ENR 1.9  AIR TRAFFIC FLOW MANAGEMENT (ATFM)

1 Introduction
1.1 The objective of Air Traffic Flow Management (ATFM) is to ensure an optimum flow of air traffic to/from Hong Kong International Airport (HKIA), Macao International Airport (MIA) and traffic overflying Hong Kong FIR through all sectors. ATFM supports the ATC objective of safe, orderly and expeditious flow of air traffic by ensuring the amount of traffic handled is compatible with airspace and airport capacity.
1.2 The early anticipation of capacity constraints and dissemination of ATFM measures will greatly assist upstream ACCs and Towers in complying with even stringent flow measures. Tactical ATFM measures to handle adverse weather conditions or major traffic disruptions can facilitate the delay notification process and diversion planning of Airspace Users (AU).
2 ATFM Operations within Hong Kong FIR and the Hong Kong Air Traffic Flow Management Unit
2.1 The contents in this chapter provides a general overview of ATFM services in Hong Kong FIR managed by the Hong Kong ATFM Unit (ATFMU). These include ATFM measures defined in ICAO’s Manual on Collaborative ATFM (Doc 9971), Ground Delay Programme (GDP), GDP for airport and airspace constraints, coordination during GDP, Hong Kong ATFM Notice, integration of ATFM and A-CDM, Hong Kong ATFM Website and the contact information of Hong Kong ATFMU. The associated ATFM Daily Plan (ADP), NOTAM, AIC, etc. should be referenced for supplementary information.
2.2  ATFM Measures as Defined in ICAO’s Manual on Collaborative ATFM (Doc 9971)
2.2.1 ATFM serves to balance air traffic demand against ATM resources for both airport and airspace by implementing appropriate ATFM measures. Hong Kong ATFMU may implement the following ATFM measures to resolve a capacity-demand imbalance situation or to facilitate ATC flow restrictions originating from neighbouring ACC, with an aim to enable efficient and effective air traffic management.
  1. Airborne Holding - Aircraft required to hold at a waypoint in a pre-defined holding pattern.
  2. MINutes-In-Trail (MINIT) - A tactical ATFM measure expressed as the number of minutes between successive aircraft at an airspace boundary point (FIR entry and exit fixes).
  3. Miles-In-Trail (MIT) - A tactical ATFM measure expressed as the distance in nautical miles between successive aircraft at an airspace boundary point (FIR entry and exit fixes).
  4. Reroute - A route-based ATFM measure with the aim to reroute a number of flights scheduled to arrive at a constrained ATM resource. Re-routings are usually organized in scenarios and can be mandatory or advisory.
  5. Arrival/Departure Fix Balancing - Re-routing aircraft to different fixes or holding patterns (also known as ‘stack-swap’) to redistribute demand.
  6. Minimum Departure Interval (MDI) - A time-based departure flow rate to restrict the number of departures at a particular airport.
  7. Level Capping - Aircraft are restricted to a specified flight level so as to balance airspace demand against capacity.
  8. Ground Stop (GS) - A tactical ATFM measure taken in reaction to an unpredicted adverse situation, where selected aircraft are to remain on the ground of the departure point.
  9. Ground Delay Programme (GDP) for Airport Constraint - GDP is the most efficient way in dealing with demand and capacity imbalance. It is an ATFM measure where aircraft are held on the ground in order to manage capacity and demand at a specific aerodrome. In the process, Calculated Take Off Times (CTOT) are assigned. The main factor for determining if a GDP is required is the landing capacity available called the Airport Acceptance Rate (AAR). When the AAR is reduced by inclement weather, large volume of traffic or aircraft incident, the ATFMU will institute a GDP. Specific timing of GDP will be promulgated through the ADP.
  10. GDP for Waypoint or Airspace Constraint, also known as Airspace Flow Programme (AFP) - Flights held on the ground to manage demand in a specific volume of airspace or over a waypoint.
2.3  GDP CTOT Compliance Window
2.3.1 Hong Kong ATFMU or other ATFMUs in the APAC region will target to distribute CTOT at least 90 minutes before the EOBT of constrained flights.
2.3.2  GDP for Airport Constraint (HKIA & MIA)

CTOT compliance window for airport constraint is -5/+10 minutes.

2.3.3  GDP for Waypoint or Airspace Constraint

CTOT compliance window for waypoint or airspace constraint is -5/+5 minutes.

2.3.4 Despite the compliance window, ATC will release departures as close as possible to the assigned CTOT for effective flow management. Compliance of operators to assigned CTOTs during the ATFM operation is essential and contributes to the realization of the ATFM plan. Good compliance will also assist in the reduction of the need for tactical airborne delay, thereby promoting safe and expeditious air traffic control.
2.3.5 In order to secure a CTOT during GDP, operators are reminded to file FPLs at least 3 hours before the EOBT and strictly adhere to the procedures as stipulated in ENR 1.10 para 2, “Procedures for the Submission of a Flight Plan and Subsequent Changes for Flights Departing HKIA”. Late submission of FPL may result in additional delay.
2.4  Coordination during GDP
2.4.1 Prior coordination between the initiating ATFMU (the unit which initiates the GDP) and the facilitating ATFMU should be directed if the departure cannot comply with the assigned CTOT within the compliance window.
2.4.2 In this regard, the rules of thumb to obtain a revised CTOT are as follows:
  1. Before the cabin door of a departure is closed, the AU shall notify Hong Kong ATFMU who will in turn coordinate with the initiating ATFMU for a revised CTOT.
  2. After the cabin door is closed:
    1. Hong Kong ATC (e.g. Clearance Delivery or Ground Control) shall notify Hong Kong ATFMU who will in turn coordinate with the initiating ATFMU for a revised CTOT.
    2. Pilot-In-Command (PIC) has the responsibility to ensure that a revised CTOT has been coordinated with the initiating ATFMU and to inform Hong Kong ATC if a revised CTOT has not been received.
2.4.3 In the spirit of providing an equitable service, Hong Kong ATFMU will not normally entertain a request for an earlier CTOT, except under exceptional circumstances.
2.5  Hong Kong ATFM Notice
2.5.1 In order to timely promulgate essential ATFM related information on special events/activities to local stakeholders, Hong Kong ATFMU issues a special notice via email called Hong Kong ATFM Notice.
2.5.2 The notice provides detailed information of special events, along with relevant ATFM measures to stakeholders for early planning and to enhance situational awareness.
2.5.3 The notice contains a description of the event, details of the ATFM measures to expect and any other relevant information that would impact the operation of the flight, airport operator, ATC operations, ground handling agents, etc.
2.5.4 A sample of a Hong Kong ATFM Notice is shown below for reference:

2.5.5 Local stakeholders who would like to be included in the recipient list should email to Hong Kong ATFMU (
hkatfmu@cad.gov.hk
).
2.6  Integration of ATFM and A-CDM
2.6.1 Airport Collaborative Decision Making (A-CDM) is a concept aimed at improving overall operational efficiency by reducing delays, enhancing predictability of events during the progress of a flight, sharing of timely and accurate operational data and optimizing use of resources.
2.6.2 A-CDM operation has been implemented at HKIA since 1 November 2018. The operation is based on the use of an A-CDM system to keep track of A-CDM milestones and to calculate updated and accurate times for various phases of the flight for use by all stakeholders. Details of the processes and associated procedures can be found at the website
https://extranet.hongkongairport.com by selecting “PROCEDURE MANUAL” then “A-CDM Operations Guidelines”.
2.6.3 ATFM and A-CDM are collaborative processes aimed at improving efficiency and optimizing resources in the airspace and the airport. The integration and exchange of operational information between the two processes with collaborative procedures is essential in maintaining an accurate demand picture from ATC’s perspective and to enhance situational awareness for effective decision making and traffic management by all stakeholders.
2.6.4 As part of the A-CDM milestone approach, it is essential for AU to maintain an updated Target Off Block Time (TOBT) as per the A-CDM Operations Guidelines in order to generate a respective Target Start-up Approval Time (TSAT) for AU’s reference, and for ATC to calculate and issue an accurate CTOT to regulated flights.
2.7  Hong Kong ATFM Website
2.7.1 The Hong Kong ATFM Website (
https://www.atfmc.gov.hk/
) which has been in operation from June 2020, aims to provide stakeholders the most updated ATFM information affecting flights operating to/from airports within the Hong Kong ATFM Node and transiting Hong Kong FIR. CTOT information distributed by emails and Slot Allocation Messages (SAM) via AFTN for HKIA & MIA under the Hong Kong Node would be posted to the website to complement coverage and to improve data accessibility.
2.7.2 AU can contact Hong Kong ATFMU (
hkatfmu@cad.gov.hk
) for creating an account to access specific functions within the Hong Kong ATFM Website. After creating an account, AUs can reference information of the flight, check if there are any updates on the airport status, waypoint status and view updated ADPs in the APAC region.
2.7.3 Hong Kong ATFMU will endeavour to keep the contents of the website updated. However, due to rapidly changing circumstances and events, information may not be always updated in a timely manner. Website users are advised to be cautious when using the information and to cross check with supplementary information from the associated ADP, NOTAM, AIC, emails, etc. Hong Kong ATFMU takes no responsibility for the accuracy of information received from external parties.
2.7.4 A link to a ‘User Guide’ is available in the website for reference.
2.8  Requests for Exemption from ATFM Measures
2.8.1 A flight requesting exemption from ATFM measures for reasons other than those that shall be given automatic exemption i.e. SAR, HEAD, STATE, HUM, HOSP, MEDEVAC and aircraft experiencing emergency situation should obtain prior approval for exemption from the appropriate ATS authority(s) and indicate in the flight plan the reason for special handling in the ICAO designator as ‘STS/ATFMX’ in item 18 (For more details on flight planning requirement, please refer to ENR 1.10.)

Note: The presence of one single ICAO designator for automatic exemption in the flight plan is sufficient. It is not required to include ATFMX after the single designator e.g. STS/SAR shall be filed, not STS/SAR ATFMX.

2.8.2 A remark should be included in the designator RMK/ for which FIR(s) the ATFMX exemption applies.
2.8.3 If authorization from the ATS authority(s) has not been obtained, ATFMX cannot be used. Instead, a remark should be included in the designator RMK/.
2.9  Hong Kong ATFMU Contact Information
2.9.1 ATFM of Hong Kong FIR is provided by ATFMU of Hong Kong ATCC.
2.9.2 ATFM service is provided H24. The contact details of Hong Kong ATFMU are as follows:
Unit Name Telephone Fax AFTN
Hong Kong
ATFMU 		Primary point of contact:
+852 2910 6859 Duty Flow Manager
Secondary point of contact:
+852 2910 6275 Hong Kong ATFMU		 +852 2910 1177 VHHKZDZX
e-mail
hkatfmu@cad.gov.hk
Website
https://www.atfmc.gov.hk
3 Asia Pacific Regional ATFM
3.1  Asia/Pacific Cross Border Multi-Nodal ATFM Collaboration (AMNAC)
3.1.1 Hong Kong ATFMU is a member of a research collaboration group in the APAC region, AMNAC. The research focuses on the operational concept for cross-border ATFM as a means to balance demand and capacity in order to allow a sustainable growth in traffic demand in the near future.
3.1.2 Following the development of processes and procedures to enable cross-border ATFM and several rounds of testing and validation through the conduct of operational trials, a regional framework for collaborative ATFM and common operating procedures has been adopted and implemented among the states.
3.1.3 Hong Kong ATFMU is a Level 3 ATFM Node, meaning it has the capability to generate, deliver and receive CTOTs, and it is obligated to comply with CTOTs received from other Level 3 ATFM nodes in the region.
3.1.4 More information about AMNAC is available at the following website
https://www.atfmc.gov.hk/info.html
.
3.2  Bay of Bengal Cooperative ATFM (BOBCAT)
3.2.1 The States of the ICAO Asia Pacific Region within the Bay of Bengal, South Asia and Pakistan airspace have implemented an automated ATFM service under the auspices of the ICAO Bay of Bengal ATS Coordination Group - ATFM Task Force.
3.2.2  Provision of ATFM Services for Flights Transiting Kabul FIR (BOBCAT ATFM)
3.2.2.1 Bangkok ATFMU provides ATFM service for all westbound flights intending to transit Kabul FIR between 2000 UTC and 2359 UTC daily so as to reduce ground and en-route delays, maximize capacity and optimize air traffic flow. The service provided includes calculation, promulgation, and management of mandatory CTOT and flight level, ATS route, and Calculated Time Over (CTO) at entry waypoint for entry into Kabul FIR for each affected flight.
3.2.2.2 Hong Kong ATC retains responsibility for the tactical management of flights that are subjected to this ATFM measure and facilitates the compliance as much as practicable. In discharging tactical responsibilities, non-compliant flights may be delayed by using delayed pushback and startup clearances.
3.2.3  Flights Exempted from BOBCAT ATFM
3.2.3.1 The following flights are exempted from the BOBCAT ATFM procedures:
  1. Flights experiencing an emergency, including aircraft subjected to unlawful interference;
  2. Flights on search and rescue or fire-fighting missions;
  3. Urgent medical evacuation flights or humanitarian flights specifically declared by State medical authorities that flight delays would put the life of patients aboard at risk; and
  4. Flights with “Head of State” status.

Note: After medical flights have completed their mission, they should be subject to ATFM measures. Scheduled passenger transfer flights are, by their nature, non-urgent and should not be given priority under normal operational situation.

3.2.3.2 Flights exempted from ATFM procedures shall indicate the exemption in their flight plan as follows,
(STS/ATFMX in item 18).
3.2.4  BOBCAT ATFM Operating Procedures
3.2.4.1 All affected flights are required to submit slot requests to the BOBCAT system by logging into
https://www.bobcat.aero
between 0001 UTC and 1200 UTC on the day of flight and completing the electronic templates provided.
3.2.4.2 Affected operators who do not have dedicated BOBCAT username / password access should complete the application form provided and fax the form to Bangkok ATFMU as soon as possible.
3.2.4.3 SLOT ALLOCATION PROCESS
3.2.4.3.1 The slot allocation is divided into 3 phases, namely: the slot request submission, initial slot allocation, and slot distribution to aircraft operators and ANSPs. Details can be found at
https://www.bobcat.aero/
.
3.2.5  Aircraft Operator / Pilot-in-Command and ANSP Responsibilities

Aircraft Operator / Pilot-in-Command

3.2.5.1 In accordance with ICAO PANS ATM provisions, it is the responsibility of the Pilot-in-Command (PIC) and the aircraft operator to ensure that the aircraft is ready to taxi in time to meet any required departure time. PIC shall be kept informed by their operators of the CTOT, CTO at Kabul FIR entry waypoint, and flight parameters (route, flight level) allocated by BOBCAT.
3.2.5.2 The PIC, in collaboration with ATC, shall arrange take-off as close as possible to CTOT in order to meet the allocated CTO at Kabul FIR entry waypoint.

ANSPs

3.2.5.3 In accordance with ICAO PANS ATM provisions, flights with an ATFM slot allocation should be given priority for takeoff to facilitate compliance with CTOT.
3.2.5.4 CTOT shall be included as part of the initial ATC clearance. In collaboration with the PIC, Aerodrome Control shall ensure that every opportunity and assistance is granted to a flight to meet CTOT and allocated CTO at Kabul FIR entry waypoint.
3.2.6  Coordination Procedure between Aircraft Operator / Pilot-in-Command, ANSPs, and Bangkok ATFMU
3.2.6.1 Bangkok ATFMU (VTBBZDZX) shall be included in the list of AFTN addressees for ATS messages (e.g. FPL, DEP, DLA, CHG, CNL) relating to flights subject to ATFM procedures.
3.2.6.2 Prior to departure and before obtaining an ATC Clearance, in circumstances where it becomes obvious that the allocated Kabul FIR slot parameters will not be met, a new slot allocation should be obtained as soon as possible. To avoid frequency congestion, this should be obtained primarily via aircraft operators / flight dispatchers; otherwise Ground Control or Clearance Delivery may be asked for assistance in the coordination with Bangkok ATFMU as an alternative. Early advice that the allocated Kabul FIR slot parameters will be missed also enables the slots so vacated to be efficiently reassigned to other flights.
3.2.6.3 The PIC shall include the CTOT in the initial ATC clearance request.
3.2.6.4 A missed slot results in considerable increase in coordination workload for ATC and PIC and should be avoided. To minimize coordination workload in obtaining a revised slot allocation, if the flight is still at the gate and an ATC Clearance has been obtained, PIC shall advise Ground Control of the missed slot and obtains new CTOT as specified in paragraph 3.2.6.2. If it becomes essential, the ATC Clearance may be cancelled.
3.2.6.5 Prior to departure and after the aircraft has left the gate, in the event that the aircraft is unable to meet the allocated Kabul FIR slot parameters, when requested by the PIC, Aerodrome Control shall assist the PIC in coordination with Bangkok ACC and ATFMU for a revised slot allocation.
3.2.6.6 PIC shall adjust cruise flight to comply with slot parameters at the Kabul FIR entry waypoint, requesting appropriate ATC clearances including speed variations in accordance with published AIP requirements.
3.2.7  B OBCAT ATFM Operations for Departing Aircraft from HKIA
3.2.7.1 To increase the effectiveness for departing aircraft from HKIA during the BOBCAT ATFM period and to ensure priority departure in accordance with CTOT, the following procedures are required for all BOBCAT ATFM-related flights:
  1. Before obtaining an ATC Clearance, ensure the flight is ready at least 25 minutes prior to the allocated CTOT (the additional 5-minute buffer to CTOT should not be taken into account under this provision);
  2. Notwithstanding the above; there may be some occasions where, due to the location of the aircraft’s parking bay, the aircraft could take less time to taxi than the Standard Taxi Time (STT) used by the BOBCAT system. In these cases, ATC may delay pushback and start-up procedures in order for the aircraft to have a smooth transition to the holding point.
3.2.8  BOBCAT ATFM Users Handbook
3.2.8.1 Supporting documentation, including detailed information in respect of the BOBCAT ATFM operations described above and other pertinent information has been included in the Bay of Bengal and South Asia ATFM Handbook (the “ATFM Users Handbook”), available at
https://www.bobcat.aero
.
3.2.8.2 ANSPs and aircraft operators shall ensure that they are conversant with and able to apply the relevant procedures described in the ATFM Users Handbook.
3.2.9  Bangkok ATFMU Contact Information
3.2.9.1 Bangkok ATFMU is staffed 24 hours and may be contacted via the following: