International Standards for Rules of the Air Definitions

Question 1

Acrobatic flight

Answer 1

Manoeuvres intentionally performed by an aircraft involving an abrupt change in its attitude, an abnormal attitude, or an abnormal variation in speed.

Question 2

AD S-C agreement

Answer 2

A reporting plan which establishes the conditions of ADS-C data reporting (i.e. data required by the air traffic services unit and frequency of ADS-C reports which have to be agreed to prior to using ADS-C In the provision of air traffic services).

Note - The terms of the agreement will be exchanged between the ground system and the aircraft by means of a contract, or a series of contracts

Question 3

Advisory airspace.

Answer 3

An airspace of defined dimensions, or designated route, within which airtraffic advisory service is available.

Question 4

Advisory route.

Answer 4

A designated route along which airtraffic advisory service is available.

Question 5

Aerodrome.

Answer 5

defined area on land or water (including any buildings, installations and equipment) intended to be used either wholly or in part for the arrival, departure and surface movement of aircraft.

Question 6

Aerodrome control service.

Answer 6

Air traffic control service for aerodrome traffic.

Question 7

Aerodrome control tower.

Answer 7

A unit established to provide airtraffic control service to aerodrome traffic.

Question 8

Aerodrome traffic.

Answer 8

All traffic on the manoeuvring area of an aerodrome and all aircraft flying In the vicinity of an aerodrome.

Note - An aircraft is In the vicinity of an aerodrome when it is in, entertng or leaving an aerodrome traffic circuit.

Question 9

Aerodrome traffic zone.

Answer 9

An airspace of defined dimensions established around an aerodrome for the protection of aerodrome traffic.

Question 10

Aerodrome information management (AIM).

Answer 10

The dynamic, integrated management of aeronautical information through the provision and exchange of quality-assured digital aeronautical data in collaboration with all parties.
Advisory route. A designated route along which airtraffic advisory service is available.

Question 11

Aeronautical information Publication (AIP). A publication Issued by or with the authority of a State and containing aeronautical Information of a lasting character essential to air navigation.

Question 12

Aeronautical station. A land station In the aeronautical mobile service. In certain instances, an aeronautical station may be located, for example, on board ship or on a platform at sea.

Question 13

Aeroplane. A power-driven heavier-than-alr aircraft, deriving Its lift In flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight.

Question 14

Airborne collision avoidance system (ACAS). An aircraft system based on secondary surveillance radar (SSR) transponder signals which operates independently of ground-based equipment to provide advice to the pilot on potential conflicting aircraft that are equipped with SSR transponders.

Question 15

Aircraft Any machine that can derive support In the atmosphere from the reactions of the air other than the reactions of the air against the earth’s surface.

Question 16

Air-ground control radio station. An aeronautical telecommunication station having primary responsibility for handling communications pertaining to the operation and control of aircraft In a given area

Question 17

Air-taxing. Movement of a helicopter/VTOL above the surface of an aerodrome, normally In ground efTect and at a ground speed normally less than 37 km/h (20 kt).

Answer 17

Note - Tie actual height may vary, and some helicopters may require air-taxiing above 8 m (25 ft) AGL to reduce ground effect turbulence or provide clearance for cargo slingloads.

Question 18

Air traffic.

Answer 18

All aircraft in flight or operating on the manoeuvring area of an aerodrome.

Question 19

Air traff c advisory service. A service provided within advisory airspace to ensure separation, in so far as practical, between aircraft which are operating on IFR flight plans.

Question 20

Air traffic control clearance. Authorization for an aircraft to proceed under conditions specified by an air traffic control unit.

Answer 20

Note 1.- For convenience, the term “air traffic control clearance’ Is frequently abbreviated to “clearance’ when used In approortate contexts.
Note 2.- The abbreviated term “clearance’ may be prefixed by the words “taxi’, “take-off, “departure”, “en route’, “approach” or “landing* to indicate the particular portion of flight to which the air traffic control clearance relates.

Question 21

Air traffic control service.

Answer 21

A service provided for the purpose of:
a) preventing collisions
1) between aircraft and
2) on the manoeuvring area between aircraft and obstructions and
b) expediting and maintaining an orderly flow of air traffic.

Question 22

Air traffic control unit. A generic term meaning variously, area control centre, approach control unit or aerodrome control tower.

Question 23

Air traffic service (ATS). A generic term meaning variously, flight information service, alerting service, air traffic advisory service, air traffic control service (area control service, approach control service or aerodrome control service).

Question 24

Air traffic services airspaces. Airspaces of defined dimensions, alphabetically designated, within which specific types of flights may operate and for which ATS and rules of operation are specified.

Answer 24

Note - ATS airspaces are classified as Class A to G.

Question 25

Air traffic services reporting office. A unit established for the purpose of receiving reports concerning air traffic services and flight plans submitted before departure.

Answer 25

Note - An air traffic services reporting office may be established as a separate unit or combined with an existing unit, such as another air traffic services unit, or a unit of the aeronautical information service.

Question 26

Air traffic services unit. A generic term meaning variously, air traffic control unit, flight Information centre or air traffic services reporting office

Question 27

Airway. A control area or portion thereof established In the form of a corridor.

Question 28

Alerting service. A service provided to notify appropriate organizations regarding aircraft In need of search and rescue aid, and assist such organizations as required.

Question 29

Alternate aerodrome. 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 where the necessary services and facilities are available, where aircraft performance requirements can be met and which Is operational at the expected time of use. Alternate aerodromes include the following

Question 30

Take-off alternate. An alternate aerodrome at which an aircraft would be able to land should this become necessary shortly after take-off and It is not possible to use the aerodrome of departure.

Question 31

En-route alternate. An alternate aerodrome at which an aircraft would be able to land In the event that a diversion becomes necessary while en route.

Question 32

Destination alternate. An alternate aerodrome at which an aircraft would be able to land should It become either impossible or inadvisable 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.

Question 33

Altitude. The vertical distance of a level, a point or an object considered as a point, measured from mean sea level (MSL).

Question 34

Approach control service. Air traffic control service for arriving or departing controlled flights.

Question 35

Approach control unit. A unit established to provide air traffic control service to controlled flights arriving at, or departing from, one or more aerodromes.

Question 36

Appropriate ATS authority. The relevant authority designated by the State responsible for providing air traffic services In the airspace concerned.

Question 37

Appropriate authority.
a) Regarding flight over the high seas: The relevant authority of the State of Registry.
b) Regarding flight other than over the high seas: The relevant authority of the State having sovereignty over the territory being overflown.

Question 38

Apron. A defined area, on a land aerodrome, Intended to accommodate aircraft for purposes of loading or unloading passengers, mall or cargo, fuelling, parking or maintenance

Question 39

Area control centre. A unit established to provide air traffic control service to controlled flights In control areas under its jurisdiction

Question 40

Area control service. Air traffic control service for controlled flights In control areas

Question 41

Area navigation (RNAV). A method of navigation which permits aircraft operation on any desired flight path within the coverage of ground- or space-based navigation aids or within the limits of the capability of self-contained aids, or a combination of these.
Note. - Area navigation includes performance-based navigation as well as other operations that do not meet the definition of performance-based navigation

Question 42

ATS route. A specified route designed for channelling the flow of traffic as necessary for the provision of air traffic services.
Note 1. - The term “ATS route” Is used to mean variously, airway, advisory route, controlled or uncontrolled route, arrival or departure route, etc.
Note 2. - An ATS route Is defined by route specifications which Include an ATS route designator, the track to or from significant points (waypoints), distance between significant points, reporting requirements and, as determined by the appropriate ATS authority, the lowest safe altitude.

Question 43

Automatic dependent surveillance - contract (ADS-C). A means by which the terms of an ADS-C agreement will be exchanged between the ground system and the aircraft, via a data link, specifying under what conditions ADS-C reports would be initiated, and what data would be contained in the reports.

Answer 43

Note. - The abbreviated term “ADS contract” is commonly used to refer to ADS event contract, ADS demand contract ADS periodic contract or an emergency mode.

Question 44

Ceiling. The height above the ground or water of the base of the lowest layer of cloud below 6000 metres (20 000 feet) covering more than half the sky.

Question 45

Changeover point The point at which an aircraft navigating on an ATS route segment defined by reference to very high frequency omnidirectional radio ranges Is expected to transfer Its primary navigational reference from the facility behind the aircraft to the next facility ahead of the aircraft.
Note. - Changeover points are established to provide the optimum balance in respect of signal strength and quality the same portion of a route segment

Question 46

Clearance limit The point to which an aircraft Is granted an air traffic control clearance.

Question 47

Command and control (C2) link. The data link between the remotely piloted aircraft and the remote pilot station for the purposes of managing the flight.

Question 48

Control area. A controlled airspace extending upwards from a specified limit above the earth.

Question 49

Controlled aerodrome. An aerodrome at which air traffic control service Is provided to aerodrome traffic.

Answer 49

Note. - The term ‘controlled aerodrome” Indicates that air traffic control service Is provided to aerodrome traffic but does not necessarily imply that a control zone exists.

Question 50

Controlled airspace. An airspace of defined dimensions within which air traffic control service is provided In accordance with the airspace classification.

Answer 50

Note. - Controlled airspace Is a generic term which covers ATS airspace Classes A. B, C, D and E as descrtbed in Annex 11.

Question 51

Controlled flight Any flight which Is subject to an air traffic control clearance.

Question 52

Controller-pilot data link communications (CPDLC). A means of communication between controller and pilot using data link for ATC communications.

Question 53

Control zone. A controlled airspace extending upwards from the surface of the earth to a specified upper limit

Question 54

Cruise climb. An aeroplane cruising technique resulting in a net increase in altitude as the aeroplane mass decreases

Question 55

Cruising level. A level maintained dunng a significant portion of a flight.

Question 56

Current flight plan. The flight plan, including changes. If any. brought about by subsequent clearances.

Question 57

Danger area. An airspace of defined dimensions within which activities dangerous to the flight of aircraft may exist at speciled times

Question 58

Data link communications. A form of communication intended for the exchange of messages via a data link

Question 59

Detect and avoid. The capability to see, sense or detect conflicting traffic or other hazards and take the approphate action.

Question 60

Estimated off-block time. (CODT) The estimated time at which the aircraft will commence movement associated with departure.

Question 61

Estimated time of arrival. For IFR flights, the time at which It is estimated that the aircraft will amve over that designated point, defined by reference to navigation aids, from which It Is Intended that an instrument approach procedure will be commenced, or, if no navigation aid Is associated with the aerodrome, the time at which the aircraft will arrive over the aerodrome. For VFR flights, the time at which It is estimated that the aircraft will arrtve over the aerodrome.

Question 62

Expected approach time. The time at which ATC expects that an arriving aircraft, following a delay, will leave the holding fix to complete Its approach for a landing.

Answer 62

Note. - The actual time of leaving the holding fix will depend upon the approach clearance.

Question 63

Filed flight plan. The flight plan as filed with an ATS unit by the pilot or a designated representative, without any subsequent changes.

Question 64

Flight crew member. A licensed crew member charged with duties essential to the operation of an aircraft during a flight duty period.

Question 65

Flight information centre. A unit established to provide flight information service and alerting service.

Question 66

Flight irformation region. An airspace of defined dimensions within which flight information service and alerting service are provided.

Question 67

Flight irformation service. A service provided for the purpose of giving advice and Information useful for the safe and efficient conduct of flights.

Question 68

Flight level. A surface of constant atmospheric pressure which Is related to a specific pressure datum. 1013.2 hectopascals (hPa), and is separated from other such surfaces by specific pressure Intervals.
Note 1 - A pressure type altimeter calibrated In accordance with the Standard Atmosphere:
a) when set to a QNH altimeter setting, will indicate altitude
b) when set to a QFE altimeter setting, will indicate height above the QFE reference datum
c) when set to a pressure of 1013.2 hPa, may be used to indicate flight levels
Note 2. - The terms ‘height” and “altitude”, used In Note 1 above, Indicate altimetrtc rather than geometric heights and altitudes.

Question 69

Flight plan. Specified information provided to airtrafflc services units, relative to an intended flight or portion of a flight of an aircraft.

Question 70

Flight plan. Specified information provided to airtrafflc services units, relative to an intended flight or portion of a flight of an aircraft.

Question 71

Flight visibility. The visibility forward from the cockpit of an aircraft In flight

Question 72

Ground visibility. The visibility at an aerodrome as reported by an accredited observer or by automatic systems.

Question 73

Heading. The direction in which the longitudinal axis of an aircraft Is pointed, usually expressed in degrees from North (true, magnetic, compass or grid).

Question 74

Height. The vertical distance of a level, a point or an object considered as a point, measured from a specified datum.

Question 75

IFR. The symbol used to designate the instrument flight rules.

Question 76

IFR flight. A flight conducted in accordance with the Instrument flight rules.

Question 77

IMC. The symbol used to designate instrument meteorological conditions.

Question 78

Instrument approach operations. An approach and landing using instruments for navigation guidance based on an instrument approach procedure. There are two methods for executing instrument approach operations:
a) a two-dimensional (2D) instrument approach operation, using lateral navigation guidance only and
b) a three-dimensional (3D) instrument approach operation, using both lateral and vertical navigation guidance. Note. - Lateral and vertical navigation guidance refers to the guidance provided either by:
a) a ground-based radio navigation aid or
b) computer-generated navigation data from ground-based, space-based, self-contained navigation aids or a combination of these.

Question 79

Instrument approach procedure. A series of predetermined manoeuvres by reference to flight Instruments with specified protection from obstacles from the initial approach fix, or where applicable, from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, If a landing is not completed, to a position at which holding or en-route obstacle clearance criteria apply. Instrument approach procedures are classified as follows:

Question 80

Non-precision approach (NPA) procedure. An Instrument approach procedure designed for 2D Instrument approach operations Type A.
Note. - Non-precision approach procedures may be flown using a continuous descent final approach (CDFA) technique. CDFAs with advisory VNAV guidance calculated by on-board equipment (see PANS-OPS (Doc 8168), Volume I, Part I, Section 4. Chapter 1, paragraph 1.8.1) are considered 3D instrument approach operations.
CDFAs with manual calculation of the required rate of descent are considered 2D instrument approach operations. For more information on CDFAs, refer to PANS-OPS (Doc 8168) Volume I, Part I, Section 4, Chapter 1, paragraphs 1.7 and 1.8.

Question 81

Approach procedure with vertical guidance (APV). A performance-based navigation (PBN) instrument approach procedure for 3D Instrument approach operations Type A.

Question 82

Precision approach (PA) procedure. An instrument approach procedure based on navigation systems (ILS, MLS, GLS and SBAS Cat I) designed for 3D instrument approach operations Type A or B.

Answer 82

Note - Refer to Annex 6 for instrument approach operation types.

Question 83

Instrument meteorological conditions. Meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling, less than the minima specified forvisual meteorological conditions.

Answer 83

Note.-Tie specified minima forvisual meteorological conditions are contained in Lesson 8.

Question 84

Landing area. That part of a movement area intended for the landing or take-off of aircraft.

Question 85

Level. A generic term relating to the vertical position of an aircraft in flight and meaning vanously. height, altitude or flight level.

Question 86

Manoeuvring area. That part of an aerodrome to be i aprons.
I for the take-off, landing and taxiing of aircraft, excluding

Question 87

Movement area. That part of an aerodrome to be used for the take-off, landing and taxiing of aircraft, consisting of the manoeuvring area and the apron(s).

Question 88

Operator. A person, organization or enterprise engaged in or offering to engage In an aircraft operation.
Note. - In the context of remotely piloted aircraft, an aircraft operation includes the remotely piloted aircraft system.

Question 89

Pllot-in-command. The pilot designated by the operator, or In the case of general aviation, the owner, as being in command and charged with the safe conduct of a flight

Question 90

Pllot-in-command. The pilot designated by the operator, or In the case of general aviation, the owner, as being in command and charged with the safe conduct of a flight

Question 91

Pressure-altitude. An atmospheric pressure expressed in terms of altitude which corresponds to that pressure In the Standard Atmosphere.

Question 92

roblematic use of substances. The use of one or more psychoactive substances by aviation personnel in a way that
a) constitutes a direct hazard to the user or endangers the lives, health or welfare of others and/or
b) causes or worsens an occupational, social, mental or physical problem or disorder

Question 93

Prohibited area. An airspace of defined dimensions, above the land areas or territorial waters of a State, within which the flight of aircraft Is prohibited

Question 94

Psychoactive substances. Alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens, and volatile solvents, whereas coffee and tobacco are excluded.

Question 95

Radiotelephony. A form of radio communication pnmartly intended for the exchange of Information in the form of speech.

Question 96

Remote pilot. A person charged by the operator with duties essential to the operation of a remotely piloted aircraft and who manipulates the night controls, as appropriate, during flight time.

Question 97

Remote pilot station. The component of the remotely piloted aircraft system containing the equipment used to pilot the remotely piloted aircraft.

Question 98

Remotely piloted aircraft (RPA). An unmanned aircraft which Is piloted from a remote pilot station.

Question 99

Remotely piloted aircraft system (RPAS). A remotely piloted aircraft. Its associated remote pilot statlon(s). the required command and control links and any other components as specified In the type design.

Question 100

Repetitive flight plan (RPL). A flight plan related to a series of frequently recurring, regularly operated individual flights with identical basic features, submitted by an operator for retention and repetitive use by ATS units.

Question 101

Reporting point. A specified geographical location in relation to which the position of an aircraft can be reported.

Question 102

Restricted area. An airspace of defined dimensions, above the land areas orterrltortal waters of a State, within which the flight of aircraft Is restricted in accordance with certain specified conditions.

Question 103

RPA observer. A trained and competent person designated by the operator who, by visual observation of the remotely piloted aircraft, assists the remote pilot in the safe conduct of the night

Question 104

Runway. A defined rectangular area on a land aerodrome prepared forthe landing and take-off of aircraft.

Question 105

Runway-holding position. A designated position intended to protect a runway, an obstacle limitation surface, or an ILS/MLS critical/sensitive area at which taxiing aircraft and vehicles shall stop and hold, unless otherwise authorized by the aerodrome control tower.
Note.- Ir radlotelephony phraseologies, the expression ‘holding point’ is used to designate the runway-holding position.

Question 106

Safety-sensitive personnel. Persons who might endanger aviation safety if they perform their duties and functions Improperly Including, but not limited to, crew members, aircraft maintenance personnel and air traffic controllers.

Question 107

Signal area. An area on an aerodrome used for the display of ground signals.

Question 108

Special VFR flight. A VFR flight cleared by air traffic control to operate within a control zone in meteorological conditions below VMC.

Question 109

Taxiing. Movement of an aircraft on the surface of an aerodrome under Its own power, excluding take-off and landing.

Question 110

Taxiway. A defined path on a land aerodrome established for the taxiing of aircraft and intended to provide a link
between one part of the aerodrome and another, including:
a) Aircraft stand taxllane. A portion of an apron designated as a taxiway and intended to provide access to aircraft stands only.
b) Apron taxiway. A portion of a taxiway system located on an apron and intended to provide a through taxi route across the apron.
c) Rapid exit taxiway. A taxiway connected to a runway at an acute angle and designed to allow landing aeroplanes to turn off at higher speeds than are achieved on other exit taxiways thereby minimizing runway occupancy times.

Question 111

Terminal control area. A control area normally established at the confluence of ATS routes in the vicinity of one or
more major aerodromes.

Question 112

Total estimated elapsed time. For IFR flights, the estimated time required from take-off to arrive over that designated point, defined by reference to navigation aids, from which It is Intended that an Instrument approach procedure will be commenced, or. If no navigation aid is associated with the destination aerodrome, to arrive over the destination aerodrome. For VFR flights, the estimated time required from take-off to arrive over the destination aerodrome.

Question 113

Track. The projection on the earth’s surface of the path of an aircraft, the direction of which path at any point Is usually expressed in degrees from North (true, magnetic or grid).

Question 114

Traffic avoidance advice. Advice provided by an air traffic services unit specifying manoeuvres to assist a pilot to avoid a collision.

Question 115

Traffic information. Information issued by an air traffic services unit to alert a pilot to other known or observed air traffic which may be in proximity to the position or Intended route of flight and to help the pilot avoid a collision.

Question 116

Transition altitude. The altitude at or below which the vertical position of an aircraft Is controlled by reference to altitudes.

Question 117

Unmanned free balloon. A non-power-driven, unmanned, lighter-than-air aircraft in free flight.

Question 118

VFR. The symbol used to designate the visual flight rules.

Question 119

VFR flight. A flight conducted in accordance with the visual flight rules

Question 120

Visibility. Visibility for aeronautical purposes is the greater of:
a) the greatest distance at which a black object of suitable dimensions, situated near the ground, can be seen and recognized when observed against a bright background
b) the greatest distance at which lights In the vicinity of 1 000 candelas can be seen and identified against an unlit background.
Note 1. - The two distances have different values In air of a given extinction coefficient, and the latter b) varies with the background Illumination. The former a) Is represented by the meteorological optical range (MOR).
Note. 2. - The definition applies to the observations of visibility in local routine and special reports, to the observations of prevailing and minimum visibility reported In METAR and SPECI and to the observations of ground visibility.

Question 121

Visual line-of-sight (VLOS) operation. An operation In which the remote pilot or RPA observer maintains direct unaided visual contact with the remotely piloted aircraft

Question 122

Visual meteorological conditions. Meteorological conditions expressed In terms of visibility, distance from cloud, and celling, equal to or better than specified minima.
Note. - The specified minima are contained in Lesson 8.