DIRECTORATE OF AIR TRAFFIC MANAGEMENT RAJIV GANDHI BHAWAN, NEW DELHI­110003 [File No. AAI/ATM/SQMS/31‐16/2012] Doc. Id: ED/ATM/2012/311604/ATMC/PROC ATMC AIR TRAFFIC MANAGEMENT CIRCULAR NO. 4 of 2012 SSR Identification Procedures 1.
Introduction: 1.1
Presently all ATS surveillance systems at AAI ATC centres/airports have capability to assign discrete SSR code to each aircraft for the designated portion of airspace and generate warnings/alerts if there are unintentionally duplicated SSR codes. These ATS surveillance systems do permit code/call sign correlation. In spite of such facilities, the radar controllers are frequently confirming squawk codes with aircraft, adding to communication congestion and increased workload for them as well as for pilots. 1.2 1.3 The operationalization of Mode S radars at Chennai (Porur), BIA Bangaluru, RGIA Hyderabad, Bellary, Bhopal, Vizag, Porbandar provides means to identify an aircraft which is Mode S‐equipped and has aircraft identification feature. Other upcoming Mode S radars including radars at Kolkata (Badu), Katihar, Jharsugudda etc would have similar features. Procedures in this ATMC are supplementary to the procedures described in Chapter 8 of Manual of Air Traffic Services – Part 1 (MATS‐1). 2.
Purpose 3.
Purpose of this ATMC is to provide guidance to controllers for application of SSR identification which will help in reducing communication congestion in radar environment. Scope: 3.1
This ATMC is applicable to all ATC Units of Airports Authority of India where Secondary Surveillance Radar (SSR) is in operation. 4.
SSR Identification Procedures: 4.1 Where SSR is used for identification, aircraft may be identified by one or more of the following procedures: Page 1 of 5 ATMC 4 of 2012 Directorate of Air Traffic Management 4.1.1 Recognition of the aircraft identification in a radar label; Note: The radar controllers need not confirm SSR code with aircraft provided a) the aircraft has been assigned discrete SSR code, b) there is no “Duplication” or “Coasting” indication, and c) code/call sign correlation has been achieved successfully, d) the track of the Radar Position Symbol (RPS) is consistent with the current flight plan of the aircraft. 4.1.2 Recognition of an assigned discrete code, the setting of which has been verified, in a radar label; Note: For application of such procedures there should not be any “Duplication” or “Coasting” indication 4.1.3 Direct recognition of the aircraft identification of a Mode S‐equipped aircraft in a radar label; Note: The controller should normally correlate the Aircraft Identification Feature with the aircraft identification entered in the flight plan and displayed to controllers on flight progress strips. This will help in avoiding any misidentification due to transmission of wrong call sign by Mode S equipped aircraft. 4.1.4 by transfer of identification; 4.1.5 observation of compliance with an instruction to set a specific code; 4.1.6 observation of compliance with an instruction to squawk IDENT. Note: Garbling of transponder replies may produce “IDENT”­type of indications. Nearly simultaneous “IDENT” transmissions within the same area may give rise to errors in identification. 4.2 When a discrete code has been assigned to an aircraft, a check shall 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 shall the discrete code be used as a basis for identification. Note: Wherever aerodrome control tower is equipped with Approach Monitor Aid, and it is observed that the Mode A code (discrete) shown on the situation display is same what has been assigned to the aircraft, it will be is deemed as verified Mode A code. There is no need for further verification of Mode A code by the concerned Approach Radar controller. However, when it is observed that the Mode A code shown on the situation display is different to what has been assigned to the aircraft; the tower controller shall immediately inform to the Approach Radar controller about the discrepancy in assigned Mode A code. In such cases, the pilot shall be requested to confirm the code selected and, if the situation warrants (e.g. not being a case of unlawful interference), to reselect the correct code. 4.3 If direction, level, speed, track or any other displayed information of an aircraft raises doubt about its identification, additional checks may be made to ensure correctness of identification. 10‐07‐2012 ED/ATM/2012/311604/ATMC/PROC Page 2 of 5 ATMC 4 of 2012 Directorate of Air Traffic Management 5 5.1 5.2 5.3 5.4 5.5 Procedures to deal with discrepancy in Mode A Code / Mode S Identification Feature: When it is observed that the Mode A code shown on the situation display is different to what has been assigned to the aircraft, the pilot shall be requested to confirm the code selected and, if the situation warrants (e.g. not being a case of unlawful interference), to reselect the correct code. If the discrepancy between assigned and displayed Mode A codes still persists, the pilot may be requested to stop the operation of the aircraft’s transponder. The next control position and any other affected unit using SSR in the provision of ATS shall be informed accordingly. Aircraft equipped with Mode S having an aircraft identification feature shall transmit the aircraft identification as specified in Item 7 of the ICAO flight plan or, when no flight plan has been filed, the aircraft registration. Whenever it is observed on the situation display that the aircraft identification transmitted by a Mode S‐equipped aircraft is different from that expected from the aircraft, the pilot shall be requested to confirm and, if necessary, re‐enter the correct aircraft identification. If, following confirmation by the pilot that the correct aircraft identification has been set on the Mode S identification feature, the discrepancy continues to exist, the following actions shall be taken by the controller: a) inform the pilot of the persistent discrepancy; b) where possible, correct the label showing the aircraft identification on the situation display; and 5.
c) notify the erroneous aircraft identification transmitted by the aircraft to the next control position and any other interested unit using Mode S for identification purposes. Phraseologies: 5.1 The phraseologies to be used for the provision of ATS surveillance services using SSR are contained in Appendix A. 5.1
Any queries or further guidance required on the contents of this ATMC should be addressed to: Executive Director [ATM] Airports Authority of India Rajiv Gandhi Bhawan Safdarjung Airport New Delhi‐110003 E‐mail: [email protected] 10‐07‐2012 ED/ATM/2012/311604/ATMC/PROC Page 3 of 5 ATMC 4 of 2012 Directorate of Air Traffic Management 6.
Validity 6.1
This ATMC will remain in force until further notice and ATMC 2 of 2009 is hereby cancelled. (VIJAYINDER K. DUTTA) EXECUTIVE DIRECTOR [ATM] AIRPORTS AUTHORITY OF INDIA Dated: 10­07­2012 10‐07‐2012 ED/ATM/2012/311604/ATMC/PROC Page 4 of 5 ATMC 4 of 2012 Directorate of Air Traffic Management APPENDIX A SECONDARY SURVEILLANCE RADAR (SSR) PHRASEOLOGIES
To request the capability of the SSR
equipment
a)
ADVISE TRANSPONDER CAPABILITY;
*b) TRANSPONDER (as shown in the flight plan);
*c)
NEGATIVE TRANSPONDER.
* Denotes pilot transmission.
To instruct setting of transponder
To request the pilot to reselect the assigned
mode and code
a)
FOR DEPARTURE SQUAWK (code);
b)
SQUAWK (code)
a)
RESET SQUAWK [(mode)] (code);
*b) RESETTING (mode) (code).
* Denotes pilot transmission.
To request reselection of Mode S aircraft
identification
To request the pilot to confirm the Code
selected on the aircraft’s transponder
RE-ENTER [ MODE S] AIRCRAFT IDENTIFICATION
a)
CONFIRM SQUAWK (code);
*b) SQUAWKING (code).
* Denotes pilot transmission.
To request the operation of the IDENT
feature
To request temporary suspension of
transponder operation
To request emergency code
a)
SQUAWK [(code)] [AND] IDENT;
b)
SQUAWK LOW;
c)
SQUAWK NORMAL
SQUAWK STANDBY.
SQUAWK MAYDAY (CODE SEVEN-SEVEN ZEROZERO]
To request termination of transponder
STOP SQUAWK
To request transmission of pressure altitude
SQUAWK CHARLIE;
To request pressure setting check and
confirmation of level
To request termination of pressure altitude
transmission because of faulty operation
CHECK ALTIMETER SETTING AND CONFIRM (level).
To request level check
CONFIRM (level).
STOP SQUAWK CHARLIE WRONG INDICATION;
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