REPUBLIC OF CHINA
AIP Supplement for Taipei FIR
Civil Aviation Administration
Air Traffic Services Division
No. 340 Dunhua N.Road
Taipei, 105, Taiwan
TEL:886-2-2349-6118
FAX:886-2-2349-6122
AFS:RCTPYAYX
Email:ais@mail.caa.gov.tw
 
AIP SUP
06/26
Effective from 16 MAR 2026
Published on 09 MAR 2026
 

AIR TRAFFIC FLOW MANAGEMENT (ATFM)

Introduction

  1. The objective of Air Traffic Flow Management is to optimize a safe, orderly, expeditious flow of air traffic to/from airports in Taipei FIR and traffic overflying Taipei FIR. Through ATFM, airspace users (AUs), Airport Operators (AOs) and ATS units (ATSUs) can be better aware of predicted delays so that timely adjustment to operations and flight schedule could be made accordingly to fulfill passenger's needs.
  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 AUs.

ATFM Operations within Taipei FIR and the Taipei ATFM Unit

  1. The contents in this chapter provides a general overview of ATFM services in Taipei FIR managed by the Taipei ATFM Unit (ATFMU).
  2. ATFM Measures as Defined in ICAO's Manual on Collaborative ATFM (Doc 9971)
    1. ATFM serves to balance air traffic demand against ATM resources for both airport and airspace by implementing appropriate ATFM measures. Taipei ATFMU may implement the following ATFM measures to resolve a demand and capacity imbalance or to manage ATC flow restrictions originating from collaborating ACC, with an aim to constitute an optimum air traffic management.
      • Airborne Holding, Radar Vector or Speed Control instructions: Aircraft required to absorb more flight time to solve demand and capacity imbalance.
      • Ground Stop (GSt): A tactical ATFM measure taken in reaction to an unpredicted adverse situation, where constrained aircraft shall remain on the ground of the departure aerodrome.
      • Ground Delay Program (GDP) for Airport Constraint: GDP is a pre-tactical or tactical ATFM measure in an ATM process 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 distributed to flights destined for the specific aerodrome. When a GDP is scheduled to last for several hours, the likelihood of slots having to be revised increases, as conditions could change. Taipei ATFM website will be the system in place to advise all stakeholders (ATSU, AUs, AOs, and ground handlers) of CTOT as well as of any changes to the GDP. The main factor for determining if a GDP is required is the Airport Acceptance Rate (AAR). When the AAR is reduced by adverse weather, large volume of traffic or aircraft incident, Taipei ATFMU may initiate a GDP. Specific timing of GDP will be announced through the ATFM Daily Plan (ADP) or NOTAM.
      • GDP for Waypoint or Airspace, also known as Airspace Flow Program (AFP): Aircraft held on the ground to manage demand against ATC capacity in a specific volume of airspace or over a waypoint.
      • Minutes-In-Trail (MINIT): A tactical ATFM measure expressed as the number of minutes between each successive aircraft at an airspace boundary point (FIR entry and exit fixes).
      • Miles-In-Trail (MIT): A tactical ATFM measure expressed as the distance in nautical miles between each successive aircraft at an airspace boundary point (FIR entry and exit fixes).
      • Minimum Departure Interval (MDI): A time-based departure flow rate to restrict the number of departures at a particular airport.
      • Reroute: A route-based ATFM measure with the aim to reroute a number of aircraft scheduled to arrive at a constrained ATM resource. 
      • Level Capping: Aircraft are restricted to a specified flight level limiting climb or descent so as to manage airspace demand against capacity.
      • Arrival/Departure Fix Balancing: Rerouting aircraft to different fixes or holding patterns to redistribute demand.
  3. Triggering of ATFM measures
    1. An ATFM measure may be triggered when there will be a demand-capacity imbalance at a particular resource. The imbalance may be caused by airspace activity, airport closure/construction, special event or adverse weather etc.
    2. Taipei ATFMU will provide notification of ATFM measure to be implemented, along with its effective period. For pre-planned events, such as air exercises, an ADP and/or NOTAM will be issued in advance to inform stakeholders of the ATFM measure. In the case of unscheduled events, such as unforeseen adverse weather or sudden foreign object damage on the runway, a NOTAM and/or revised ADP will be issued to provide notification. 
  4. CTOT Operation and CTOT Compliance Window
    1. One of the key ATFM measures used by Taipei ATFMU to balance traffic demand against limited resource capacity is GDP through the issuance of CTOT. CTOTs are calculated based on expected arrival times of flights at the congested resource, adjusted to achieve appropriate flow rate, and should provide AUs with awareness of their departure times. When GDP is activated, all relevant stakeholders are requested to adhere to the following procedure.
    2. Taipei ATFMU or other ATFMUs in the APAC region will target to distribute CTOT at least 90 minutes before the EOBT of constrained flights.
    3. CTOT compliance window for airport constraint is -5/+10 minutes.
    4. CTOT compliance window for waypoint or airspace constraint is -5/+5 minutes.
    5. Insofar as practicable, ATC will manage flights to depart as close to the CTOT as possible. Compliance of all relevant stakeholders to assigned CTOTs during the ATFM operation is essential and contributes to the realization of the ATFM. Good compliance will also assist in the reduction of the need for tactical airborne delay, thereby promoting safe and expeditious air traffic control.
    6. In order to secure a CTOT during GDP, AUs shall file FPLs at least 3 hours before the EOBT for those flights operating to/from airports in Taipei FIR or transiting through Taipei FIR except where necessary for operational and technical reasons. Late submission of FPL may result in additional delay.
  5. Coordination during GDP
    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. As a general rule, AUs, AOs and tower controllers are responsible for obtaining a revised CTOT at different times. The rules to obtain a revised CTOT are as follows:
      1. At least 15 minutes before Calculated Off-Block Time (COBT), or as soon as AU realizes that COBT cannot be met, the AU shall notify airport operator of the next feasible estimated off-block time. The airport operator shall then coordinate with Taipei ATFMU at least 5 minutes before COBT, or as soon as informed by AU, to request a revised CTOT, ensuring full consideration is given to rearranging the sequence of constrained flights.
      2. Once constrained aircraft are authorized by tower controllers to push back, tower controllers shall request a revised CTOT from the Taipei ATFMU immediately if the aircraft are expected to depart outside the CTOT compliance window.
    3. In the event of adverse weather conditions or special circumstances, tower controllers or AOs supporting CTOT operations may temporarily suspend CTOT procedures through coordination with ATFMU during the affected period or to implement alternative air traffic flow management measures as a substitute of CTOT.
  6. Taipei ATFM Website
    1. The Taipei ATFM Website
      (https://atfm.anws.gov.tw) aims to provide stakeholders the most up-to-date ATFM information affecting flights operating to/from airports within Taipei FIR and transiting Taipei FIR. CTOT information would be posted on the website to complement coverage and to improve data accessibility.
    2. Taipei ATFMU will endeavor to keep the contents of the website updated. However, due to rapidly changing circumstances and events, information may not always be updated in a timely manner. Website users are advised to be cautious when using the information and to cross-check it with supplementary information from the associated ADP, NOTAM, etc. Taipei ATFMU takes no responsibility for the accuracy of information received from external parties.
  7. Requests for Exemption from ATFM Measures
    1. The following aircraft which should be given priority over other aircraft or may be exempted from ATFM measures should indicate the reason using the ICAO designator, e.g., SAR, MEDEVAC, HOSP, HEAD, HUM, STATE, ATFMX, in item 18 of the flight plan.
      • Aircraft on a search and rescue mission;
      • Aircraft on an urgent medical evacuation specifically declared by medical authorities;
      • Aircraft with Head of State/Presidential aircraft;
      • Aircraft for mercy or humanitarian purpose;
      • State aircraft (those aircraft used in military, customs and police services should be deemed as state aircraft); or
      • Other aircraft in a state of emergency or specifically approved by the appropriate ATS authorities.
      • 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.  For example, STS/MEDEVAC shall be filed, not STS/MEDEVAC ATFMX.
    2. AUs who are uncertain whether their flights should be exempted should contact Taipei ATFMU for clarification.
  8. Taipei ATFMU Contact Information
    1. ATFM of Taipei FIR is provided by ATFMU of Taipei Area Control Center (TACC).
    2. The ATFM service is available 24 hours a day, provided by Taipei ATFMU. The contact details of Taipei ATFMU are as follows:
Unit Name Taipei ATFMU
Tel +886 3384 1090
+886 3384 1091
+886 3384 1092
Fax +886 3386 0120
AMHS RCAAZQZM
Email atfm@anws.gov.tw
Receiving CTOT RCAAZDZY
Transmitting CTOT     RCAAZDZV
ATFM Website https://atfm.anws.gov.tw