advisory route, controlled or uncontrolled route, arrival or departure route, etc.
AUTOMATIC DEPENDENT SURVEILLANCE (ADS)
A surveillance technique, in which aircraft automatically provide, via a data link, data derived from on-board navigation and position fixing systems, including aircraft identification, four-dimensional position and additional data as appropriate.
AUTOMATED SURFACE OBSERVATION SYSTEM (ASOS)
The Automated Surface Observation System, in the United States, is a surface weather observing system implemented by the National Weather Service, the Federal Aviation Administration and the Department of Defense. It is designed to support aviation operations and weather forecast activities. The ASOS provides continuous minute-byminute observations and performs the basic observing functions necessary to generate an aviation routine weather report (METAR) and other aviation weather information. ASOS information may be transmitted over a discrete VHF radio frequency or the voice portion of a local NAVAID.
AUTOMATED WEATHER OBSERVING SYSTEM (AWOS)
An automated weather reporting system which transmits local real-time weather data directly to the pilot.
AWOS-1 Usually reports altimeter setting, wind data, temperature, dewpoint and density altitude.
AWOS-2 Reports same as AWOS-1 plus visibility.
AWOS-3 Reports the same as AWOS-2 plus cloud/ceiling data.
B
BRAKING ACTION (GOOD, FAIR, POOR, NIL)
A report of conditions on the airport movement area providing a pilot with a degree/quality of braking that might be expected. Braking action is reported in terms of good, fair, poor, or nil.
C
CARDINAL ALTITUDES OR FLIGHT LEVELS
“Odd” or “Even” thousand-foot altitudes or flight levels; e.g., 5000, 6000, 7000, FL60, FL250, FL260, FL270.
CEILING (ICAO)
The height above the ground or water of the base of the lowest layer of cloud below 6000 meters (20,000 feet) covering more than half
the sky.
CEILING (USA)
The height above the earths surface of the lowest layer of clouds or obscuring phenomena that is reported as “broken”, “overcast”, or “obscuration”, and not classified as “thin”, or “partial”.
CHART NOTAMS
Jeppesen Chart NOTAMs include significant information changes affecting Enroute, Area, and Terminal charts. Entries are published until the temporary condition no longer exists, or until the permanent change appears on revised charts. Enroute chart numbers / panel numbers / letters and area chart identifiers are included for each entry in the enroute portion of the chart NOTAMs. To avoid duplication of information in combined Enroute and Terminal Chart NOTAMs, navaid conditions, except for ILS components, are listed only in the Enroute portion of the Chart NOTAMs. All times are local unless otherwise indicated. Arrows indicate new or revised information. Chart NOTAMs are only an abbreviated service. Always ask for pertinent NOTAMs prior to flight.
COMMON TRAFFIC ADVISORY FREQUENCY (CTAF) (USA)
A frequency designed for the purpose of carrying out airport advisory practices while operating to or from an uncontrolled airport. The CTAF may be a UNICOM, Multicom, FSS, or tower frequency.
COMMUNITY AERODROME RADIO STATION (CARS)
An aerodrome radio that provides weather, field conditions, accepts flight plans and position reports.
COMPULSORY REPORTING POINTS
Reporting points which must be reported to ATC. They are designated on aeronautical charts by solid triangles or filed in a flight plan as fixes selected to define direct routes. These points are geographical locations which are defined by navigation aids/fixes. Pilots should discontinue position reporting over compulsory reporting points when informed by ATC that their aircraft is in “radar contact.”
CONDITIONAL ROUTES (CDR) (Europe)
Category 1,2,3.
Category 1: Permanently plannable CDR during designated times.
Category 2: Plannable only during times designated in the Conditional Route Availability Message (CRAM) published at 1500Z for the 24 hour period starting at 0600Z the next day.
Category 3: Not plannable. Usable only when directed by ATC.
CONTROL AREA (ICAO)
A controlled airspace extending upwards from a specified limit above the earth.
CONTROLLED AIRSPACE
An airspace of defined dimensions within which air traffic control service is provided to IFR flights and to VFR flights in accordance with the airspace classification.
NOTE: Controlled airspace is a generic term which covers ATS airspace Classes A, B, C, D, and E.
CONTROL ZONE (ICAO)
A controlled airspace extending upwards from the surface of the earth to a specified upper limit.
COURSE
The intended direction of flight in the horizontal plane measured in degrees from north.
The ILS localizer signal pattern usually specified as front course or back course.
The intended track along a straight, curved, or segmented MLS path.
CRITICAL HEIGHT
Lowest height in relation to an aerodrome specified level below which an approach procedure cannot be continued in a safe manner solely by the aid of instruments.