ENR 1.6  ATS SURVEILLANCE SERVICES AND PROCEDURES

1.  ATS SURVEILLANCE SERVICES

1.1  General
1.1.1 ATS Surveillance Services is the predominant means of control at Bangkok Area Control Centre and Approach Control Units at Don Mueang, Suvarnabhumi, Chiang Mai, Hat Yai, Hua Hin, Krabi, Nakhon Si Thammarat, Phitsanulok, Phuket, Sukhothai, Surat Thani, Samui and Ubon Ratchathani provided in accordance with ICAO Doc 4444 Air Traffic Management (PANS-ATM) Chapter 8.
1.1.2 ADS-B is used to complement the existing radars in order to increase the reliability and coverage of the ATS surveillance service.
7 ADS-B stations are located at Ubon Ratchathani_1, Ubon Ratchathani_2, Samui, Doi Inthanon, Hat Yai, Phuket, and Surat Thani. These stations mostly cover the current radar coverage. However, Doi Inthanon station, due to its better location, has a coverage beyond the current Chiang Mai radar site.
1.1.3 In case radar cannot be used by air traffic controllers due to any reasons, ADS-B will be used to provide surveillance service only for the aircraft that have been approved for ADS-B operations.
1.1.4 Radio Communications procedures
Stations ServiceCallsign

Bangkok Area Control Centre

Bangkok Approach Control Unit

Chiang Mai Approach Control Unit

Hat Yai Approach Control Unit

Hua Hin Approach Control Unit

Krabi Approach Control Unit

Nakhon Si Thammarat Approach Control Unit

Phitsanulok Approach Control Unit

Phuket Approach Control Unit

Sukhothai Approach Control Unit

Surat Thani Approach Control Unit

Samui Approach Control Unit

Ubon Ratchathani Approach Control Unit

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Procedural and ATS Surveillance

Bangkok Control

Bangkok Approach

Chiang Mai Approach

Hat Yai Approach

Hua Hin Approach

Krabi Approach

Nakhon Si Thammarat Approach

Phitsanulok Approach

Phuket Approach

Sukhothai Approach

Surat Thani Approach

Samui Approach

Ubon Approach

1.2  Application of ATS Surveillance Control Service
1.2.1 ATS Surveillance identification is achieved according to the provisions specified by ICAO Doc 4444 Air Traffic Management (PANS-ATM) Chapter 8.
1.2.2 ATS Surveillance service is provided in controlled airspace to aircraft operating within Bangkok, Chiang Mai, Hat Yai, Hua Hin, Krabi, Nakhon Si Thammarat, Phitsanulok, Phuket, Sukhothai, Surat Thani, Samui and Ubon Ratchathani TMAs/CTRs and along all airways.
1.2.3 ATS Surveillance service in respect of unknown aircraft:

  1. In controlled airspace, traffic information will be given when an identified controlled flight is observed to be on a conflicting path with an aircraft which ATC have no specific information deemed to constitute a collision hazard, a course of avoiding action will be suggested, if so requested by the pilot or if in the opinion of ATC the situation warrants.

  2. When an identified IFR operating outside controlled airspace is observed to be on a conflicting path with another aircraft, the identified aircraft will be advised of the need for collision avoidance. If so requested by the pilot or if in the opinion of ATC the situation warrants, a course of avoiding action will be suggested.

  3. In both cases mentioned in 1.2.3 a) and b) the decision as to whether or not to comply with the ATC suggestion rests solely with the pilot.

  4. Whenever suggestion to assist the pilot for avoiding action is given, the consideration will be given if practicable to the rules of the air, but pilot are nevertheless reminded that they are ultimately responsible for the prevention of collision.

1.2.4 Separation Minima (Horizontal) based on ATS Surveillance Systems are:

  1. 5 NM en-routes along airways, and

  2. 5 NM in Bangkok, Chiang Mai, Hat Yai, Hua Hin, Krabi, Nakhon Si Thammarat, Phitsanulok, Phuket Sukhothai, Surat Thani, Samui and Ubon Ratchathani TMAs/CTRs.

1.2.5 Level assigned by ATC to pilot will provide a minimum terrain clearance according to the phase of flight.
1.2.6 ATS Surveillance approach procedures will be provided within Bangkok, Chiang Mai, Hat Yai, Hua Hin, Krabi, Nakhon Si Thammarat, Phitsanulok, Phuket, Sukhothai, Surat Thani, Samui and Ubon Ratchathani TMAs/CTRs.

  1. Inbound aircraft

    Inbound on airway

    Aircraft flying on the airways system will be cleared into the TMA/CTR without having to request a specific entry clearance.

  2. Inbound other than on airways

    Aircraft wishing to enter the TMAs/CTRs are required to obtain permission at least 10 minutes before reaching the zone boundary, when they will be advised of the route to be followed consistent with the current traffic situation.

  3. Initial approach procedures with ATS Surveillance control

    1. When inbound traffic is being sequenced by ATS Surveillance, the initial and intermediate approach procedures will be flown under directions from the approach ATC and will consist of the part of the approach between the zone boundary or the terminal holding fix and the final approach path. When holding procedures are not in use, ATS Surveillance sequencing may commence before the terminal holding fix.

    2. Pilots should plan their flight profile in such a manner as to be able to achieve the minimum holding level at the holding point if so required.

    3. When an aircraft is under approach ATS Surveillance control, changes of heading or flight level/altitude will be made only on instructions from ATC, except in the case of radio communication failure in the aircraft or at the ATS Surveillance unit.

    4. Heading and flight levels/altitudes at which to leave the zone boundary or holding areas will be passed by ATC. Vectoring will be given and descent clearance will include an estimate of track distance to touchdown. Further distance information will be given between the initial descent clearance and intercept heading to the ILS.

    5. Speed control may be applied on a tactical basis to the extent determined necessary by ATC. Aircraft unable to conform to the speeds specified by ATC should inform ATC immediately and state what speeds will be used. In the interests of accurate spacing, pilots are requested to comply with speed adjustment as promptly as is feasible within their own operational constraints and should advise ATC if circumstances necessitate a change of speed for aircraft performance reasons.

    6. In the event of ATS Surveillance failure, new instructions will be issued to each aircraft under ATC and the procedures as defined for intermediate approach without ATS Surveillance control will be put into effect.

  4. Initial approach procedures – without ATS Surveillance control

    When inbound traffic is not being sequenced by ATS Surveillance, aircraft will be cleared from the TMA zone boundary to carry out an instrument approach procedure appropriate for the landing direction.

  5. Outbound Aircraft

    Routes from the airport

    1. Routes may be varied at ATC discretion according to the prevailing traffic conditions.

    2. Warning: Pilots are reminded to maintain adequate terrain clearance, except when being vectored under ATS Surveillance control, in which case ATC will ensure that adequate terrain clearance exists prior to issuing vectoring.

    3. For ATC purposes, outbound aircraft will normally be required to cross a certain point at or above the altitude assigned. Pilots who cannot comply with the necessary climb profile must inform ATC in good time (i.e. before departure) so that an alternative routing can be coordinated.

    Visual reporting points

    1. To facilitate the integration of VFR flights within the controlled airspace, pilots may be required to join/leave the airspace via the specified visual reporting points.

    2. For the benefit of pilots of VFR flight who prefer to determine their position by radio navigation aids rather than by visual pin-points, the visual reporting points are suitably defined in AIP-Thailand.

1.2.6.1 Missed approaches

  1. As directed by ATC.

  2. In the absence of instructions from ATC, the procedures are as in the published charts in AIP-Thailand.

1.2.6.2 Special VFR flight

  1. Special VFR clearances for flights within the controlled airspace may be given whenever traffic conditions permit. These flights are subject to the general conditions laid down for special VFR flights.

  2. Aircraft may be given a ATS Surveillance service whist within the zone if, due to the traffic situation, ATC considers it advisable. It will remain the responsibility of the pilot to remain at all times in flight conditions which will enable pilot to determine his flight path and to keep clear of obstacles, and to ensure that he is able to comply with the relevant low flying restrictions of the rules of the air. For the pilots of fixed-wing aircraft, the pilot must inform ATC if compliance with the above entails a change of heading or height.

  3. Clearance for special VFR flight below minimum sector altitude cannot be given, unless at some specific radial or bearing which provides sufficient terrain clearance.

1.2.6.3 Holding point for ATS Surveillance service

Chiang Mai Terminal Control Area

  • Name : KARAE

  • Position : 18 DME radial 210 CMA DVOR/DME (183009.07N 0984829.42E)

  • Lower Limit : 8 000 feet QNH

  • Upper Limit : 11 000 feet QNH

  • Holding Axis : 030/210 (Inbound Track 030, Outbound Track 210)

  • Pattern : 1 minute, left hand race-track pattern

Phitsanulok Terminal Control Area

  • Name : UNITE

  • Position : 20 DME radial 050 PSL DVOR/DME (165907.21N 1003327.88E)

  • Lower Limit : 6 000 feet QNH

  • Upper Limit : 11 000 feet QNH

  • Holding Axis : 050/230 (Inbound Track 230, Outbound Track 050)

  • Pattern : 1 minute, right hand race-track pattern.

Hat Yai Terminal Control Area

  • Name : KOYAW (KYN)

  • Position : 20 DME radial 040 HTY DVOR/DME (0711.0N 10036.7E)

  • Lower Limit : 3 000 feet QNH

  • Upper Limit : 7 000 feet QNH

  • Holding Axis : 040/220 (Inbound Track 220, Outbound Track 040)

  • Pattern : 1 minute, right hand race-track pattern.

1.3  In order to maximize use of ATS Surveillance Systems located at Don Mueang, Suvarnabhumi, Chiang Mai, Chiang Rai, Chumphon, Hat Yai, Hua Hin, Phuket, Phitsanulok, Roi Et, Surat Thani, Ubon Ratchathani and Udon Thani airport, where available, surveillance is used to maximum extent practicable in the provision of approach control services. Accordingly, when within surveillance cover, identified controlled flights may expect to be under radar control.

ATC units providing approach radar control service within Bangkok, Chiang Mai, Hat Yai, Hua Hin, Krabi, Nakhon Si Thammarat, Phitsanulok, Phuket, Sukhothai, Surat Thani, Samui and Ubon Ratchathani TMAs/CTRs use the word “Bangkok Approach”, “Chiang Mai Approach”, “Hat Yai Approach”, “Hua Hin Approach”, “Krabi Approach”, “Nakhon Si Thammarat Approach”, “Phitsanulok Approach”, “Phuket Approach”, “Sukhothai Approach”, “Surat Thani Approach”, “Samui Approach” and “Ubon Approach” in his/her callsign respectively.

In addition to the application of Radar Control Service and Procedures as mentioned above, the following procedures also be applied when Secondary Surveillance Radar (SSR) may be used alone in the provision of air traffic services, including in the provision of separation between aircraft provided:

1.3.1 Regardless of weather conditions, an ATC authorization is required prior to operate within the TMAs/CTRs.
1.3.2 Unless otherwise authorized by appropriate approach control units, each aircraft must be equipped as follows:

  1. TWO-WAY radio capable of communications with approach control units on appropriate frequency.

  2. Operable radar beacon transponder.

  3. Request for deviation from the 4096 transponder equipment must be submitted to appropriate approach control units at least one hour before the proposed operation.

  4. An operable VOR, ADF or TACAN receiver.

1.3.3 Pilot of arriving aircraft should contact the appropriate approach control units on the publicized frequency and give their position, altitude, radar beacon code and destination; radio contact should be initiated far enough from the TMA boundary to preclude entering the TMA before radio communication is established.
1.3.4 IFR operation: aircraft within the TMAs/CTRs are required to operate in accordance with current IFR procedures as prescribed in Annex 2. AIP-Thailand or NOTAM and Amendment thereto.
1.3.5 VFR operation: Arriving aircraft must obtain authorization prior to entering the TMAs/CTRs and must contact appropriate approach control units on appropriate frequency. Departing aircraft require a clearance to depart the TMA and should advise the appropriate Tower of their intended cruising altitude and route of flight. ATC will normally advise VFR aircraft when leaving the geographical limit of TMA. Radar service is not automatically terminate with this advisory unless specifically state by ATC.
1.3.6 VFR aircraft outside TMAs/CTRs are cautioned against operating to closely to TMA boundaries especially when the floor of that TMA is 3000 ft or less or when VFR cruise altitude are at or near the floor of higher level. Observance at this precaution will reduce the potential for encountering TMA aircraft operation at TMA floor altitude.
1.3.7 This programme is not to be interpreted as a relief to the pilot of their responsibilities to see and avoid other traffic operating in basic VFR weather conditions and to adjust their operating in basic VFR weather conditions and to adjust their operations and flight path as necessary to preclude serious wake encounters and to or better than VMC. The appropriate approach control units should be advised and a revised clearance or instruction obtained when compliance with an assigned route, heading, and or/altitude is likely to compromise pilot responsibilities with respect to terrain and obstruction clearance, VORTEX exposure, and weather minimum.
1.3.8 ATC clearance and separation, an ATC authorization is required to enter and operate within the TMAs/CTRs for the following services:

  1. Sequencing of all arriving ATS Surveillance controlled aircraft.

  2. 5 NM ATS Surveillance separation between IFR aircraft.

  3. 5 NM ATS Surveillance separation between IFR and VFR or Special VFR aircraft.

  4. Between VFR aircraft – Traffic advisories and as appropriate safety alert, and also information to enable them to fit into the landing sequence.

1.3.9 ATS Surveillance approach control service to aircraft proceeding to the airports in this programme will be terminated at a sufficient distance to allow time to change to the appropriate tower frequency.
1.4  Radio Communication Failure
1.4.1 If two-way communication is lost with an aircraft, ATC should first determine whether or not the aircraft’s receiver is functioning by instructing the aircraft on frequency so far used to acknowledge by making a specified manoeuvre and by observing the aircraft’s track or by instructing the aircraft to operate the Special Position Identification (SPI) feature or to make the code changes. Where it has been established by the action mentioned above that the aircraft’s radio receiver is functioning, ATC will continue to provide radar services to the aircraft.
1.4.2 If the aircraft’s radio is completely unserviceable, the pilot should carry out the procedures for radio failure in accordance with ICAO provisions. If radar identification has already been established, ATC will vector other identified aircraft clear of its track until such time as the aircraft leaves radar cover .
1.5  ATS Surveillance Failure
1.5.1 In the event of ATS Surveillance failure or loss of ATS Surveillance identification, instructions will be issued to restore standard procedural separation.
1.5.2 The use of fight levels separated by 500 feet below FL290 or 1 000 feet at or above FL290 may be resorted to temporarily if standard procedural separation cannot be provided immediately.
1.5.3 ATC shall continue to control the traffic by using procedural separation.

2.  PRIMARY SURVEILLANCE RADAR

2.1  Area of Radar Coverage
2.1.1 PSRs are located at position with maximum range in accordance with the following table:
Primary Surveillance Radar StationLatitudeLongitudeRange
Suvarnabhumi International Airport134122.63N 1004613.05E40 NM
2.1.2 Hours of operation will be 24 hours except for notice for maintenance by NOTAM.
2.1.3 Graphic portrayal of area of theoretical PSR coverage as shown in Figure ENR 1.6-W to Figure ENR 1.6-Z.

3.  SECONDARY SURVEILLANCE RADAR

3.1  Area of Radar Coverage
3.1.1 SSRs are located at position with maximum range in accordance with the following table:

Secondary Surveillance Radar Stations

Latitude

Longitude

Range

Don Mueang International Airport

135532.82N

1003620.14E

256 NM

Suvarnabhumi International Airport134149.90N 1004615.44E256 NM

Chiang Mai International Airport

184534.76N 0985801.44E 256 NM

Mae Fah Luang-Chiang Rai International Airport

195734.62N

0995257.56E

256 NM

Chumphon Airport

104304.39N

0992156.76E

256 NM

Phitsanulok Airport

164559.34N

1001642.26E

256 NM

Roi Et Airport

160639.74N

1034639.87E

256 NM

Surat Thani Airport

090800.77N

0990843.50E

256 NM

Ubon Ratchathani Airport

151441.65N

1045204.87E

256 NM

Udon Thani Airport

172315.59N

1024611.72E

256 NM

Hat Yai International Airport

065608.15N

1002300.20E

256 NM

Bang Duk Hill, Phuket

080801.67N

0981946.52E

256 NM

3.1.2 Hours of operation will be 24 hours except for notice for maintenance by NOTAM.
3.1.3 Graphic portrayal of area of theoretical SSR and/or SSR/ADS-B coverage as shown in Figure ENR 1.6-A to Figure ENR 1.6-O.
3.2  Emergency Procedures
3.2.1 If the pilot of an aircraft encountering a state of emergency has previously been directed by ATC to operate the transponder on a specific code, this code setting shall be maintain until otherwise advised. In all other circumstances. The transponder shall be set to mode A/3 code 7700.
3.2.2 Notwithstanding the procedure in 3.2.1 above, a pilot may select mode A/3 code 7700 whenever the nature of the emergency is such that this appears to him to be the most suitable course of action.
3.3  Radio Communication Failure Procedures
3.3.1 In the event of an aircraft radio receiver failure, a pilot shall select mode A/3 code 7600 and follow established procedures; subsequent control of the aircraft will be based on those procedures.
3.4  Unlawful Interference
3.4.1 Should an aircraft in flight be subjected to unlawful interference, the pilot shall endeavour to set the transponder to mode A/3 code 7500 to give indication of the situation unless circumstances warrant the use of mode A/3 code 7700.
3.4.2 When a pilot has selected mode A/3 code 7500 and subsequently requested to confirm his code by ATC, he shall, according to circumstances either confirm this or not reply at all.

Note: The absence of a reply from the pilot will be taken by ATC as an indication that the use of mode A/3 code 7500 is not due to an inadvertent false code selection.

3.5  Operating Procedures
3.5.1 All aircraft flying within Bangkok FIR are required to operate their transponders in accordance with ATC instructions. They should maintain the setting of SSR codes until otherwise instructed except as provided for in 3.6.2 and 3.6.3 below.
3.5.2 Pilots of aircraft equipped with Mode S having an aircraft identification feature shall set the aircraft identification in the transponder. This setting shall correspond to the aircraft identification specified in item 7 of the ICAO flight plan, or, if no flight plan has been filed, the aircraft registration.
3.6  Code Assignment Method
3.6.1 All IFR aircraft flying within controlled airspace in Bangkok FIR shall be assigned transponder code as follows.
Flight StatusSSR codes
International flight 0700-0777, 6100-6177
Domestic flight

1260-1277, 3301-3377, 4200-4277,

4400-4477, 4500-4577, 7200-7277

3.6.2 Pilots of aircraft about to enter Bangkok FIR who have not received specific instructions from ATC concerning the setting of the transponder shall operate the transponder on mode A/3 code 3300 before entry and maintain that code setting until otherwise instructed.
3.6.3 VFR Operation
3.6.3.1 VFR flight operating in Bangkok FIR may be assigned SSR codes by ATS unit concerned.
3.6.3.2 VFR flight departing from an aerodrome without SSR code being assigned shall use mode A/3 code 2000 until a specific code is assigned by an ATS unit.

4.  AUTOMATIC DEPENDENT SURVEILLANCE-BROADCAST ADS-B

4.1  Area of ADS-B Coverage
4.1.1 ADS-B receivers are located at position with maximum range in accordance with the following table:
Automatic Dependent Surveillance Stations LatitudeLongitudeRange

Doi Inthanon

Samui

Ubon Ratchathani_1

Ubon Ratchathani_2

Phuket

Surat Thani

Hat Yai

183524.62N

092931.55N

151446.10N

151441.65N

080801.67N

090800.75N

065611.33N

0982913.78E

0995916.76E

1045209.02E

1045204.86E

0981946.51E

0990843.52E

1002344.44E

256 NM

256 NM

256 NM

256 NM

256 NM

256 NM

256 NM

4.1.2 Hours of operation will be 24 hours except for notice for maintenance by NOTAM.
4.1.3 Graphic portrayal of area of theoretical ADS-B coverage as shown in Figure ENR 1.6-P to Figure ENR 1.6-V.
4.2  Emergency Procedures
4.2.1 Pilot of aircraft encountering a state of emergency shall set their transponder as stipulated in paragraph 3.2
4.3  Radio Communication Failure Procedures
4.3.1 Aircraft experiencing total radio communication failure shall set transponder as stipulated in paragraph 3.3
4.4  Unlawful Interference
4.4.1 Pilot of aircraft in flight be subjected to unlawful interference shall set transponder as stipulated in paragraph 3.4
4.5  Operating Procedures
4.5.1 ATC will provide the ATS Surveillance service based on the information provided by ATC air situation display, which will show different symbols corresponding to the available surveillance sources. If the surveillance data is not available from any sources due to any reasons, ATC will immediately provide the Procedural separation for the aircraft.
4.5.2 The pilot-in-command, upon awareness of an onboard ADS-B equipment failure, should also inform ATC as soon as possible.
4.5.3 All relevant phraseology should follow those in Doc 4444, Procedures for Air Navigation Services - Air Traffic Management.
4.5.4 All aircraft flying within Bangkok FIR are required to operate their transponders in accordance with ATC instructions. They shall set transponder as stipulated in paragraph 3.5.
4.5.5 Pilots of aircraft equipped with Mode S having an aircraft identification feature shall set transponder as stipulated in paragraph 3.5.
4.6  Flight Planning
4.6.1 Aircraft operators intending to receive ATS surveillance service based on ADS-B (Out) when operating within Bangkok FIR should obtain the relevant operations specifications approvals from their respective States and file either “B1” or “B2” in Item 10b of their flight plans.
4.6.2 Aircraft Operators should also ensure that their flight crews are familiar with the operation of the ADS-B equipment on board the aircraft and are aware of any limitations or differences in operation compared to SSR.
4.6.3 If the ADS-B transmitter onboard the aircraft becomes inoperable or does not meet required operational approval standards and if the following actions do not affect the continued operation of the Mode S transponder responses to interrogations, the ADS-B transmitter should either be:
4.6.3.1 Deactivated; or
4.6.3.2 Set to transmit only a value of zero for the Navigation Uncertainty Category (NUCp) or Navigation Integrity Category (NIC) or Navigation Accuracy Category (NAC) or Source Integrity Limit (SIL).
4.7  Code Assignment Method
4.7.1 All aircraft flying within controlled airspace in Bangkok FIR shall set transponder as stipulated in paragraph 3.6

5.  OTHER RELEVANT INFORMATION AND PROCEDURES

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