AMC1 ATS.TR.155(c)(1) ATS surveillance services

METHODS OF IDENTIFICATION

Identification of aircraft should be established by at least one of the following methods:

(a)     ADS-B identification procedures

         Where ADS-B is used for identification, aircraft may be identified by one or more of the following procedures:

(1)     direct recognition of the aircraft identification in an ADS-B label;

(2)     transfer of ADS-B identification; and

(3)     observation of compliance with an instruction to ‘TRANSMIT ADS-B IDENT’.

(b)     SSR and/or MLAT identification procedures

(1)     Where SSR and/or MLAT is used for identification, aircraft may be identified by one or more of the following procedures:

(i)      recognition of the aircraft identification in an SSR and/or MLAT label, in accordance with point (b) of ATS.OR.446;

(ii)     recognition of an assigned discrete code, the setting of which has been verified, in an SSR and/or MLAT label, in accordance with point (b) of ATS.OR.446, and in particular with points (e) to (i) of Appendix 1 to Part-ATS;

(iii)     direct recognition of the aircraft identification of a Mode S-equipped aircraft in an SSR and/or MLAT label, in accordance with point (b) of ATS.OR.446, and in particular points with (a) to (d) of Appendix 1 to Part-ATS, unless otherwise prescribed by the competent authority for the use of this method for the identification of local flights;

(iv)     by transfer of identification;

(v)      observation of compliance with an instruction to set a specific code; and

(vi)     observation of compliance with an instruction to squawk ‘IDENT’.

(2)     When a discrete code has been assigned to an aircraft, a check should be made at the earliest opportunity to ensure that the code set by the pilot is identical to that assigned for the flight. Only after this check has been made, the discrete code should be used as a basis for identification.

(c)      PSR identification procedures

(1)     Where PSR is used for identification, aircraft may be identified by one or more of the following procedures:

(i)      by correlating a particular radar position indication with an aircraft reporting its position over, or as bearing and distance from, a point shown on the situation display, and by ascertaining that the track of the particular radar position is consistent with the aircraft path or reported heading;

(ii)     by correlating an observed radar position indication with an aircraft which is known to have just departed, provided that the identification is established within 2 km (1 NM) from the end of the runway used. Particular care should be taken to avoid confusion with aircraft holding over or overflying the aerodrome, or with aircraft departing from or making a missed approach over adjacent runways;

(iii)     by transfer of identification;

(iv)     when air traffic control service is provided, by ascertaining the aircraft heading, if circumstances require, and following a period of track observation:

(A)     instructing the pilot to execute one or more changes of heading of 30 degrees or more and correlating the movements of one particular radar position indication with the aircraft’s acknowledged execution of the instructions given; or

(B)     correlating the movements of a particular radar position indication with manoeuvres currently executed by an aircraft having so reported.

(2)     When using these methods, the air traffic controller/FIS officer/AFIS officer, as appropriate, should:

(i)      verify that the movements of not more than one radar position indication correspond with those of the aircraft; and

(ii)     ensure that the manoeuvre(s) will not carry the aircraft outside the coverage of the radar or the situation display.

(d)     Additional identification method

         When two or more position indications are observed in close proximity, or are observed to be making similar movements at the same time, or when doubt exists as to the identity of a position indication for any other reason, the identification procedure in point (c)(1)(iv) should be used (only in case of air traffic control service provision), or additional methods of identification should be employed, until all risk of error in identification is eliminated.