[{"term":"\"Operations normal\"","definition":"Routine report showing the flight is progressing to plan.","source":"SERA.10001(b)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"},"anchor":"letter-\""},{"term":"A-SMGCS / SMR","definition":"Surface surveillance systems that the tower uses to monitor and guide surface traffic.","source":"ATS.TR.245","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"},"anchor":"letter-A"},{"term":"ACAS","definition":"Airborne collision avoidance system using SSR transponder signals.","source":"SERA Art. 2(17)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"ACAS resolution advisory (RA)","definition":"Collision-avoidance manoeuvre indication that the pilot follows even against ATC.","source":"SERA.11014","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"access control","definition":"Applying means by which entry of unauthorised persons or vehicles may be prevented.","source":"Reg. (EC) No 300/2008 Art. 3(10)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"accident","definition":"Occurrence in the boarding-to-disembarkation window that causes a fatal or serious injury, qualifying damage, or a missing or inaccessible aircraft.","source":"Reg. (EU) No 996/2010 Art. 2(1)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"accredited representative","definition":"Qualified person designated by a State to take part in an investigation run by another State.","source":"Reg. (EU) No 996/2010 Art. 2(2)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"act of unlawful interference","definition":"A deliberate act that jeopardises the security of civil aviation. The regulation uses the term without defining it.","source":"Reg. (EC) No 300/2008 Art. 1, Art. 3","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"ADS-B","definition":"Broadcast of position and other data from the aircraft (may share the Mode S transmitter).","source":"SERA Appendix 6 Item 10; Appendix 1 note to 2.3.10","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Advisory airspace / advisory route","definition":"Airspace or a route where air traffic advisory service is available","source":"SERA Article 2(3), (4)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"AeMC / AME / GMP","definition":"Aero-medical centre / aero-medical examiner / general medical practitioner (may issue LAPL medicals where national law allows).","source":"MED.A.040","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"aerobatic flight","definition":"Intentional manoeuvres with abrupt attitude change, abnormal attitude or abnormal speed variation, not needed for normal flight or for licence/rating instruction (except aerobatic rating).","source":"SERA Article 2(5)","page":{"id":"010-05-02","title":"Rules of the air: general rules","url":"/010-air-law/05-rules-of-the-air/02-rules-of-the-air-general-rules/"}},{"term":"aerodrome","definition":"A defined area on land or water (or on a structure), with its buildings and equipment, intended for arrival, departure and surface movement of aircraft.","source":"SERA Article 2(6)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"aerodrome beacon","definition":"Aeronautical beacon used to indicate the location of an aerodrome from the air.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"aerodrome control service","definition":"ATC service for aerodrome traffic.","source":"SERA Art. 2(7)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"aerodrome control tower (TWR)","definition":"Unit providing ATC to aerodrome traffic.","source":"SERA Art. 2(8)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"aerodrome elevation","definition":"Elevation of the highest point of the landing area.","source":"CS ADR-DSN.A.002; Annex 14 Ch. 1","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"aerodrome emergency plan (AEP)","definition":"The aerodrome operator's plan that coordinates all organisations responding to an emergency at or near the aerodrome.","source":"ADR.OPS.B.005","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"Aerodrome identification sign","definition":"ICAO-recommended sign showing the aerodrome name, readable from the air.","source":"Annex 14 5.4.5","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"Aerodrome reference point (ARP)","definition":"The designated geographical location of an aerodrome, near its (planned) geometric centre.","source":"Annex 14 Ch. 1; GM1 ADR.OPS.A.005","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"Aerodrome reference temperature","definition":"Monthly mean of daily maximum temperatures of the hottest month, averaged over five years, in °C.","source":"GM1 ADR.OPS.A.005","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"aerodrome RFF category","definition":"A number from 1 to 10 that states the level of fire protection normally available, based on the longest aeroplanes' length and fuselage width.","source":"AMC2 ADR.OPS.B.010(a)(2)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"aerodrome traffic","definition":"Traffic on the manoeuvring area plus aircraft flying near the aerodrome, including those joining or leaving the circuit.","source":"SERA Art. 2(9)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"aerodrome traffic circuit","definition":"The specified path for aircraft that operate in the vicinity of an aerodrome.","source":"SERA Article 2(10)","page":null},{"term":"aerodrome traffic zone (ATZ)","definition":"Airspace of defined dimensions around an aerodrome for the protection of aerodrome traffic.","source":"SERA Article 2(11)","page":null},{"term":"Aeronautical beacon","definition":"Ground light visible at all azimuths, continuously or intermittently, designating a point on the earth's surface","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"aeronautical data","definition":"Formalised representation of aeronautical facts, concepts or instructions for communication, interpretation or processing.","source":"Reg. (EU) 2017/373 Annex I (9)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"aeronautical fixed service (AFS)","definition":"The telecommunication service between fixed points, mainly for the safety of air navigation, used to distribute NOTAM.","source":"Reg. (EU) 2017/373 Annex I (11)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"Aeronautical ground light","definition":"Any light specially provided as an aid to air navigation, other than one on an aircraft","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"aeronautical information","definition":"Information resulting from assembling, analysing and formatting aeronautical data.","source":"Reg. (EU) 2017/373 Annex I (13)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"aeronautical information product","definition":"Aeronautical data or information provided as digital data sets or a standardised paper or electronic presentation, such as the AIP, AIC, charts and NOTAM.","source":"Reg. (EU) 2017/373 Annex I (117)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"aeronautical information service (AIS)","definition":"The service that collects, processes, publishes and distributes aeronautical data and information for a State's territory.","source":"AIS.OR.105","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"aeroplane","definition":"A power-driven, heavier-than-air aircraft that gets its lift chiefly from surfaces that stay fixed in a given flight condition.","source":"SERA Article 2(16)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"AFIS","definition":"FIS for aerodrome traffic provided by a designated ATS provider.","source":"Reg. (EU) 2017/373 Annex I (6)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"AFIS / AFIS unit / AFIS aerodrome","definition":"FIS for aerodrome traffic; the unit giving AFIS and alerting service (suffix INFORMATION); an aerodrome where AFIS is provided","source":"","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"AFIS aerodrome","definition":"Aerodrome where AFIS is provided in its associated airspace.","source":"Reg. (EU) 2017/373 Annex I (125)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"AFIS unit","definition":"Unit providing AFIS and alerting service.","source":"Reg. (EU) 2017/373 Annex I (126)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"AIC","definition":"A notice with information that does not qualify for a NOTAM or for inclusion in the AIP, but relates to flight safety, air navigation, technical, administrative or legislative matters.","source":"Reg. (EU) 2017/373 Annex I (115)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"aiming point marking","definition":"Two conspicuous white stripes, one on each side of the runway centre line, marking the point where a pilot aims to touch down.","source":"CS ADR-DSN.L.540(a), (c)","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"AIP","definition":"The State publication of aeronautical information of a lasting character essential to air navigation.","source":"Reg. (EU) 2017/373 Annex I (118); SERA Art. 2(13)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"AIP amendment","definition":"A permanent change to the information in the AIP.","source":"Reg. (EU) 2017/373 Annex I (119)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"AIP supplement (SUP)","definition":"A temporary change to the AIP information, published on special pages.","source":"Reg. (EU) 2017/373 Annex I (120)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"Air Navigation Commission (ANC)","definition":"Body of aeronautical experts appointed by the Council; prepares and recommends changes to the Annexes.","source":"Arts 56, 57","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"air traffic","definition":"All aircraft in flight or on the manoeuvring area of an aerodrome.","source":"SERA Article 2(26)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"Air traffic advisory service","definition":"Service in advisory airspace that keeps IFR flights apart as far as practical; advice, not control","source":"SERA Article 2(27)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"air traffic control (ATC)","definition":"The ATC service, which keeps controlled flights apart from each other and keeps aerodrome traffic orderly.","source":"ATS.TR.105(a)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"air traffic control (ATC) service","definition":"A service that prevents collisions between aircraft (and with obstructions on the manoeuvring area) and keeps traffic flowing in order.","source":"SERA Article 2(30)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"air traffic services (ATS)","definition":"The services that prevent collisions, keep traffic orderly, give advice and information, and alert the right organisations about aircraft needing assistance.","source":"SERA.7001; ATS.TR.100","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"Air Transport Committee","definition":"Council committee for air transport (economic) matters, chosen from Council representatives.","source":"Art. 54(d)","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"air-to-ground signal","definition":"A manoeuvre or light signal made by an aircraft to show that a ground signal has been understood.","source":"Annex 12, Appendix 3","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"AIRAC","definition":"A system of advance notification, based on common effective dates, of circumstances that need significant changes in operating practices.","source":"Reg. (EU) 2017/373 Annex I (121)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"aircraft","definition":"Any machine that can be supported in the atmosphere by reactions of the air, other than reactions of the air against the earth's surface.","source":"SERA Article 2(18)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"Aircraft address","definition":"Unique 24-bit code per aircraft.","source":"SERA Art. 2(19)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Aircraft identification","definition":"Letters/figures equal to the call sign, sent by Mode S/ADS-B.","source":"SERA Art. 2(19a); SERA.13015","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Aircraft maintenance programme (AMP)","definition":"The document that organises an aircraft's maintenance; declared by the owner or approved by the CAMO/CAO.","source":"ML.A.302","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"aircraft security check","definition":"An inspection of the passenger-accessible interior and the hold for prohibited articles.","source":"Reg. (EC) No 300/2008 Art. 3(29)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"aircraft security search","definition":"An inspection of the interior and the accessible exterior of an aircraft.","source":"Reg. (EC) No 300/2008 Art. 3(30)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"Aircraft stand taxilane","definition":"Apron portion designated as a taxiway giving access to stands only","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"airside","definition":"The movement area of an airport, adjacent terrain and buildings, access to which is restricted.","source":"Reg. (EC) No 300/2008 Art. 3(11)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"Airway","definition":"Control area, or part of one, shaped as a corridor","source":"SERA Article 2(36)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"Airworthiness directive (AD)","definition":"Mandatory action issued or adopted by EASA to restore safety when an unsafe condition is likely to exist in other aircraft of the type.","source":"21.A.3B(a)–(b)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"Airworthiness review","definition":"Documented review of an aircraft's records plus a physical survey, done periodically to keep the airworthiness certificate valid.","source":"ML.A.901(a); ML.A.903(a)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"airworthiness review certificate (ARC)","definition":"Certificate (EASA Form 15c) issued after a satisfactory airworthiness review; valid 1 year, extendable twice.","source":"ML.A.901(b); ML.A.902(a)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"Airworthy","definition":"Conforming to an approved design and in a condition for safe operation.","source":"21.B.326(b)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"alert phase (ALERFA)","definition":"Apprehension exists about the safety of an aircraft and its occupants.","source":"Reg. (EU) 2017/373 Annex I (135); ATS.TR.405(b)(1)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"Alerting post","definition":"Facility acting as intermediary between a person reporting an emergency and an RCC/RSC.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"alerting service","definition":"Service notifying organisations about aircraft needing SAR aid and assisting them.","source":"SERA Article 2(37)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"altitude","definition":"The vertical distance of a level from mean sea level (MSL).","source":"SERA Article 2(39)","page":null},{"term":"AMC (acceptable means of compliance)","definition":"EASA material, adopted by Executive Director decision, showing an accepted way to meet an implementing rule.","source":"SERA EAR, Note from the editor","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"Annex","definition":"A set of SARPs adopted by the ICAO Council, designated an Annex to the Convention for convenience.","source":"Art. 54(l), Art. 90","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"anti-collision light","definition":"A light intended to attract attention to the aircraft.","source":"SERA.3215(a)(1)","page":null},{"term":"Approach control service / unit","definition":"ATC for arriving or departing controlled flights / the unit giving it (suffix APPROACH)","source":"SERA Article 2(40), (41)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"appropriate authority","definition":"The single national authority that coordinates and monitors the implementation of aviation security.","source":"Reg. (EC) No 300/2008 Art. 9","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"apron","definition":"A defined area for loading and unloading, fuelling, parking or maintenance of aircraft.","source":"SERA Article 2(42)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"apron boundary","definition":"The published limit of the apron, shown on the aerodrome chart.","source":"ADR.OPS.D.005; AMC1 ADR.OPS.D.005","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"apron management service (AMS)","definition":"The service that manages aircraft and vehicle activities and movements on an apron.","source":"Reg. (EU) No 139/2014 Art. 2(5)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"Area control centre (ACC) / area control service","definition":"Unit giving ATC to controlled flights in its control areas (suffix CONTROL) / the service itself","source":"SERA Article 2(43), (44)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"ARFF","definition":"Aircraft rescue and fire-fighting (aerodrome fire and rescue service).","source":"","page":{"id":"010-05-04","title":"Signals","url":"/010-air-law/05-rules-of-the-air/04-signals/"}},{"term":"arrival report","definition":"A report made after landing to close a flight plan.","source":"SERA.4020","page":{"id":"010-05-02","title":"Rules of the air: general rules","url":"/010-air-law/05-rules-of-the-air/02-rules-of-the-air-general-rules/"}},{"term":"ASDA","definition":"TORA plus the stopway, if provided.","source":"Reg. (EU) No 139/2014 Annex I (2)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"ASHTAM","definition":"A special-series NOTAM, in a specific format, on volcanic activity or an ash cloud.","source":"Reg. (EU) 2017/373 Annex I (29)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"Assembly","definition":"ICAO's body of all contracting States, one vote each; meets at least every three years; elects the Council.","source":"Arts 48, 49","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"ATC / FIS columns","definition":"The \"Applicable to\" columns showing whether a phrase is for an ATC function, an FIS function, or both.","source":"GM2 Appendix 1 to AMC1 SERA.14001","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"ATC clearance","definition":"Authorisation for an aircraft to proceed under conditions that an ATC unit specifies.","source":"SERA Article 2(28)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"ATC instruction","definition":"A directive from ATC that requires the pilot to take a specific action.","source":"SERA Article 2(29)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"ATIS / Voice-ATIS / D-ATIS","definition":"Automatic provision of current routine information to arriving and departing aircraft, by continuous voice broadcast (Voice-ATIS) or by data link (D-ATIS).","source":"SERA Article 2(49)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"ATS airspaces","definition":"Letter-designated airspaces with specified flight types, services and rules","source":"SERA Article 2(33)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"ATS reporting office (ARO)","definition":"Unit receiving ATS reports and pre-departure flight plans","source":"SERA Article 2(34)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"ATS route","definition":"Specified route that channels traffic for ATS (airways, advisory routes, VFR routes, etc.)","source":"SERA Article 2(46); GM1 Article 2(46)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"ATS surveillance service","definition":"Air traffic service given directly by means of an ATS surveillance system","source":"SERA Article 2(34a)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"ATS surveillance system","definition":"Umbrella term for ADS-B, PSR, SSR or comparable ground-based systems that allow aircraft identification","source":"Reg. (EU) 2017/373 Annex I (141)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"ATS unit","definition":"ATC unit, FIC, AFIS unit or ATS reporting office.","source":"SERA Article 2(35)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"autonomous aircraft detection system","definition":"A system that turns obstacle lights on only when an aircraft approaches.","source":"GM1 ADR-DSN.Q.840(d)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"aviation security","definition":"Measures plus human and material resources that safeguard civil aviation against acts of unlawful interference.","source":"Reg. (EC) No 300/2008 Art. 3(2)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"background check","definition":"A recorded check of a person's identity, including any criminal history, used for unescorted access to SRAs.","source":"Reg. (EC) No 300/2008 Art. 3(15)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"},"anchor":"letter-B"},{"term":"Barrette","definition":"Three or more closely spaced ground lights in a transverse line, appearing as a short bar","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"blind transmission","definition":"Transmission sent without contact or acknowledgement, prefixed \"TRANSMITTING BLIND\", and sent twice.","source":"SERA.14085(a)","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"Cabotage","definition":"Carriage for payment between points within one State's territory.","source":"Art. 7","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"},"anchor":"letter-C"},{"term":"CAMO / CAO","definition":"Approved organisations that can manage an aircraft's continuing airworthiness (CAO can also maintain).","source":"ML.A.201(e)–(f)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"catenary","definition":"The sagging curve of a wire between two towers. Its lowest point carries one high-intensity Type B light level.","source":"CS ADR-DSN.Q.852(d)(2)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"causes","definition":"Actions, omissions, events or conditions that led to an event. Identifying causes does not mean assigning fault.","source":"Reg. (EU) No 996/2010 Art. 2(4)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"CAVOK","definition":"Ceiling and visibility OK, spoken \"CAV-O-KAY\"","source":"Appendix 1 to AMC1 SERA.14001, 1.1.8 j","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"ceiling","definition":"The height above the ground or water of the base of the lowest cloud layer below 20 000 ft (6 000 m) that covers more than half of the sky.","source":"SERA Article 2(50)","page":null},{"term":"certificate of airworthiness (CofA)","definition":"Certificate (EASA Form 25) issued by the State of registry to an aircraft conforming to a type certificate; unlimited duration, valid only with a current ARC.","source":"21.A.173(a); 21.B.325(a); 21.A.181","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"certificate of deregistration","definition":"Document confirming removal from a register and cancellation of the certificate of registration.","source":"Annex 7 9","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"certificate of registration","definition":"Document issued by the State of Registry, following the Annex 7 model, showing marks, aircraft and registered holder.","source":"Annex 7 8","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"Certificate of release to service (CRS)","definition":"Statement issued after maintenance that the work was properly done; by certifying staff or, within limits, the pilot-owner.","source":"ML.A.801","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"certification specification (CS)","definition":"EASA design standard against which an aerodrome is certified; worded \"should\".","source":"CS ADR-DSN.A.001","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"checklist NOTAM","definition":"A periodic NOTAM that lists the valid NOTAM of a series, together with the latest AIP amendments, supplements and AIC.","source":"AIS.TR.330(s)-(v)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"Chicago Convention","definition":"The Convention on International Civil Aviation, signed at Chicago on 7 December 1944 and in force from 4 April 1947.","source":"Doc 7300 Foreword, preamble note 1","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"civil aviation","definition":"Air operations by civil aircraft, excluding State aircraft.","source":"Reg. (EC) No 300/2008 Art. 3(1)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"Class 2 medical certificate","definition":"The minimum medical certificate for PPL privileges.","source":"MED.A.030(c)(2)","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"Class rating","definition":"Rating for a class of single-pilot aeroplanes that does not need a type rating, for example SEP(land).","source":"FCL.010; FCL.705","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"clear of cloud","definition":"Out of cloud, with no specified distance from cloud. Used in Class F and G in the low band and for special VFR.","source":"SERA.5001, Table S5-1; SERA.5010(b)(1)","page":null},{"term":"Clearance limit","definition":"The point to which a clearance is granted","source":"SERA Article 2(52)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"clearway","definition":"Defined rectangular area on the ground or water, under aerodrome control, over which an aeroplane may make part of its initial climb.","source":"Reg. (EU) No 139/2014 Annex I (15); CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"closed marking","definition":"A marking, white on a runway and yellow on a taxiway, that shows a runway or taxiway, or part of one, is closed.","source":"CS ADR-DSN.R.855; ADR.OPS.B.071","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"Code (SSR) / squawk","definition":"Four-digit Mode A/C reply code; \"squawk\" = select a code (phraseology).","source":"SERA Art. 2(54); Appendix 1 to AMC1 SERA.14001, 2.3","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"code 7601","definition":"EU-only Mode A code for an IFR flight with radio failure that continues in VMC.","source":"SERA.14083(c)(6)","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"code pennant","definition":"A tapered flag with vertical red and white stripes; hoisted close up (fully raised) by a surface craft it means \"understood\".","source":"Annex 12, Appendix 1.2, Note","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"Colour safe","definition":"Able to readily distinguish the colours used in air navigation and identify aviation coloured lights.","source":"MED.A.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"common basic standards","definition":"The EU-wide baseline security standards set out in Annex I to the regulation.","source":"Reg. (EC) No 300/2008 Art. 4(1), Annex I","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"common mark","definition":"Mark assigned by ICAO to a common mark registering authority for aircraft of an international operating agency registered on a non-national basis.","source":"Annex 7 Ch. 1","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"common mark registering authority","definition":"Authority keeping the non-national register for an international operating agency's aircraft.","source":"Annex 7 Ch. 1","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"Compacted snow","definition":"Snow pressed into a solid mass that tyres run on without further rutting.","source":"Reg. 139/2014 Annex I (38h)(a)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"competent authority","definition":"The authority a Member State designates to exercise the options SERA gives it.","source":"SERA (several points)","page":null},{"term":"Complex motor-powered aircraft","definition":"For aeroplanes: above 5 700 kg MCTOM, or more than 19 passenger seats, or two-pilot minimum crew, or turbojet / more than one turboprop.","source":"Reg. (EU) No 748/2012 Art. 1(2)(ha)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"Conditional clearance","definition":"A clearance that applies only after a stated condition is met (e.g. after a landing aircraft passes)","source":"SERA.8015(ec)","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"conspicuity code","definition":"Code 7000, selected when not receiving air traffic services to improve detection by suitably equipped aircraft.","source":"SERA.13005(b)(3)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Contaminated runway","definition":"Runway covered in significant part by one of the surface condition descriptors.","source":"Reg. 139/2014 Annex I (15a)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"Contingency plan","definition":"A service provider's plan for significant degradation or interruption of its services.","source":"ATS.OR.135","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"continuing airworthiness","definition":"All processes keeping an aircraft compliant with airworthiness requirements and safe to operate throughout its life.","source":"Reg. (EU) No 1321/2014 Art. 2(d)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"Contracting State","definition":"A State party to the Convention.","source":"Doc 7300 (passim)","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"contributing factors","definition":"Factors whose removal would have made the event less likely or less severe. They imply no fault.","source":"Annex 13 Ch. 1","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"control area","definition":"Controlled airspace that starts at a specified limit above the earth.","source":"SERA Article 2(56)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"control zone (CTR)","definition":"Controlled airspace from the surface up to a specified upper limit.","source":"SERA Article 2(61)","page":null},{"term":"controlled aerodrome","definition":"Aerodrome where ATC is provided to aerodrome traffic.","source":"SERA Art. 2(57)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"controlled airspace","definition":"Airspace where ATC service is provided according to its class (Classes A–E).","source":"SERA Article 2(58); GM1 Article 2(58)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"controlled flight","definition":"Any flight that is subject to an ATC clearance.","source":"SERA Article 2(59)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"Cospas-Sarsat","definition":"International satellite system that detects 406 MHz distress beacons and passes alerts to RCCs via its Mission Control Centres and the SAR point of contact.","source":"Annex 12, 2.4.1(j), 3.2.5, 5.2.4(b)","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"Council","definition":"Permanent ICAO body of elected States, responsible to the Assembly; adopts standards and recommended practices as Annexes.","source":"Arts 50, 54","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"Critical area / sensitive area","definition":"Areas around precision approach ground equipment where aircraft or vehicles would disturb the guidance signal.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"critical parts of SRA","definition":"Parts of an SRA where all non-passengers are screened on entry.","source":"Reg. (EC) No 300/2008 Annex I points 1.1.2(d), 1.3.2","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"cruising level","definition":"A level that an aircraft holds for a significant part of a flight.","source":"SERA Article 2(63)","page":null},{"term":"Current / filed flight plan","definition":"Flight plan including later clearance changes / as originally filed","source":"SERA Article 2(64), (73)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"Customs airport","definition":"Airport designated by a State for customs and other examination of arriving and departing aircraft.","source":"Art. 10","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"danger area","definition":"Airspace in which activities dangerous to flight may exist at specified times.","source":"SERA Article 2(65)","page":{"id":"010-05-02","title":"Rules of the air: general rules","url":"/010-air-law/05-rules-of-the-air/02-rules-of-the-air-general-rules/"},"anchor":"letter-D"},{"term":"declared distances","definition":"TORA, TODA, ASDA and LDA published for each runway direction.","source":"Reg. (EU) No 139/2014 Annex I (18); GM1 ADR.OPS.A.005","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"demarcated area","definition":"An area separated by access control from the SRAs, or from the other SRAs when it is itself an SRA.","source":"Reg. (EC) No 300/2008 Art. 3(14)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"Difference (from a Standard)","definition":"A way in which a State's rules or practices depart from an international standard; must be notified to ICAO.","source":"Art. 38","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"direction sign","definition":"Black-on-yellow sign naming a taxiway with an arrow showing its direction at an intersection.","source":"CS ADR-DSN.N.785(a)(8), (c)(7)","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"Discrete code","definition":"Four-digit SSR code whose last two digits are not 00","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"displaced threshold","definition":"Threshold not located at the physical end of the runway.","source":"CS ADR-DSN.A.002; Annex 14 Ch. 1","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"distance from cloud","definition":"The horizontal and vertical distance between the aircraft and cloud that VMC requires (1 500 m horizontally and 1 000 ft vertically in most bands of Table S5-1).","source":"SERA.5001, Table S5-1","page":null},{"term":"distress","definition":"A state of grave and imminent danger that needs immediate assistance. Signals include MAYDAY, SOS, red lights and transponder code 7700.","source":"SERA App. 1, 1.2.1","page":null},{"term":"distress beacon","definition":"Generic term for a transmitter that signals distress; Annex 12 does not define it.","source":"Annex 12, 5.6.2(c), 5.7.2","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"distress phase (DETRESFA)","definition":"Reasonable certainty of grave and imminent danger, or need for immediate assistance.","source":"Reg. (EU) 2017/373 Annex I (174); ATS.TR.405(b)(1)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"distress scene","definition":"Term used from 26 November 2026 for the place of a distress in the Annex 12 PIC procedures.","source":"Annex 12, 5.6 footnote 2","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"Ditching","definition":"Forced landing of an aircraft on water.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"Downstream clearance","definition":"Clearance from an ATC unit not yet controlling the aircraft","source":"SERA Article 2(68)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"Dry runway","definition":"Runway free of visible moisture and not contaminated.","source":"Reg. 139/2014 Annex I (18a)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"dual obstacle lighting system","definition":"A system that shows white lights by day and twilight, and red medium-intensity lights at night, near an aerodrome.","source":"GM1 ADR-DSN.Q.846(c)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"dumb-bell","definition":"A white ground signal shaped like a dumb-bell. Alone, it means use runways and taxiways only. With black bars, it means runways only for take-off and landing.","source":"SERA App. 1, 3.2.3","page":null},{"term":"eAIP","definition":"Electronic form of the AIP, displayable on screen and printable.","source":"AIS.TR.305(a)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"},"anchor":"letter-E"},{"term":"ELA1 / ELA2 aeroplane","definition":"Non-complex aeroplane of 1 200 kg / 2 000 kg MTOM or less.","source":"Reg. (EU) No 748/2012 Art. 1(2)(i), (j)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"ELT (emergency locator transmitter)","definition":"Distress beacon carried by an aircraft; Annex 12 does not define it and refers to Annex 6 (carriage) and Annex 10 Vol III (specifications); frequencies 121.5 MHz and 406.0–406.1 MHz.","source":"Annex 12, 2.6.4 Notes","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"emergency access road","definition":"A road that lets RFFS vehicles reach parts of the aerodrome and its approach areas quickly.","source":"GM1 ADR-DSN.T.900","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"emergency authority","definition":"The pilot-in-command's right to act at once against the flight plan or clearance in an emergency, then tell ATS.","source":"SERA.8020(a); SERA.2010(a)","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"emergency frequency 121.5 MHz","definition":"The VHF emergency frequency, to be used only for emergency purposes.","source":"SERA Article 4a; SERA.11015(b)(3)","page":null},{"term":"emergency phase","definition":"Uncertainty, alert or distress phase.","source":"GM1 Annex IV (Part-ATS) to Reg. (EU) 2017/373","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"emergency separation","definition":"Temporary vertical separation of half the normal minimum, used in an emergency when horizontal separation cannot be kept.","source":"AMC1 ATS.TR.210(c)","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"Endorsement (Art. 39)","definition":"A list, on or attached to a certificate of airworthiness or licence, of the respects in which it does not meet the international standard.","source":"Art. 39","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"Enhanced taxiway centre line","definition":"Continuous yellow centre line flanked by yellow dashed lines before a runway-holding position, warning of a nearby runway","source":"CS ADR-DSN.L.570","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"Essential local traffic","definition":"Aircraft, vehicle or person on/near the manoeuvring area, or traffic in the climb-out or final approach area, that may be a hazard","source":"Reg. (EU) 2017/373 Annex I (177)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"extensive object","definition":"An object, or a group of objects such as a group of buildings or a wind farm, whose extent needs outlining with several lights.","source":"GM1 ADR-DSN.Q.847; CS ADR-DSN.Q.851(c)(2)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"fatal injury","definition":"Injury suffered in an accident that results in death within 30 days of the accident.","source":"Reg. (EU) No 996/2010 Art. 2(5)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"},"anchor":"letter-F"},{"term":"fireproof material","definition":"Material that withstands heat at least as well as steel, with dimensions suited to the purpose.","source":"Annex 7 Ch. 1","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"Fixed light","definition":"Light of constant intensity seen from a fixed point","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"Fixed message sign","definition":"A sign showing only one message.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"flight information centre (FIC)","definition":"Unit that provides FIS and alerting service.","source":"SERA Article 2(75)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"flight information region (FIR)","definition":"Defined airspace in which FIS and alerting service are provided.","source":"SERA Article 2(76)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"flight information service (FIS)","definition":"Service giving advice and information for safe and efficient flight.","source":"SERA Article 2(77)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"Flight information zone (FIZ)","definition":"Airspace where AFIS and alerting service for aerodrome traffic are provided","source":"","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"flight level (FL)","definition":"A surface of constant atmospheric pressure related to the pressure datum 1013.2 hPa, separated from other such surfaces by set pressure intervals.","source":"SERA Article 2(78)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"Flight path monitoring","definition":"Use of surveillance to advise aircraft of significant deviations from their nominal path or clearance","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"flight plan","definition":"Information given to ATS units about an intended flight or part of a flight.","source":"SERA Article 2(79)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"flight recorder","definition":"Recorder installed in an aircraft to help investigations.","source":"Reg. (EU) No 996/2010 Art. 2(6)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"Flight time","definition":"From the aircraft first moving to take off until it finally comes to rest after the flight.","source":"FCL.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"flight visibility","definition":"The visibility forward from the cockpit of an aircraft in flight.","source":"SERA Article 2(80)","page":null},{"term":"FOD (foreign object debris)","definition":"Loose objects on the movement area that can damage aircraft or be blown about.","source":"ADR.OPS.D.035(f); ADR.OPS.D.040(c)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"FOLLOW-ME vehicle","definition":"A vehicle that leads an aircraft along its apron route.","source":"AMC1 ADR.OPS.D.015(a); ADR.OPS.D.080","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"frangible object","definition":"Low-mass object designed to break, distort or yield on impact, which reduces the hazard to aircraft.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"general call","definition":"Unacknowledged transmission to all aircraft concerned.","source":"AMC1 ATS.TR.305(a)(1)(ii)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"},"anchor":"letter-G"},{"term":"geometric height (GNSS)","definition":"A height derived from satellite navigation, not from air pressure.","source":"ATS.TR.155(f); AMC2 ATS.TR.155(f)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"GM (guidance material)","definition":"EASA explanatory material that helps interpret a rule or AMC","source":"SERA EAR, Note from the editor","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"Graded area","definition":"Part of the strip cleared and graded to limit damage to an aircraft running off the runway.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"ground visibility","definition":"The visibility at an aerodrome, reported by an accredited observer or by an automatic system.","source":"SERA Article 2(82)","page":null},{"term":"ground-air visual signal code","definition":"A set of large symbols laid out on the ground to pass messages to aircraft, one set for survivors and one for rescue units.","source":"Annex 12, Appendix 2","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"handover point","definition":"A designated point where responsibility for an aircraft passes between apron management and ATS.","source":"ADR.OPS.D.010(a)(1)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"},"anchor":"letter-H"},{"term":"hazard","definition":"Situation or object with the potential to cause injury, damage, loss or reduced ability to perform a function.","source":"Reg. (EU) No 376/2014 Art. 2(10)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"heading","definition":"The direction of the aircraft's longitudinal axis, in degrees from true, magnetic, compass or grid north.","source":"SERA Article 2(83)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"heavier-than-air aircraft","definition":"Aircraft deriving lift in flight chiefly from aerodynamic forces.","source":"Annex 7 Ch. 1","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"height","definition":"The vertical distance of a level from a specified datum.","source":"SERA Article 2(84)","page":null},{"term":"hot spot","definition":"Location with a history or risk of collision or runway incursion that needs extra attention.","source":"Reg. (EU) No 139/2014 Annex I (19b)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"IAMSAR Manual","definition":"International Aeronautical and Maritime Search and Rescue Manual (ICAO/IMO Doc 9731); Volume III covers mobile facilities and also lists these signals.","source":"Annex 12, 5.6.5, Note","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"},"anchor":"letter-I"},{"term":"ICAO","definition":"International Civil Aviation Organization, created by the Chicago Convention; a United Nations agency with 193 Contracting States.","source":"Chicago Convention, Art. 43","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"IDENT","definition":"Transponder feature that highlights the aircraft on the controller's display; used only on request.","source":"SERA.13001(b); Appendix 1, 2.3.7","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Identification","definition":"An aircraft's position indication is seen on the display and positively identified","source":"Reg. (EU) 2017/373 Annex I (200)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"identification beacon","definition":"Aeronautical beacon emitting a coded signal identifying a point of reference.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"identification plate","definition":"Fireproof plate showing at least the nationality/common and registration marks, fixed near the main entrance.","source":"Annex 7 10.1-10.2","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"immediate take-off","definition":"Clearance to enter the runway and take off without stopping.","source":"GM1 SERA.8005(a)(3)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"incident","definition":"Occurrence other than an accident that affects, or could affect, the safety of operation.","source":"Reg. (EU) No 996/2010 Art. 2(7)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"Information marking","definition":"Yellow-on-black (location) or black-on-yellow (direction/destination) surface inscription","source":"CS ADR-DSN.L.610","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"information sign","definition":"Sign identifying a location or giving routing information; black on yellow, except location signs (yellow on black).","source":"CS ADR-DSN.N.785","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"Instrument / non-instrument runway","definition":"Runway intended for instrument approach procedures / for visual approach procedures.","source":"Reg. 139/2014 Annex I (22), (34)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"instrument meteorological conditions (IMC)","definition":"Weather conditions, described by visibility, distance from cloud and ceiling, worse than the VMC minima.","source":"SERA Article 2(91)","page":null},{"term":"intercept control unit","definition":"The ground unit directing the interceptor, with which the intercepted aircraft may talk on 121.5 MHz.","source":"","page":{"id":"010-05-05","title":"Interception of civil aircraft","url":"/010-air-law/05-rules-of-the-air/05-interception-of-civil-aircraft/"}},{"term":"intercepted aircraft","definition":"The civil aircraft being intercepted, which must follow the interceptor's instructions.","source":"SERA.11015(b)","page":null},{"term":"intercepting aircraft (interceptor)","definition":"The aircraft that carries out an interception and gives the signals.","source":"SERA.11015, Tables S11-1, S11-2","page":null},{"term":"interception","definition":"The approach of a normally military aircraft to a civil aircraft, to identify it and, if needed, guide it or make it land. Interception is a last resort.","source":"SERA.11015(a); AMC1 SERA.11015(a); GM1 SERA.11015, 1.1","page":null},{"term":"Intermediate holding position","definition":"Designated position for traffic control where taxiing aircraft and vehicles stop and hold until cleared, when ATC so instructs","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"International flag \"N\"","definition":"A blue and white chequered square flag; from a ship in reply to the \"follow me\" signal it means \"unable to comply\".","source":"Annex 12, Appendix 1.2, Note","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"international flag N","definition":"A blue and white chequered square flag; from a surface craft in reply to the \"follow me\" signal it means \"unable to comply\".","source":"Annex 12, Appendix 1.2, Note","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"international NOTAM office (NOF)","definition":"The office a State designates to exchange NOTAM internationally.","source":"Reg. (EU) 2017/373 Annex I (197)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"international operating agency","definition":"Agency of the kind allowed by Chicago Convention Art. 77 (jointly set up by two or more States).","source":"Annex 7 Ch. 1","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"investigator-in-charge","definition":"Qualified person responsible for organising, conducting and controlling a safety investigation.","source":"Reg. (EU) No 996/2010 Art. 2(9)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"jet blast / propeller slipstream","definition":"The high-speed air behind an engine or propeller that is on, which can blow over people, equipment and light aircraft.","source":"ADR.OPS.D.055","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"},"anchor":"letter-J"},{"term":"Joint rescue coordination centre (JRCC)","definition":"RCC for both aeronautical and maritime SAR.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"just culture","definition":"Approach in which front-line operators are not punished for actions that match their experience and training, while gross negligence, wilful violations and destructive acts are not tolerated.","source":"Reg. (EU) No 376/2014 Art. 2(12)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"Landing area","definition":"Part of the movement area intended for landing or take-off.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"},"anchor":"letter-L"},{"term":"landing T","definition":"A white or orange T-shaped ground signal that shows the landing and take-off direction, towards the cross arm.","source":"SERA App. 1, 3.2.5.1","page":null},{"term":"landside","definition":"The parts of an airport, adjacent terrain and buildings that are not airside.","source":"Reg. (EC) No 300/2008 Art. 3(12)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"Language proficiency endorsement","definition":"Licence entry that shows the language, the level and the validity date. The minimum level is Level 4.","source":"FCL.055","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"LDA","definition":"Runway length declared available and suitable for the ground run of an aeroplane landing.","source":"Reg. (EU) No 139/2014 Annex I (24)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"level","definition":"A generic term for a height, an altitude or a flight level.","source":"SERA Article 2(93)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"level of protection","definition":"The firefighting capability (agents, rates, vehicles, people) actually provided, stated as an RFF category.","source":"AMC2 ADR.OPS.B.010(a)(2); GM1 ADR.OPS.A.005","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"light signal","definition":"A coloured, steady or flashing light directed from aerodrome control to an aircraft, vehicle or person, with a meaning set by the rules of the air signals.","source":"SERA App. 1, 3.1","page":null},{"term":"lighter-than-air aircraft","definition":"Aircraft supported chiefly by buoyancy.","source":"Annex 7 Ch. 1","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"Limitation (medical)","definition":"A condition on the medical certificate that must be complied with while flying.","source":"MED.A.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"location indicator","definition":"The four-letter ICAO code for an aerodrome or FIR, from ICAO Doc 7910, used in NOTAM Item A.","source":"AIS.TR.330(n)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"location sign","definition":"Yellow-on-black sign naming the taxiway, runway or pavement the aircraft is on or entering; no arrows.","source":"CS ADR-DSN.N.785(c)(2), (c)(8)","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"long final","definition":"The report made when turning onto final more than 7 km (4 NM) from touchdown, or at 15 km (8 NM) from touchdown on a straight-in approach.","source":"Appendix 1 to AMC1 SERA.14001, 1.4.15 Note","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"low-/medium-/high-intensity obstacle light","definition":"Three families of obstacle light of increasing brightness. Each light type has a letter that shows its colour and whether it is fixed or flashing.","source":"CS ADR-DSN.Q.846(b); Table Q-1","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"lowest usable flight level","definition":"The lowest flight level that can be used where no transition altitude is established (term used, not defined, in SERA).","source":"SERA.3110","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"magnetic track","definition":"The track that selects the VFR cruising level in SERA Appendix 3 (grid track in polar areas above 70° latitude, where prescribed).","source":"SERA Appendix 3, footnote 1","page":null,"anchor":"letter-M"},{"term":"maintenance","definition":"Overhaul, repair, inspection, replacement, modification or defect rectification; not the pre-flight inspection.","source":"Reg. (EU) No 1321/2014 Art. 2(h)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"Mandatory instruction marking","definition":"White-on-red surface inscription replacing or supplementing a mandatory instruction sign","source":"CS ADR-DSN.L.605","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"mandatory instruction sign","definition":"White-on-red sign marking a place a taxiing aircraft or vehicle must not pass without tower authorisation.","source":"CS ADR-DSN.N.780(a)(1), (c)(1)","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"manoeuvring area","definition":"Take-off, landing and taxiing areas, excluding aprons.","source":"SERA Art. 2(94)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"marker","definition":"Object displayed above ground level to indicate an obstacle or delineate a boundary.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"marking","definition":"Symbol or group of symbols on the surface of the movement area that conveys aeronautical information.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"MAYDAY / PAN PAN","definition":"Radiotelephony signals that open the first message of a distress (MAYDAY) or urgency (PAN PAN) communication.","source":"SERA.14095(a)(2)","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"Minimum fuel (minimum fuel/energy)","definition":"Report that the flight is committed to one aerodrome and further delay could eat into final reserve; not an emergency.","source":"GM1 SERA.11012","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"Mode A / Mode C / Mode S","definition":"A: identity code; C: code + pressure-altitude; S: selective, with 24-bit address and aircraft identification.","source":"SERA Appendix 6 Item 10; Art. 2(19) (detail 060-08-02)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Mode C level verification","definition":"The check by ATS that the level displayed by the transponder is within the approved tolerance of the reported level.","source":"SERA.13010(b)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"mountainous area","definition":"An area where terrain elevation changes by more than 900 m (3 000 ft) within 18.5 km (10.0 NM).","source":"SERA Article 2(95b)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"movement area","definition":"Manoeuvring area plus aprons.","source":"SERA Art. 2(96)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"MSAW","definition":"Minimum safe altitude warning: ground system warning of possible infringement of a minimum safe altitude","source":"GM3 ATS.TR.155(c)(9)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"Multilateration (MLAT)","definition":"Position derived from transponder signals received at several ground stations, mainly by time difference of arrival","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"national civil aviation security programme","definition":"The State document that sets out security responsibilities and measures.","source":"Reg. (EC) No 300/2008 Art. 10","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"},"anchor":"letter-N"},{"term":"nationality mark","definition":"Group of characters taken from the ITU radio call-sign series allocated to the State of Registry, placed first in the aircraft's marks.","source":"Annex 7 3.3","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"navigation lights","definition":"Lights intended to show an observer the relative path of the aircraft.","source":"SERA.3215(a)(2)","page":null},{"term":"night","definition":"The time from the end of evening civil twilight to the start of morning civil twilight. Civil twilight ends or starts when the centre of the sun is 6° below the horizon.","source":"SERA Article 2(97)","page":null},{"term":"Night rating","definition":"Rating that allows LAPL or PPL privileges in VFR at night.","source":"FCL.810","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"No-entry bar","definition":"Row of red lights across an exit-only taxiway preventing wrong-way entry","source":"CS ADR-DSN.M.771","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"Noise certificate","definition":"Separate certificate (EASA Form 45) showing the noise standard the aircraft meets.","source":"21.B.425; Appendix VII","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"Non-instrument runway","definition":"Runway for aircraft using visual approach procedures","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"non-load-bearing surface","definition":"A paved-looking surface, such as a taxiway shoulder, that can damage an aircraft that uses it.","source":"CS ADR-DSN.R.860(a)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"Non-precision approach runway","definition":"Instrument runway with visual aids and at least one non-visual aid, for landings after a type A instrument approach","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"Non-scheduled flight","definition":"A flight not part of a scheduled international air service; has rights of entry, transit and non-traffic stops under Art. 5.","source":"Art. 5","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"normal code","definition":"A code selected as ATS instructs or, without instructions, the default code 2000 or the conspicuity code 7000.","source":"SERA.13005(b)(1)–(3)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"NOTAM","definition":"A notice distributed by telecommunication about the establishment, condition or change of a facility, service, procedure or hazard, the timely knowledge of which is essential to people involved in flight operations.","source":"Reg. (EU) 2017/373 Annex I (73); SERA Art. 2(97a)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"NOTAMN / NOTAMR / NOTAMC","definition":"New, replacing and cancelling NOTAM.","source":"Annex VI Appendix 2","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"obstacle","definition":"A fixed or mobile object, or part of one, on a surface where aircraft move, above a protective surface, or outside those surfaces but assessed as hazardous.","source":"Reg. (EU) No 139/2014 Art. 2(13)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"},"anchor":"letter-O"},{"term":"obstacle limitation surface (OLS)","definition":"A surface that defines how high objects may project into the airspace around an aerodrome.","source":"Reg. (EU) No 139/2014 Art. 2(14)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"obstacle protection surface","definition":"A surface that protects a visual approach slope indicator; new objects are not permitted above it unless shielded.","source":"Reg. (EU) No 139/2014 Art. 2(15)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"occurrence","definition":"Any safety-related event that endangers, or could endanger, an aircraft, its occupants or any other person. Includes accidents and serious incidents.","source":"Reg. (EU) No 376/2014 Art. 2(7)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"operating site","definition":"A site that the operator or pilot-in-command selects for landing, take-off and/or hoist operations.","source":"SERA Article 2(99)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"overtaking aircraft","definition":"An aircraft that approaches another aircraft from behind, on a line forming an angle of less than 70° with the other aircraft's plane of symmetry.","source":"SERA.3210(c)(3)","page":null},{"term":"PANS","definition":"Procedures for Air Navigation Services; ICAO documents alongside the Annexes (six exist).","source":"","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"},"anchor":"letter-P"},{"term":"PAPI / APAPI","definition":"Precision approach path indicator (four light units) / abbreviated PAPI (two light units).","source":"CS ADR-DSN.M.645","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"Part-FCL","definition":"Annex I to Reg. (EU) No 1178/2011: EU rules for pilot licences, ratings and certificates.","source":"Reg. (EU) No 1178/2011; FCL.005","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"Part-MED","definition":"Annex IV to Reg. (EU) No 1178/2011: EU rules for aircrew medical certificates.","source":"MED.A.005","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"PCN","definition":"Pavement classification number: the pavement-strength figure in the ACN-PCN report.","source":"GM1 ADR.OPS.A.005","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"PCR / ACR","definition":"ICAO pavement classification rating (pavement strength) / aircraft classification rating (aircraft's effect on a pavement); aircraft with ACR ≤ PCR may use the pavement.","source":"Annex 14 Ch. 1, 2.6.3","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"permit to fly","definition":"Authorisation (EASA Form 20a/20b) for an aircraft that does not meet or is not shown to meet airworthiness requirements to fly for set purposes under set conditions.","source":"21.A.701; 21.A.711","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"person involved","definition":"Owner, crew member or operator of an aircraft in an accident or serious incident, and others linked to its maintenance, design, training or air traffic services.","source":"Reg. (EU) No 996/2010 Art. 2(11)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"PIB","definition":"A plain-language summary of valid NOTAM of operational significance and other urgent information, prepared for flight crews before flight.","source":"GM1 AIS.OR.405(b)(c); ICAO Annex 15 Ch. 1","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"PIC","definition":"Pilot designated as being in command and responsible for the safe conduct of the flight.","source":"FCL.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"pilot-owner","definition":"Licensed pilot who owns (or co-owns) the aircraft and may release limited maintenance on a Part-NCO aircraft.","source":"ML.A.803","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"plain language","definition":"Ordinary language, used only when no standard phraseology can carry the intended message.","source":"SERA.14001; GM2 Appendix 1 to AMC1 SERA.14001","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"Position indication","definition":"Symbol or blip on the situation display showing an aircraft's position","source":"Reg. (EU) 2017/373 Annex I (215)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"PPL(A)","definition":"Private pilot licence for aeroplanes. The holder acts as PIC or co-pilot without remuneration in non-commercial operations.","source":"FCL.205.A","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"Pre-flight altimeter check location","definition":"Published-elevation area (often the apron) used to check the altimeter before flight.","source":"GM1 ADR.OPS.A.005","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"pre-flight inspection","definition":"Inspection before flight to make sure the aircraft is fit for the intended flight; the PIC's responsibility.","source":"Reg. (EU) No 1321/2014 Art. 2(j); ML.A.201(d)","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"pre-threshold area","definition":"A paved area before a threshold that is not suitable for normal aircraft use. It carries chevron marking when it is longer than 60 m.","source":"CS ADR-DSN.R.865","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"Precision approach runway (CAT I/II/III)","definition":"Instrument runway with visual aids and at least one non-visual aid, for landings after a type B CAT I/II/III approach","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"preliminary report","definition":"Early communication of data from an investigation.","source":"Reg. (EU) No 996/2010 Art. 2(12)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"pressure-altitude","definition":"A pressure expressed as its altitude in the Standard Atmosphere.","source":"SERA Article 2(101)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"Primary surveillance radar (PSR)","definition":"Radar that detects aircraft from reflected energy; shown as a \"PSR blip\"; needs no aircraft equipment","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"principal / complementary agent","definition":"Principal: foam (performance level A, B or C). Complementary: dry chemical powder or an equivalent, for fast knock-down of fuel fires.","source":"AMC4 ADR.OPS.B.010(a)(2)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"procedure word","definition":"The defined words and phrases with fixed meanings, such as ROGER, WILCO, AFFIRM and STANDBY.","source":"SERA.14045(b)","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"Procedure words","definition":"The defined words and phrases with fixed meanings, such as ROGER, WILCO, AFFIRM and STANDBY.","source":"SERA.14045(b)","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"Prohibited area","definition":"Area over which a State restricts or prohibits flight for military necessity or public safety.","source":"Art. 9","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"prohibited articles","definition":"Weapons, explosives or other dangerous devices, articles or substances that may be used to commit an act of unlawful interference.","source":"Reg. (EC) No 300/2008 Art. 3(7)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"projected course","definition":"The track a surface craft will follow if it holds its present heading; the aircraft crosses it close ahead for \"follow me\".","source":"Annex 12, Appendix 1.1(b) (usage)","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"Provisional ICAO (PICAO)","definition":"The interim organisation set up by the Interim Agreement signed at Chicago on 7 December 1944, before the Convention came into force.","source":"Art. 45","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"psychoactive substance","definition":"Alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens and volatile solvents (not caffeine or tobacco).","source":"SERA Article 2(104)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"pyrotechnic signal","definition":"A flare or rocket used as a signal, for example a red pyrotechnic meaning do not land for the time being.","source":"SERA App. 1, 1.2.1(d), (e); Table AP 1-1","page":null},{"term":"QFE","definition":"The altimeter setting that makes the altimeter read height above the aerodrome QFE datum.","source":"GM1 SERA Article 2(84)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"},"anchor":"letter-Q"},{"term":"QNH","definition":"The altimeter setting that makes the altimeter read altitude above mean sea level.","source":"GM1 SERA Article 2(39)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"Radar approach","definition":"Approach whose final phase is directed by a controller using radar","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"},"anchor":"letter-R"},{"term":"Radar clutter","definition":"Unwanted signals shown on a situation display","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"Radar contact","definition":"An aircraft's radar position is seen and identified on a situation display","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"radio communication failure procedure","definition":"Fixed actions after failed attempts to re-establish contact, including code 7600, and for a VFR flight staying in VMC, landing at the nearest suitable aerodrome and reporting arrival.","source":"SERA.14083","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"radio mandatory zone (RMZ)","definition":"Airspace where VFR flights in Class E, F or G keep a continuous listening watch and make an initial call before entry.","source":"SERA.6005(a)","page":null},{"term":"RCAM","definition":"Runway condition assessment matrix, used to assign the RWYCC.","source":"Reg. (EU) No 139/2014 Annex I (38a)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"RDRS","definition":"Runway distance remaining sign: optional ICAO white-on-black sign beside the runway showing distance to go.","source":"Annex 14 5.4.8","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"readback","definition":"Repetition by the pilot of an item, such as an SSR code, to confirm that it was received correctly.","source":"SERA.8015(e)(1)(iii)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"Reduced runway separation minima (RRSM)","definition":"Locally prescribed, daylight-only shorter runway spacing for light propeller types","source":"AMC9 ATS.TR.210(c)(2)(i)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"registration mark","definition":"Letters and/or numbers assigned by the State of Registry (or common mark registering authority), following the nationality or common mark.","source":"Annex 7 3.5","page":{"id":"010-03-01","title":"Nationality and registration marks","url":"/010-air-law/03-nationality-and-registration-marks/01-nationality-and-registration-marks/"}},{"term":"reporter","definition":"Natural person who reports an occurrence or safety information.","source":"Reg. (EU) No 376/2014 Art. 2(1)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"Reporting point / significant point","definition":"Location against which position is reported / location defining a route or flight path","source":"SERA Article 2(110), (121)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"RESA","definition":"Runway end safety area; a symmetrical area beyond the end of the strip, mainly to reduce damage to an aeroplane that undershoots or overruns the runway.","source":"Reg. (EU) No 139/2014 Annex I (38d); CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"Rescue","definition":"Operation to retrieve persons in distress, meet initial needs and deliver them to a place of safety.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"rescue and firefighting services (RFFS)","definition":"The aerodrome service that responds to aircraft accidents and incidents at or near the aerodrome to save lives.","source":"ADR.OPS.B.010; GM1 ADR.OPS.B.010(a)(1)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"rescue coordination centre (RCC)","definition":"Unit that organises SAR services and coordinates SAR operations in a SAR region.","source":"Reg. (EU) 2017/373 Annex I (82)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"Rescue subcentre (RSC)","definition":"Unit subordinate to an RCC, set up to complement it.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"rescue unit","definition":"A unit (ground team, vessel or aircraft) taking part in a rescue; here, the ground team laying out the rescue-unit symbols.","source":"Annex 12, Chapter 1","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"response time","definition":"Time from the initial call to the RFFS until the first vehicles can apply foam at at least 50 % of the required rate.","source":"AMC5 ADR.OPS.B.010(a)(2)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"restricted area","definition":"Airspace over a State's land or territorial waters in which flight is restricted by specified conditions.","source":"SERA Article 2(111)","page":{"id":"010-05-02","title":"Rules of the air: general rules","url":"/010-air-law/05-rules-of-the-air/02-rules-of-the-air-general-rules/"}},{"term":"restricted certificate of airworthiness","definition":"Certificate (EASA Form 24, or 24B for declared designs) for an aircraft conforming to a restricted TC or specific airworthiness specifications; carries limitations for use.","source":"21.A.173(b); 21.B.325(b); 21.B.327","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"RETILs","definition":"Rapid exit taxiway indicator lights: yellow 3-2-1 distance-to-go lights","source":"CS ADR-DSN.M.700","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"retroreflective","definition":"Reflecting light back towards its source, such as an aircraft's taxi light.","source":"","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"Revalidation / renewal","definition":"Revalidation extends a rating within its validity period. Renewal restores a rating after it lapses.","source":"FCL.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"right-of-way","definition":"The priority one aircraft has over another under the rules of the air. The aircraft with right-of-way keeps its heading and speed.","source":"SERA.3210(a)","page":null},{"term":"Road-holding position","definition":"Designated position where vehicles may be required to hold","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"runway condition report","definition":"Standardised report of runway surface condition and its effect on performance, using the RWYCC.","source":"Reg. (EU) No 139/2014 Annex I (38c)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"runway guard lights","definition":"Lights cautioning pilots and drivers that they are about to enter an active runway.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"runway incursion","definition":"Incorrect presence of an aircraft, vehicle or person on the protected area of a landing or take-off surface.","source":"GM1 Annex IV (Part-ATS)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"runway strip","definition":"Defined area that includes the runway and any stopway, reducing the risk of damage to aircraft that run off the runway and protecting aircraft flying over it.","source":"Reg. (EU) No 139/2014 Annex I (38f); CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"Runway turn pad","definition":"Defined area next to a runway for completing a 180° turn","source":"CS ADR-DSN.A.002","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"runway vacated sign","definition":"Black-on-yellow sign showing the pattern A holding-position marking; marks the edge of the protected area for an aircraft leaving the runway.","source":"CS ADR-DSN.N.785(a)(4), (c)(4)","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"runway-holding position","definition":"A designated point that protects a runway, where taxiing aircraft and vehicles stop and hold.","source":"SERA Article 2(114); GM1 Article 2(114)","page":null},{"term":"Runway-holding position / holding point","definition":"Designated place protecting a runway, OLS or ILS area where traffic stops unless the tower authorises","source":"SERA Art. 2(114); GM1 Annex IV (Part-ATS)","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"runway-holding position marking","definition":"Yellow marking painted along a runway-holding position, in pattern A or pattern B.","source":"CS ADR-DSN.L.575(a)","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"Runway-in-use","definition":"Runway selected by the tower for take-off and landing","source":"ATS.TR.260","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"RVR","definition":"Range over which a pilot on the runway centre line can see the runway markings or lights","source":"CS ADR-DSN.A.002","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"RWSL (RELs, THLs)","definition":"Runway status lights: automatic red runway entrance and take-off hold lights","source":"CS ADR-DSN.M.706","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"RWYCC","definition":"Runway condition code; a number from 0 to 6 describing the effect of the surface on deceleration and directional control.","source":"Reg. (EU) No 139/2014 Annex I (38b)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"safety investigation","definition":"Process of gathering and analysing information, drawing conclusions and making safety recommendations, to prevent accidents and incidents.","source":"Reg. (EU) No 996/2010 Art. 2(14)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"},"anchor":"letter-S"},{"term":"safety investigation authority (SIA)","definition":"Permanent, independent national body that conducts or supervises safety investigations.","source":"Reg. (EU) No 996/2010 Art. 4(1)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"safety pilot","definition":"A pilot licensed to act as PIC of the aircraft who keeps look-out and can take control during simulated instrument flight.","source":"SERA.3220(b); GM1 SERA.3220(b)","page":{"id":"010-05-02","title":"Rules of the air: general rules","url":"/010-air-law/05-rules-of-the-air/02-rules-of-the-air-general-rules/"}},{"term":"safety recommendation","definition":"Proposal by an SIA, intended to prevent accidents and incidents. It creates no presumption of blame or liability.","source":"Reg. (EU) No 996/2010 Art. 2(15), 17(3)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"safety-sensitive personnel","definition":"People who might endanger aviation safety if they do their job improperly (crew, maintenance, aerodrome, rescue and fire-fighting staff, controllers…).","source":"SERA Article 2(116)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"SAR aircraft","definition":"Aircraft with specialised equipment for efficient SAR missions.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"SAR facility","definition":"Any mobile resource used for SAR, including designated SAR units.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"SAR point of contact (SPOC)","definition":"Point designated by a State to receive Cospas-Sarsat distress data (24-hour from 26 Nov 2026).","source":"Annex 12, 3.2.5; Reg. (EU) 2017/373 (GM text, ear-atm-ans L15837)","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"SAR services unit (EU)","definition":"Generic term for RCC, rescue sub-centre or alerting post.","source":"Reg. (EU) 2017/373 Annex I (90)","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"SAR unit","definition":"Mobile resource of trained people with suitable equipment for expeditious SAR operations.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"SARPs","definition":"International standards and recommended practices adopted by ICAO and designated as Annexes.","source":"Arts 37, 54(l)","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"screening","definition":"Applying technical or other means to identify or detect prohibited articles.","source":"Reg. (EC) No 300/2008 Art. 3(8)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"Search","definition":"Operation, normally coordinated by an RCC/RSC, to locate persons in distress.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"search and rescue region (SRR)","definition":"Area of defined dimensions, linked to one RCC, in which SAR services are provided.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"Search and rescue service","definition":"Distress monitoring, communication, coordination and SAR functions, initial medical assistance or evacuation, using public and private resources.","source":"Annex 12 Ch. 1","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"Secretary General","definition":"ICAO's chief executive officer, appointed by the Council; heads the Secretariat.","source":"Art. 54(h)","page":{"id":"010-01-02","title":"ICAO: objectives and composition","url":"/010-air-law/01-chicago-convention-and-icao/02-icao-objectives-and-composition/"}},{"term":"security control","definition":"Any means by which the introduction of prohibited articles may be prevented.","source":"Reg. (EC) No 300/2008 Art. 3(9)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"security occurrence / security incident","definition":"A security-related event that may reduce security. An incident is an occurrence that affects, or could affect, people's safety.","source":"Reg. (EC) No 300/2008 Annex II point 1.1(15)-(16)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"security restricted area (SRA)","definition":"The part of airside where access is restricted and further security standards also apply.","source":"Reg. (EC) No 300/2008 Art. 3(13)","page":{"id":"010-11-01","title":"Aviation security: aims and objectives","url":"/010-air-law/11-security/01-aviation-security-aims-and-objectives/"}},{"term":"SEP aeroplane","definition":"Single-engine, single-pilot aeroplane without type rating, driven by a piston, electric or hybrid engine system; class ratings SEP(land) and SEP(sea).","source":"Article 2(8c); GM1 FCL.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"SEP class rating","definition":"Class rating for single-engine, single-pilot aeroplanes without a type rating. Valid for 2 years unless the operational suitability data (OSD) says otherwise.","source":"Article 2(8c); GM1 FCL.010; FCL.740(a)(1)","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"Sequenced flashing lights","definition":"Approach centre line flashing lights firing twice a second from outer to inner","source":"CS ADR-DSN.M.630(c)(7)","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"serious incident","definition":"Incident whose circumstances show a high probability of an accident, in the same window.","source":"Reg. (EU) No 996/2010 Art. 2(16)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"serious injury","definition":"Injury suffered in an accident that meets one of six criteria, such as a hospital stay of more than 48 hours starting within 7 days of the injury.","source":"Reg. (EU) No 996/2010 Art. 2(17)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"signal area","definition":"An area on an aerodrome where ground signals are displayed.","source":"SERA Article 2(120)","page":null},{"term":"signal panel","definition":"Panel displayed in the signal area to convey a visual ground signal.","source":"GM1 ADR-DSN.K.505","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"signalling lamp","definition":"Hand-aimed lamp in the control tower that produces red, green and white light signals.","source":"CS ADR-DSN.K.500","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"signalman / marshaller","definition":"A trained, approved person who guides aircraft on the ground with standard hand signals.","source":"SERA.3301(c), (d); GM1 to App. 1(4.1)(d)","page":null},{"term":"Situation display","definition":"Controller's electronic display of aircraft position and movement","source":"Reg. (EU) 2017/373 Annex I (233)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"skeletal object","definition":"A lattice or open-frame structure, such as a pylon, that is marked with bands when it is over 1.5 m in one dimension.","source":"CS ADR-DSN.Q.845(b)(2)(ii) (term used, not defined)","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"Skill test / proficiency check","definition":"Skill test demonstrates skill for the issue of a licence or rating. Proficiency check demonstrates skill to revalidate or renew.","source":"FCL.010","page":{"id":"010-04-01","title":"Personnel licensing: Annex 1, Part-FCL and Part-MED","url":"/010-air-law/04-personnel-licensing/01-personnel-licensing-annex-1-part-fcl-and-part-med/"}},{"term":"Slippery wet runway","definition":"Wet runway with friction found to be degraded over a significant portion.","source":"Reg. 139/2014 Annex I (41a)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"Slush","definition":"Snow so saturated that water drains from it when picked up.","source":"Reg. 139/2014 Annex I (38h)(e)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"SMGCS","definition":"Surface movement guidance and control system: the aerodrome's system of guidance and control for surface movement, which signs support.","source":"CS ADR-DSN.N.775(b)(1) (term used, not defined in text read)","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"SNOWTAM","definition":"A special-series NOTAM, in standard format, that reports snow, ice, slush, frost or water on the movement area.","source":"Reg. (EU) 2017/373 Annex I (231)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"Sovereignty (airspace)","definition":"A State's complete and exclusive authority over the airspace above its territory.","source":"Art. 1","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"Special air-report","definition":"Met report from an aircraft in flight, issued against set criteria","source":"Reg. (EU) 2017/373 Annex I (95)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"special code","definition":"A code with a fixed meaning, selected to indicate an emergency, radio-communication failure or unlawful interference (7700, 7600, 7500).","source":"SERA.13005(a)(1)–(3)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"special VFR","definition":"A VFR flight with an ATC clearance to operate in a control zone (CTR) in weather below VMC.","source":"SERA Article 2(122); SERA.5010","page":null},{"term":"Special VFR flight","definition":"A VFR flight cleared by ATC to fly in a CTR in weather below VMC.","source":"SERA Art. 2(122)","page":{"id":"010-05-03","title":"Visual flight rules","url":"/010-air-law/05-rules-of-the-air/03-visual-flight-rules/"}},{"term":"Specially prepared winter runway","definition":"Dry frozen compacted-snow/ice runway treated (sand, grit or mechanically) to improve friction.","source":"Reg. 139/2014 Annex I (41c)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"squelch","definition":"Receiver control that mutes the audio until the incoming signal exceeds a threshold, so weak signals are not heard.","source":"","page":{"id":"010-10-01","title":"Search and rescue: definitions and pilot procedures","url":"/010-air-law/10-search-and-rescue/01-search-and-rescue-definitions-and-pilot-procedures/"}},{"term":"SSR","definition":"Radar system of ground interrogators and airborne transponders.","source":"SERA Art. 2(118)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"stand (aircraft stand)","definition":"A designated parking position on an apron, allocated to suit the aircraft type.","source":"ADR.OPS.D.025","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"Standard (standardised) phraseology","definition":"The fixed words and phrases set out for a situation, which must be used whenever they exist.","source":"SERA.14001; Appendix 1 to AMC1 SERA.14001","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"standard phraseology","definition":"The fixed words and phrases set out for a situation, which must be used whenever they exist.","source":"SERA.14001; Appendix 1 to AMC1 SERA.14001","page":{"id":"010-07-05","title":"ATS phraseologies","url":"/010-air-law/07-air-traffic-services/05-ats-phraseologies/"}},{"term":"standard setting","definition":"The subscale setting of 1013.2 hPa, at which the altimeter reads flight levels.","source":"GM1 SERA Article 2(78)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"Standing water","definition":"Water deeper than 3 mm.","source":"Reg. 139/2014 Annex I (38h)(f)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"State aircraft","definition":"Aircraft used in military, customs and police services; outside the Convention.","source":"Art. 3(b)","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"state of design / state of manufacture","definition":"The State responsible for the organisation that holds the type design, or in which final assembly takes place.","source":"Annex 13 Ch. 1","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"state of occurrence","definition":"The State in whose territory the accident or incident occurs.","source":"Annex 13 Ch. 1 (used in Reg. (EU) No 996/2010 Art. 9)","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"State of registry","definition":"The State in whose register the aircraft is entered; issues or validates its certificates and crew licences.","source":"Arts 17, 31, 32","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"state of the operator","definition":"The State of the operator's principal place of business or, if none, permanent residence.","source":"Annex 13 Ch. 1","page":{"id":"010-12-01","title":"Accident and incident investigation","url":"/010-air-law/12-accident-investigation/01-accident-and-incident-investigation/"}},{"term":"STCA","definition":"Short-term conflict alert: ground system alert of potential or actual separation infringement","source":"GM2 ATS.TR.155(c)(9)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"stop bar","definition":"Lights at a holding position. Stop and hold at a lit stop bar; guidance says never to cross one that is lit.","source":"SERA.3210(d)(3); GM1 SERA.3210(d)(3)","page":null},{"term":"stopway","definition":"Defined rectangular area on the ground at the end of the TORA, prepared for stopping an aircraft in an abandoned take-off.","source":"Reg. (EU) No 139/2014 Annex I (42); CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"strayed aircraft","definition":"Aircraft significantly off its intended track, or reporting that it is lost.","source":"SERA Article 2(123)","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"surface craft","definition":"A ship or boat on the water (as opposed to an aircraft), which may be directed to, or itself be, a craft in distress.","source":"Annex 12, Appendix 1 (usage)","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"}},{"term":"surface in sight","definition":"The pilot sees the ground or water. SERA gives no definition; this is a plain-language explanation, not a defined term.","source":"SERA.5001, Table S5-1; SERA.5005(c)(3)(iii)","page":null},{"term":"taxi side stripe marking","definition":"Two solid lines, each 15 cm wide and 15 cm apart, in the colour of the taxiway centre line marking. It marks the edge of the load-bearing pavement.","source":"CS ADR-DSN.R.860","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"},"anchor":"letter-T"},{"term":"Territory","definition":"A State's land areas and adjacent territorial waters under its sovereignty, suzerainty, protection or mandate.","source":"Art. 2","page":{"id":"010-01-01","title":"Chicago Convention, Part I: air navigation","url":"/010-air-law/01-chicago-convention-and-icao/01-chicago-convention-part-i-air-navigation/"}},{"term":"threshold","definition":"Beginning of the part of the runway usable for landing.","source":"CS ADR-DSN.A.002; Annex 14 Ch. 1","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"threshold marking","definition":"A pattern of identical white longitudinal stripes placed symmetrically about the runway centre line at the threshold.","source":"CS ADR-DSN.L.535(a)-(b)","page":{"id":"010-09-03","title":"Aerodrome markings","url":"/010-air-law/09-aerodromes/03-aerodrome-markings/"}},{"term":"TODA","definition":"TORA plus the clearway, if provided.","source":"Reg. (EU) No 139/2014 Annex I (43)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"TORA","definition":"Runway length declared available and suitable for the ground run of an aeroplane taking off.","source":"Reg. (EU) No 139/2014 Annex I (44)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"Touchdown zone","definition":"Part of the runway beyond the threshold where landing aeroplanes are meant to touch down first.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"track","definition":"The projection of the aircraft's path on the earth's surface; direction in degrees from true, magnetic or grid north.","source":"SERA Article 2(130)","page":{"id":"010-05-01","title":"Rules of the air: definitions and applicability","url":"/010-air-law/05-rules-of-the-air/01-rules-of-the-air-definitions-and-applicability/"}},{"term":"Traffic avoidance advice","definition":"ATS advice on manoeuvres to avoid a collision","source":"SERA Article 2(131)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"Traffic information","definition":"ATS information alerting a pilot to nearby known or observed traffic, to help avoid collision","source":"SERA Article 2(132)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"Transfer of control point","definition":"Point where ATC responsibility passes to the next unit or position","source":"SERA Article 2(133)","page":{"id":"010-07-01","title":"Air traffic services: definitions and general provisions","url":"/010-air-law/07-air-traffic-services/01-air-traffic-services-definitions-and-general-provisions/"}},{"term":"transition altitude","definition":"The altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes.","source":"SERA Article 2(134)","page":null},{"term":"transition layer","definition":"The airspace between the transition altitude and the transition level (term used, not defined, in SERA).","source":"SERA.8015(eb)(1)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"transition level (TL)","definition":"The lowest flight level available for use above the transition altitude.","source":"SERA Article 2(135)","page":{"id":"010-06-01","title":"Altimeter setting procedures","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/01-altimeter-setting-procedures/"}},{"term":"Transponder","definition":"Airborne part of SSR that replies to interrogations (with code, altitude, identity depending on mode).","source":"","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"transponder mandatory zone (TMZ)","definition":"Airspace where all flights carry and operate a Mode A+C or Mode S transponder.","source":"SERA.6005(b)","page":null},{"term":"trigger NOTAM","definition":"A NOTAM that announces an AIP amendment or supplement published under AIRAC, in force from the same date and time as that change.","source":"AIS.OR.510(b); AIS.TR.510(f)-(j)","page":{"id":"010-08-01","title":"Aeronautical information: AIP, NOTAM, AIRAC and AIC","url":"/010-air-law/08-aeronautical-information-service/01-aeronautical-information-aip-notam-airac-and-aic/"}},{"term":"Type certificate (TC)","definition":"EASA's approval of a design, including its operating limitations and instructions for continued airworthiness.","source":"21.A.41","page":{"id":"010-02-01","title":"Airworthiness and the certificate of airworthiness","url":"/010-air-law/02-airworthiness-of-aircraft/01-airworthiness-and-the-certificate-of-airworthiness/"}},{"term":"uncertainty phase (INCERFA)","definition":"Uncertainty exists about the safety of an aircraft and its occupants.","source":"Reg. (EU) 2017/373 Annex I (251); ATS.TR.405(b)(1)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"},"anchor":"letter-U"},{"term":"unidentified aircraft","definition":"An aircraft seen or reported in an area whose identity has not been established.","source":"SERA Article 2(137)","page":{"id":"010-05-05","title":"Interception of civil aircraft","url":"/010-air-law/05-rules-of-the-air/05-interception-of-civil-aircraft/"}},{"term":"unlawful interference","definition":"Interference with an aircraft that the pilot signals with code 7500; code 7700 can be used instead when circumstances warrant.","source":"SERA.13005(a)(3)","page":{"id":"010-06-02","title":"Transponder operating procedures and phraseology","url":"/010-air-law/06-altimeter-setting-and-transponder-procedures/02-transponder-operating-procedures-and-phraseology/"}},{"term":"unserviceability marker / light","definition":"A cone, flag or striped board (marker), or a steady red light of at least 10 cd (light), that outlines an unserviceable or closed area.","source":"CS ADR-DSN.R.870","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"unserviceable area","definition":"A part of a taxiway, apron or holding bay that is unfit for aircraft movement, but that aircraft can safely go around. It is shown by unserviceability markers and lights.","source":"AMC1 ADR.OPS.B.070(c)(5); CS ADR-DSN.R.870","page":{"id":"010-09-06","title":"Obstacles and restricted-use areas","url":"/010-air-law/09-aerodromes/06-obstacles-and-restricted-use-areas/"}},{"term":"urgency","definition":"A state of difficulty, or a very urgent safety message, without need for immediate assistance. Signals include PAN PAN and XXX.","source":"SERA App. 1, 1.3","page":null},{"term":"UTC","definition":"Coordinated Universal Time, the time standard used in aviation, on the 24-hour clock.","source":"SERA.3401(a)","page":{"id":"010-05-02","title":"Rules of the air: general rules","url":"/010-air-law/05-rules-of-the-air/02-rules-of-the-air-general-rules/"}},{"term":"Variable message sign","definition":"A sign able to show several predetermined messages, or none.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"},"anchor":"letter-V"},{"term":"variable white","definition":"White used for lights whose intensity is varied.","source":"CS ADR-DSN.U.930(c)(3)","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}},{"term":"Vectoring","definition":"Navigational guidance as specific headings, based on surveillance","source":"Reg. (EU) 2017/373 Annex I (253)","page":{"id":"010-07-03","title":"Radar services","url":"/010-air-law/07-air-traffic-services/03-radar-services/"}},{"term":"VFR flight","definition":"A flight flown under the visual flight rules.","source":"SERA Article 2(140)","page":null},{"term":"VFR on top","definition":"VFR flight above a cloud layer. At night it is possible above the low band, after the pilot considers the GM factors.","source":"GM1 SERA.5005(c)(3)(iii)","page":null},{"term":"VHF emergency frequency","definition":"121.500 MHz, reserved for genuine emergency purposes.","source":"SERA Art. 4a; ATS.OR.405","page":{"id":"010-07-06","title":"Emergencies, communication failure and contingencies","url":"/010-air-law/07-air-traffic-services/06-emergencies-communication-failure-and-contingencies/"}},{"term":"visibility","definition":"The greater of two distances - the distance at which a suitable black object near the ground is seen and recognised against a bright background, and the distance at which lights of about 1 000 cd are seen and identified against an unlit background.","source":"SERA Article 2(141); GM1 Article 2(141)","page":null},{"term":"Visual aids","definition":"Indicators and signalling devices, markings, lights, signs and markers, or combinations of them.","source":"CS ADR-DSN.A.002","page":{"id":"010-09-05","title":"Aerodrome signs","url":"/010-air-law/09-aerodromes/05-aerodrome-signs/"}},{"term":"visual docking guidance system","definition":"A stand system that guides the pilot onto the stand and shows where to stop.","source":"AMC1/AMC2 ADR.OPS.D.035(b); GM1 ADR.OPS.D.025(b)(2)","page":{"id":"010-09-07","title":"Rescue and fire fighting, apron management","url":"/010-air-law/09-aerodromes/07-rescue-and-fire-fighting-apron-management/"}},{"term":"visual meteorological conditions (VMC)","definition":"Weather conditions, described by visibility, distance from cloud and ceiling, at or better than the specified minima.","source":"SERA Article 2(142)","page":null},{"term":"VOLMET / VOLMET broadcast","definition":"Meteorological information for aircraft in flight / continuous voice broadcast of current METAR, SPECI, TAF and SIGMET.","source":"Reg. (EU) 2017/373 Annex I (257), (258)","page":{"id":"010-07-04","title":"Flight information service and alerting service","url":"/010-air-law/07-air-traffic-services/04-flight-information-service-and-alerting-service/"}},{"term":"Wake / astern","definition":"The disturbed water behind a moving vessel / behind the vessel; the aircraft crosses it close astern for \"no longer required\".","source":"Annex 12, Appendix 1.2 (usage)","page":{"id":"010-10-02","title":"Search and rescue signals","url":"/010-air-law/10-search-and-rescue/02-search-and-rescue-signals/"},"anchor":"letter-W"},{"term":"Wake turbulence category","definition":"Grouping of aircraft types (J, H, M, L) by MCTOM for wake minima","source":"AMC1 SERA.8012","page":{"id":"010-07-02","title":"Aerodrome control and visual separation near aerodromes","url":"/010-air-law/07-air-traffic-services/02-aerodrome-control-and-visual-separation-near-aerodromes/"}},{"term":"Wet runway","definition":"Runway with visible dampness or water up to and including 3 mm deep.","source":"Reg. 139/2014 Annex I (49)","page":{"id":"010-09-01","title":"Aerodromes: definitions and aerodrome data","url":"/010-air-law/09-aerodromes/01-aerodromes-definitions-and-aerodrome-data/"}},{"term":"wind direction indicator","definition":"Fabric truncated cone on a pivot that shows the surface wind direction and a general indication of wind speed. Also called a wind sleeve, wind cone or windsock.","source":"CS ADR-DSN.K.490","page":{"id":"010-09-02","title":"Indicators, signalling devices and markers","url":"/010-air-law/09-aerodromes/02-indicators-signalling-devices-and-markers/"}},{"term":"Wing bar","definition":"Group of at least five green lights extending outward from each side of the threshold","source":"CS ADR-DSN.M.680(d)","page":{"id":"010-09-04","title":"Aerodrome lights","url":"/010-air-law/09-aerodromes/04-aerodrome-lights/"}}]