ENR 1.8  REGIONAL SUPPLEMENTARY PROCEDURES

The supplementary procedures in force are given in their entirely; "differences" are printed in capital letters.

1.  Assignment of cruising level to IFR flights within controlled airspace

Unless otherwise specified in 10.5 or authorized by the area Air Traffic Services Units cruising levels to be assigned to IFR flight within controlled airspace will be as given in the table in Appendix 3 to Annex 2.

2.  Reporting of position and air-to-ground watch

All aircraft on VFR flights and aircraft on IFR flights outside controlled airspace, must maintain a watch on a radio station furnishing communications for the Bangkok Area Control Centre and file that station information as to their position unless not equipped with suitable two-way radio communications or unless otherwise authorized. The last position reported before passing from Bangkok Flight Information Region to an adjacent Flight Information Region must also be addressed to the Air Traffic Services Unit providing Flight Information Service or Air Traffic Control Service within the Flight Information Region the aircraft is entering.

3.  Alerting and search and rescue services

The procedures for "Alerting Service" detailed in the PANS-ATM (Doc 4444) are applicable to:

  1. all flights provided with air traffic control service; and

  2. all flights within uncontrolled airspace within the Bangkok Flight Information Region (BKK FIR), which shall be provided by the Air Traffic Control unit responsible for the area.

4.  Flight Information Service

In so far as practicable Air Traffic Services units responsible for the provision of Flight Information Service over water areas must include, at the pilot's request, any available information regarding surface vessels such as radio call signs, positions, true track, speed etc. Responsibility for Flight Information Service passes from Centre to Centre at the time the aircraft crosses the Flight Information Region boundary. When adequate point-to-point communications do not exist with adjacent Flight Information Regions, Flight Information Service will be provided as far as practicable by the Centre to an aircraft leaving Bangkok FIR until reliable communication contact has been established with the Centre whose Flight Information Region it is entering

5.  Air Traffic Service coordination

Coordination procedures are in accordance with Regional Supplementary Procedures, supported by detailed local Letters of Agreement.

6.  Liaison with operating agencies

All instructions to aircraft from Air Traffic Services units, excluding aerodrome and approach control instructions, are transmitted by a communication network designated by the government. Instructions to aircraft from aerodrome and approach control Air Traffic Services units are routed through a government owned radio network. All area control service information or instructions issued to aircraft are made available to an operator or this designated representative as agreed between the operator and the Air Traffic Services units concerned.

7.  Air Traffic Service Messages

Flight plan messages are transmitted to the appropriate Air Traffic Services units and communication stations immediately after the flight plan is filed. However, if certain elements of the flight plan require validation by the Flight Data Management Center (FDMC) prior to distribution, the flight plan shall be distributed only after such validation has been completed. Once validated, the flight plan for flights outbound from aerodromes within the Bangkok FIR (VTBB) shall be distributed to all addresses, including the departure aerodrome, destination aerodrome, and all FIRs through which the aircraft will fly. The flight plan for flights inbound to or transiting the Bangkok FIR (VTBB) shall be distributed only to the appropriate Air Traffic Services units within the Bangkok FIR. The departure message shall be transmitted only if it is reasonably certain that it will reach the addresses in good time; in such case, it shall be transmitted immediately after the departure of the aircraft to the same addresses as the flight plan message.

For a flight through an intermediate stop, a separate flight plan (FPL) shall be submitted for each individual flight segment. For flights involving more than one stop, each flight plan shall be originated by the flight operation or the Air Traffic Services unit at the aerodrome of initial departure to ensure accurate data processing and air traffic management.

When the departure of an aircraft is delayed for more than 30 minutes from the estimated off-block time (EOBT) or the estimated elapsed time (EET) contained in the flight plan, A delay message (DLA) shall be originated and transmitted to all addressees of the flight plan message.

A departure message (DEP) shall be transmitted upon departure of the aircraft to:

  1. the ATS unit at the aerodrome of destination; and

  2. all relevant Area Control Centres (ACCs) or Flight Information Centres (FICs).

In accordance with FPL 2012 standards, supplementary information such as fuel endurance and the number of persons on board (Item 19) must be provided during filing for SAR purposes but may not be transmitted in the initial flight plan message.

When an arrival report is received by the ATC Unit serving the aerodrome of destination, an arrival message (ARR) will be transmitted to the same addresses as the flight plan message, provided that adequate aeronautical communication facilities are available. Where communication facilities are not available, arrival reports may be filed at alternate locations; however, the transmission of arrival messages shall be subject to applicable procedures. It should be noted that all Air Traffic Services messages are distributed by the Flight Data Management Center (FDMC).

8.  Altimeter setting procedures applicable to Air Traffic Services

Based on current and anticipated atmospheric pressure distribution, Bangkok ACC coordinates where required the lowest flight level to be used.

9.  Weather deviation procedures

9.1 In order to indicate priority, the pilot may initiate communication by stating “WEATHER DEVIATION REQUIRED”. The pilot retains the option of initiating the communications using the urgency call “PAN PAN” three times to alert all listening parties of a special handling condition which will receive ATC priority for issuance of a clearance or assistance.
9.2 When a pilot requests clearance to deviate from track, the controller shall:
  1. issue a clearance to deviate from track, if there is no conflicting traffic in the lateral dimension; or

  2. establish vertical separation and issue a clearance to deviate from track, if there is conflicting traffic in the lateral dimension; or

  3. if unable to establish vertical separation, and there is conflicting traffic in the lateral dimension;

    1. advise the pilot that clearance for the requested deviation is not available;

    2. provide traffic about, and to, all affected aircraft; and

    3. request pilot intentions.

    Note: Position may be expressed as direction and distance, or actual or estimated location or ATS route/ track code

10.  RVSM Procedures

10.1 Airworthiness and Operational Approval and Monitoring
10.1.1 APPROVAL PROCESS.

Operators must obtain airworthiness and operational approval from their States of Registry or States of Operator, as appropriate, to conduct RVSM operations.

Information regarding the process for RVSM approval is contained in, for commercial air transport operations, the Air Operator Certificate Requirements (AOCR) latest revision, or, Thailand Civil Aviation Regulation – Air Operations (TCAR OPS) Part - SPA latest revision, as applicable.

10.1.2 AIRCRAFT MONITORING.

Operators are required to participate in the RVSM aircraft monitoring program. This is an essential element of the RVSM implementation program in that it confirms that the aircraft altitude-keeping performance standard is being met.

The Guidance Material for the Continued Safety Monitoring of the Asia-Pacific RVSM Airspace is published by the Asia and Pacific Office of ICAO (https://www.icao.int/APAC/apac-electronic-documents). The purpose of this document is to describe safety monitoring activities for RVSM airspace, including the respective roles and responsibilities of States, Regional Monitoring Agencies (RMAs), and operators.

The full details on the monitoring requirements, procedures and available monitoring services are available from MAAR’s website (https://www.aerothai.co.th/maar).

Monitoring accomplished for other regions can be used to fulfill the monitoring requirements for the Asia/Pacific region. There are a number of organizations worldwide who may be able to provide monitoring services. Operators should contact MAAR for confirmation if their monitoring plans/results are acceptable.

10.2 Area of Applicability
10.2.1 RVSM shall be applicable in that volume of airspace between FL 290 and FL 410 inclusive in the Bangkok FIR.
10.3 Prior to Departure
10.3.1 An operator shall ensure that, where the flight is intended to operate in Reduced Vertical Separation Minimum (RVSM) airspace, it has the required RVSM approval.
10.3.2 The letter “W” shall be inserted in item 10 (Equipment) of the ICAO standard flight plan to indicate that both the aircraft and operator are RVSM approved.
10.3.3 The aircraft registration shall be inserted in Item 18 of the flight plan.
10.3.4 Operators of formation flights of State aircraft shall not insert the letter W in Item 10 of the ICAO flight plan form, regardless of the RVSM approval status of the aircraft concerned. Operators of formation flights of State aircraft intending to operate within the RVSM airspace specified in 10.2.1 shall include STS/NONRVSM in Item 18 of the ICAO flight plan form.
10.4 In-flight Procedures within RVSM Airspace
10.4.1 Before entering RVSM airspace, the pilot should review the status of required equipment. The following equipment should be operating normally:
  1. two primary altimetry systems. A cross-check between the primary altimeters should be made. A minimum of two will need to agree within ±60m (±200ft). Failure to meet this condition will require that the altimetry system be reported as defective and air traffic control (ATC) notified;

  2. one automatic altitude-keeping device;

  3. one altitude-alerting device; and

  4. one altitude operating transponder

10.4.2 The controller-pilot phraseologies used for in-flight RVSM operations are specified in ICAO PANS-ATM Doc 4444 (Chapter 12), as shown in the following table:
MessagePhraseology
For a controller to ascertain the RVSM approval status of an aircraft(call sign) CONFIRM RVSM APPROVED
For a pilot to report RVSM approval statusAFFIRM RVSM

For a pilot to report non-RVSM approval status:

  1. on the initial call on any frequency within the RVSM airspace (controllers shall provide and readback with this same phrase), and

  2. in all requests for flight level changes pertaining to flight levels within the RVSM airspace; and

  3. in all read-backs to flight level clearances pertaining to flight levels within the RVSM airspace

Additionally, except for State aircraft, pilot shall include this phrase to read back flight level clearances involving the vertical transit through FL 290 or FL 410

NEGATIVE RVSM
For a pilot of a non-RVSM approved State aircraft to report non-RVSM approval status, in response to the phrase (call sign) CONFIRM RVSM APPROVED.NEGATIVE RVSM [(supplementary information, e.g. STATE AIRCRAFT)]
For a controller to deny of clearance into the RVSM airspace(call sign) UNABLE ISSUE CLEARANCE INTO RVSM AIRSPACE, MAINTAIN
[or DESCEND TO, or CLIMB TO]
(level)
For a pilot to report when severe turbulence affects the aircraft’s capability to maintain the height-keeping requirements for RVSM.UNABLE RVSM DUE TURBULENCE

For a pilot to report that the aircraft’s equipment has degraded en-route below that required for flight within the RVSM airspace. (See Appendix A)

(This phrase is to be used to convey both the initial indication of the non-MASPS compliance, and henceforth, on initial contact on all frequencies within the lateral limits of the RVSM airspace until such time as the problem ceases to exist, or the aircraft has exited the RVSM airspace.)

UNABLE RVSM DUE EQUIPMENT
For a controller to request an aircraft to provide information as soon as RVSM-approved status has been regained or the pilot is ready to resume RVSM operationsREPORT WHEN ABLE TO RESUME RVSM
For a controller to request confirmation that an aircraft has regained RVSM-approved status or a pilot is ready to resume RVSM operationsCONFIRM ABLE TO RESUME RVSM
For a pilot to report the ability to resume operations within the RVSM airspace after an equipment or weather-related contingency.READY TO RESUME RVSM
  • Example 1:

    • A non-RVSM approved aircraft, maintaining FL 260, subsequently requests a climb to FL 320.

    • Pilot: (call sign) REQUEST FL 320, NEGATIVE RVSM

    • Controller: (call sign) CLIMB TO FL 320

    • Pilot: (call sign) CILMB TO FL 320, NEGATIVE RVSM

  • Example 2:

    • A non-RVSM approved aircraft, maintaining FL 260, subsequently requests a climb to FL 430.

    • Pilot: (call sign) REQUEST FL 430, NEGATIVE RVSM

    • Controller: (call sign) CLIMB TO FL 430

    • Pilot: (call sign) CILMB TO FL 430, NEGATIVE RVSM

  • Example 3:

    • A non-RVSM approved aircraft, maintaining FL 360, subsequently requests a climb to FL380.

    • Pilot: (call sign) REQUEST FL 380, NEGATIVE RVSM

    • Controller: (call sign) CLIMB TO FL 380

    • Pilot: (call sign) CILMB TO FL 380, NEGATIVE RVSM

  • Example 4:

    • A non-RVSM approved civil aircraft, maintaining FL 280, subsequently requests a climb to FL320.

    • Pilot: (call sign) REQUEST FL 320, NEGATIVE RVSM

    • Controller: (call sign) UNABLE ISSUE CLEARANCE INTO RVSM AIRSPACE, MAINTAIN FL 280

10.4.3 During cleared transition between levels, the aircraft should not overshoot or undershoot the assigned FL by more than 150 ft (45m).
10.4.4 The pilot must notify ATC when the aircraft’s equipment has degraded below the requirement in 10.4.1.
  1. When informed by the pilot of an RVSM-approved aircraft operating in RVSM airspace that the aircraft’s equipment no longer meets the RVSM requirements, ATC shall consider the aircraft as non-RVSM-approved.

  2. The pilot shall inform ATC, as soon as practicable, of any restoration of the proper functioning of equipment required to meet the RVSM requirements.

  3. The first ACC to become aware of a change in an aircraft’s RVSM status shall coordinate with adjacent ACCs, as appropriate.

Scenario 1: All automatic altitude control systems fail (e.g., Automatic Altitude Hold).

The Pilot shouldATC can be expected to
Initially, maintain CFL and evaluate the aircraft’s capability to maintain altitude through manual control. 
Subsequently, watch for conflicting traffic both visually and by reference to ACAS, if equipped. 

If considered necessary, alert nearby aircraft by

  1. Making maximum use of exterior lights;

  2. Broadcasting position, FL, and intentions on 121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency, 123.45 MHz, may be used.)

 
Notify ATC of the failure and intended course of action. Possible courses of action include:Obtain pilot’s intentions, and pass essential traffic information.
  1. Maintaining the CFL and route, provided that the aircraft can maintain level.

  2. Requesting ATC clearance to climb above or descend below RVSM airspace if the aircraft cannot maintain CFL and ATC cannot establish lateral, longitudinal or conventional vertical separation.

  3. Executing the contingency manoeuvre shown in 9.4, if ATC clearance cannot be obtained and the aircraft cannot maintain CFL.

  1. If the pilot intends to continue in RVSM airspace, assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or conventional vertical separation, and if so, apply the appropriate minimum

  2. If the pilot requests clearance to exit RVSM airspace, accommodate expeditiously, if possible.

  3. If adequate separation cannot be established and it is not possible to comply with the pilot’s request for clearance to exit RVSM airspace, advise the pilot of essential traffic information, notify other aircraft in the vicinity and continue to monitor the situation.

  4. Notify adjoining ATC facilities/sectors of the situation.

Scenario 2: Loss of redundancy in primary altimetry systems

The Pilot shouldATC can be expected to
If the remaining altimetry system is functioning normally, couple that system to the automatic altitude control system, notify ATC of the loss of redundancy and maintain vigilance of altitude keeping.Acknowledge the situation and continue to monitor progress.

Scenario 3: All primary altimetry systems are considered unreliable or fail

The Pilot shouldATC can be expected to
Maintain CFL by reference to the standby altimeter (if the aircraft is so equipped). 

Alert nearby aircraft by

  1. Making maximum use of exterior lights;

  2. Broadcasting position, FL, and intentions on 121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency, 123.45 MHz, may be used.)

 
Consider declaring an emergency. Notify ATC of the failure and intended course of action. Possible courses of action include: Obtain pilot’s intentions, and pass essential traffic information.
  1. Maintaining CFL and route, provided that ATC can provide lateral, longitudinal or conventional vertical separation.

  2. Requesting ATC clearance to climb above or descend below RVSM airspace if ATC cannot establish adequate separation from other aircraft.

  3. Executing the contingency manoeuvre shown in 9.4, if ATC clearance cannot be obtained.

  1. If the pilot intends to continue in RVSM airspace, assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or conventional vertical separation, and if so, apply the appropriate minimum.

  2. If the pilot requests clearance to exit RVSM airspace, accommodate expeditiously, if possible.

  3. If adequate separation cannot be established and it is not possible to comply with the pilot’s request for clearance to exit RVSM airspace, advise the pilot of essential traffic information, notify other aircraft in the vicinity and continue to monitor the situation.

  4. Notify adjoining ATC facilities/sectors of the situation.

Scenario 4: The primary altimeters diverge by more than 200 FT (60 m)

The Pilot should
Determine the defective system through the normal airplane integrated comparator warning system or in the absence of such a system, establish trouble-shooting procedures comparing the primary altimeters to the standby altimeter (corrected using the correction card)
If the defective system can be determined, couple the functioning altimeter to the altitude keeping device in use.
If the defective system cannot be determined, follow the guidance in Scenario 3 for failure or unreliable altimeter indications of all primary altimeters
10.4.5 When the aircraft encounters severe turbulence:
10.4.5.1 Forecast
  1. When a meteorological forecast is predicting severe turbulence, ATC shall determine whether RVSM should be suspended and, if so, for how long and for which specific flight level(s) and/or area.

  2. In cases where RVSM will be suspended, the ACC suspending RVSM shall coordinate with adjacent ACCs with regard to the flight levels appropriate for the transfer of traffic; unless a contingency flight level allocation scheme has been determined by letter of agreement. The ACC suspending RVSM shall also coordinate applicable sector capabilities with adjacent ACCs as appropriate.

10.4.5.2 Not forecast
  1. When an aircraft operating in RVSM airspace encounters severe turbulence due to weather or wake vortex that the pilot believes will impact the aircraft’s capability to maintain its cleared flight level, the pilot shall inform ATC. ATC shall establish either an appropriate horizontal separation or an increased minimum vertical separation.

  2. ATC shall, to the extent possible, accommodate pilot requests for flight level and/or route changes and shall pass on traffic information as required.

  3. ATC shall solicit reports from other aircraft to determine whether RVSM should be suspended entirely or within a specific flight level band and/or area.

  4. ACC suspending RVSM shall coordinate such suspension(s) with, and any required adjustments to, sector capabilities with adjacent ACCs, as appropriate, to ensure an orderly progression to the transfer of traffic.

Scenario 5: Turbulence (greater than moderate), which the pilot believes, will impact the aircraft’s capability to maintain flight level.

The Pilot shouldATC can be expected to
Watch for conflicting traffic both visually and by reference to ACAS, if equipped. 

If considered necessary, alert nearby aircraft by

  1. Making maximum use of exterior lights;

  2. Broadcasting position, FL, and intentions on 121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency, 123.45 MHz, may be used.)

 
Notify ATC of intended course of action as soon as possible. Possible courses of action include: 
  1. Maintaining CFL and route, provided that ATC can provide lateral, longitudinal or conventional vertical separation.

  2. Requesting flight level change, if necessary.

  3. Executing the contingency manoeuvre shown in 9.4, if ATC clearance cannot be obtained and the aircraft cannot maintain CFL.

  1. Assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or conventional vertical separation, and if so, apply the appropriate minimum.

  2. If unable to provide adequate separation, advise the pilot of essential traffic information and request pilot’s intentions.

  3. Notify other aircraft in the vicinity and continue to monitor the situation.

  4. Notify adjoining ATC facilities/sectors of the situation.

10.5 Procedures for Operation of Non-RVSM Compliant Aircraft in RVSM airspace
10.5.1 RVSM approved aircraft will be given priority for level allocation over non-RVSM approved aircraft.
10.5.2 The vertical separation minimum between non-RVSM compliant aircraft operating in the RVSM stratum and all other aircraft is 2 000 ft.
10.5.3 Non-RVSM compliant aircraft operating in RVSM airspace should use the phraseology contained in ICAO PANS-ATM Doc 4444 (Chapter 12). A pilot of a non-RVSM approved State aircraft to report non-RVSM approval status, in response to the phrase (call sign) CONFIRM RVSM APPROVED, shall respond with “NEGATIVE RVSM [(supplementary information, e.g. STATE AIRCRAFT)]”
10.5.4 Non-RVSM compliant aircraft may be cleared to climb to and operate above FL410 or descend to and operate below FL290 provided that they:
  1. Do not climb or descend at less than the normal rate for the aircraft; and

  2. Do not level off at an intermediate level while passing through the RVSM stratum.

10.5.5 Non-RVSM compliant aircraft may not flight plan between FL290 and FL410 inclusive within RVSM airspace, except for the following situations:
  1. The aircraft is being initially delivered to the State of Registry or Operator; or

  2. The aircraft was RVSM approved but has experienced an equipment failure and is being flown to a maintenance facility for repair in order to meet RVSM requirements and/or obtain approval; or

  3. The aircraft is transporting a spare engine mounted under the wing; or

  4. The aircraft is being utilized for mercy or humanitarian purposes; or

  5. State aircraft (those aircraft used in military, custom and police services shall be deemed state aircraft)

Note: The procedures are intended exclusively for the purposes indicated and not as a means to circumvent the normal RVSM approval process.

10.5.6 The assignment of cruising levels to non-RVSM compliant aircraft shall be subjected to an ATC clearance. Aircraft operators shall include the “STS/ Category of operations (i.e. FERRY/HUMANITARIAN/MILITARY/CUSTOMS/POLICE)/NONRVSM)” in Field 18 of the ICAO Flight Plan.
10.6 Procedures for Suspension of RVSM
10.6.1 Air traffic services will consider suspending RVSM procedures within affected areas of the Bangkok FIR when there are pilot reports of greater than moderate turbulence. Within areas where RVSM procedures are suspended, the vertical separation minimum between all aircraft will be 2 000 ft.
10.7  Flight Level Allocation Scheme (FLAS) For South China Sea Area
10.7.1 The following flight levels on the routes listed below can be used without pre-departure clearances from the downstream ATS units (no-PDC levels):
ATS Route

No-Pre-Departure Coordination (No-PDC) Flight Levels

Other levels available with prior approval

L880

FL330, FL370, FL410
M633 FL340
N891

SB – FL290, FL310, FL330

NB – ALL EVEN

A1

EB – FL330, FL370, FL410

WB – ALL EVEN

N506

FL270, FL330, FL410

P629 FL260, FL320
A202

EB – FL290, FL330, FL370, FL410

WB – ALL EVEN

10.8 Reporting of Large Height Deviation (LHD)

Civil Aviation Organisation and Operators shall submit safety reports in accordance with CIVIL AVIATION AUTHORITY OF THAILAND REQUIREMENT ON REPORTING OF CIVIL AVIATION OCCURRENCES. The List of Mandatory Occurrence Reporting under CAAT REQUIREMENT encompasses those occurrences which can be identified as LHDs such as

  1. level bust;

  2. malfunction or defect of any indication system when this results in misleading indications to the crew;

  3. unsafe ATC (Air Traffic Control) clearance;

  4. conflicting instructions from different ATS Units potentially leading to a loss of separation;

  5. intentional deviation from ATC instruction which has or could have endangered the aircraft, its occupants or any other person;

  6. uncontrollable cabin pressure;

  7. ACAS/TCAS RAs (Airborne/Traffic Collision Avoidance System, Resolution Advisory);

  8. wake-turbulence encounters; and

  9. call sign confusion related occurrences.

More details are available from MAAR’s website (https://www.aerothai.co.th/maar/safetylhd.php).

11.  TRAFFIC INFORMATION BROADCASTS BY AIRCRAFT (TIBA) AND RELATED OPERATING PROCEDURES

11.1 TIBA Procedures
11.1.1 Special procedures have been developed for pilot use in active contingency zones if communications are significantly degraded or unavailable, These TIBA procedures supersede and take the place of lost communication procedures that are outlined in Annex 2 to the Chicago Convention and PANS-ATM (DOC 4444) and will enable traffic information broadcasts by aircraft (TIBA) to be made as well as providing collision hazard information. When aircraft will enter designated airspace in which it is known in advance that normal communication is not available, pilots should maintain a listening watch on the TIBA frequency 10 minutes prior to entering that airspace until leaving the airspace.
11.1.2 For an aircraft taking off from an aerodrome located within the lateral limits of the designated airspace listening watch should start as soon as appropriate after take-off and be maintained until leaving the airspace.
11.2 Times of Broadcast

When a loss of normal communications requires TIBA procedures to be implemented, pilots shall make broadcasts in English on 128.95 MHz as follows:

  1. At the time the loss of normal communications is recognized;

  2. 10 minutes before entering a designated airspace when it is known in advance that normal communications will not be available within that airspace or, for a pilot taking off from an aerodrome located within the lateral limits of the designated airspace, as soon as appropriate after take-off;

  3. 10 minutes prior to crossing a reporting point;

  4. 10 minutes prior to crossing or joining an ATS route;

  5. at 20 minutes intervals between distant reporting points;

  6. 2 to 5 minutes, where possible, before a change in flight level;

  7. at the of a change in flight level; and

  8. at any other time considered necessary by the pilot.

Note: Normal position reporting procedures should be continued at all times, regardless of any action taken to initiate or acknowledge a traffic information broadcast.

11.3 Broadcast Format

TIBA broadcasts should be made using the following phraseology:

  1. For other than those indicating changes in flight level:

    ALL STATIONS (call sign) FLIGHT LEVEL (number) [of CLIMBING TO FLIGHT LEVEL (number)] (direction) (ATS route) [or DIRECT FROM (position) TO (position) POSITION] (position) AT (time) ESTIMATING (next reporting point, or the point of crossing or joining a designated ATS route) AT (time) (call sign) FLIGHT LEVEL (number) (direction)

    Example: “ALL STATIONS WINDAR 671 FLIGHT LEVEL 380 NORTHWEST BOUND A464 POSITION 80 MILES SOUTH EAST OF KEVOK AT 2358 ESTIMATING KOBAS AT 0020 WINDAR 671 FLIGHT LEVEL 380 NORTHWEST BOUND OUT”

    Note: For broadcasts made when the aircraft is not near an ATS significant point, the position should be given as accurately as possible and in any case to the nearest 30 minutes of latitude and longitude.

  2. Before a change in flight level:

    ALL STATIONS (call sign) (direction) (ATS route) [or DIRECT FROM (position) TO (position)] LEAVING FLIGHT LEVEL (number) FOR FLIGHT LEVEL (number) AT (position and time)

  3. At the time of a change in flight level:

    ALL STATIONS (call sign) (direction) (ATS route) [or DIRECT FROM (position) TO (position)] LEAVING FLIGHT LEVEL (number) NOW FOR FLIGHT LEVEL (number) followed by: ALL STATIONS (call sign) MAINTAINING FLIGHT LEVEL (number)

  4. When reporting a temporary flight level change to avoid an imminent collision risk:

    ALL STATIONS (call sign) LEAVING FLIGHT LEVEL (number) NOW FOR FLIGHT LEVEL (number) followed as soon as practicable by: ALL STATIONS (call sign) RETURNING TO FLIGHT LEVEL (number) NOW

11.4 Acknowledgement of the Broadcasts

TIBA broadcasts should not be acknowledged unless a potential collision risk is perceived.

11.5 Cruising Level Changes
11.5.1 Cruising level changes should not be made within the designated airspace, unless considered necessary by pilots to avoid traffic conflicts, to climb to minimum en-route or safe altitudes, to overcome operational limitations, to avoid adverse weather, or in response to an operational emergency
11.5.2 When cruising level changes are unavoidable, all available aircraft lighting which would improve the visual detection of the aircraft should be displayed while changing levels.
11.6 Collision Avoidance

If, on receipt of a traffic information broadcast from another aircraft, a pilot decides that immediate action is necessary to avoid an imminent collision risk, and this cannot be achieved in accordance with the right-of-way provisions of Annex 2 to the Chicago Convention, the pilot should:

  1. unless an alternative manoeuvre appears more appropriate, immediately descend 150 m (500 ft), or 300 m (1 000 ft) if above FL 290 in an area where a vertical separation minimum of 600 m (2 000 ft) is applied:

  2. display all available aircraft lighting which would improve the visual detection of the aircraft;

  3. as soon as possible, reply to the broadcast advising action being taken;

  4. notify the action taken on the appropriate ATS frequency and

  5. as soon as practicable, resume normal flight level, notifying the action on the appropriate ATS frequency.

11.7 Operation of Transponders

When implementing TIBA procedures, pilots shall operate aircraft transponders on Mode A and C at all time. In the absence of alternative instructions from the appropriate ATS unit, aircraft not assigned a discrete code should squawk code 3300.

11.8 Operation of TCAS

Unless otherwise directed by an appropriate authority, pilots should operate TCAS in TA/RA Mode at maximum range setting during the cruise phase of flight and at a range setting appropriate to the traffic situation when in the departure or terminal phases of flight.

11.9 Special Operations

Specific aircraft may need to be involved in special operations during the period when a FIR is an activated contingency zone. These aircraft may therefore be unable to utilize the contingency route structure for a significant period of their flights, Aircraft that will be classified as special operations are as follows:

  1. Special operations of State aircraft

  2. Aircraft in emergency situations or operating with significant reduction in operating efficiency

  3. Mercy flights and aircraft engaged in search and rescue, medical evacuation, and

  4. coastal surveillance operations.

11.10 Activation and Cancellation of TIBA Procedures

This procedure shall be included in AIP Supplements or NOTAM on TIBA procedures and will be cancelled by NOTAM.

12.  OPERATING PROCEDURES FOR WESTBOUND FLIGHTS BETWEEN BANGKOK FIR AND YANGON FIR ON ROUTES L507, P646, N895, L524, L301, L301 DWI P762, M502 LALIT P762, M626, L515 AND L759

12.1 For a pair of outbound aircraft from the Bangkok FIR and transiting into the Yangon FIR, 50 NM longitudinal separation minima may be applied between suitably equipped aircraft which are approved for RNP10 operations utilizing ADS-C/CPDLC or VHF communications under the following conditions:
12.1.1 50 NM longitudinal separation may be applied between RNP10 approved aircraft with DCPC (VHF or CPDLC) operating on L507.
12.1.2 50 NM longitudinal separation may be applied between RNP10 approved aircraft, equipped with serviceable ADS-C/CPDLC, operating on L507, P646, N895, L524, L301, L301 DWI P762, M502 LALIT P762, M626 L515 AND L759.

a) To ensure ADS-C/CPDLC serviceability before applying 50 NM longitudinal separation, pilot of westbound traffic intending to operate on P646, N895, L524, L301, L301 DWI P762 AND M502 LALIT P762 shall log on to Yangon CPDLC (VYYF) at least 50 NM before entering Yangon FIR and inform Bangkok ATC upon CPDLC is successfully established with VYYF.

b) 50 NM longitudinal separation using ADS-C/CPDLC between a pair of aircraft may be applied, both aircraft shall ensure their ADS-C/CPDLC serviceability and successfully log on to Yangon CPDLC (VYYF).

c) For flights intended to land within Yangon FIR, ADS-C/CPDLC will not be required.

12.2 Pilots are to advise ATC of any deterioration or failure of navigation system below the navigation requirements for RNP10 or unavailability of CPDLC. ATC shall then provide alternate separation and/or alternative routing.
12.3 Aircraft meeting RNP10 navigation requirements shall indicate /R in item 10a and indicate PBN/A1 in item 18 of the ICAO flight plan format.
12.4 CPDLC-equipped aircraft shall indicate data link descriptors (/J1-7) in item 10a of ICAO flight plan format.