Advisory Circular (AC) No. 801-002

Air Traffic Flow Management (ATFM) Procedures

Issuing Office: Civil Aviation, Standards Document No.: AC 801-002
File Classification No.: Z 5000-34 Issue No.: 01
RDIMS No.: 20817157-V5 Effective Date: 2025-11-20

Table of contents

1.0 Introduction

  1. (1) This Advisory Circular (AC) is provided for information and guidance purposes. It describes an example of an acceptable means, but not the only means, of demonstrating compliance with regulations and standards. This AC on its own does not change, create, amend or permit deviations from regulatory requirements, nor does it establish minimum standards.

1.1 Purpose

  1. (1) The purpose of this document is to provide guidance on new Air Traffic Flow Management (ATFM) regulations.

1.2 Applicability

  1. (1) This document applies to holders of Air Traffic Services (ATS) Operations Certificates issued in accordance with the Canadian Aviation Regulations (CARs) Part VIII.

1.3 Description of changes

  1. (1) Not applicable.

2.0 References and requirements

2.1 Reference documents

  1. (1) It is intended that the following reference materials be used in conjunction with this document:
    1. (a) Aeronautics Act (R.S.C., 1985, c. A-2)
    2. (b) Civil Air Navigation Services Commercialization Act (S.C. 1996, c. 20)
    3. (c) Part VIII, Subpart 1 of the Canadian Aviation Regulations (CARs) — Air Traffic Services
    4. (d) Standard 821 of the CARs — Air Traffic Flow Management

2.2 Cancelled documents

  1. (1) Not applicable.
  2. (2) By default, it is understood that the publication of a new issue of a document automatically renders any earlier issues of the same document null and void.

2.3 Definitions and abbreviations

  1. (1) The following definitions are used in this document:
    1. (a) Air Traffic Flow Management (ATFM): Actions that contribute to the safe, orderly and expeditious flow of air traffic by ensuring that air traffic control capacity is utilized to the maximum extent possible and that the traffic volume is compatible with that capacity.
    2. (b) Flow Control: Measures used to adjust the flow of traffic into a given airspace, along a given route, or operating at a given aerodrome, to ensure the most effective utilization of the airspace or aerodrome.
    3. (c) Metering: A flow control measure whereby a minimum interval is established between aircraft over a specific fix, into a defined airspace, or to a specific unit.
    4. (d) Operational Capacity: A dynamic, time-specific capacity value derived from strategic capacity, to be updated as required and used in pre-tactical and tactical ATFM.
    5. (e) Strategic Capacity: A measurement of the ability of the ATC unit to provide safe, orderly, and efficient service to aircraft during normal circumstances expressed as the number of aircraft entering a specified controlled airspace or operating at a specific aerodrome in a given period of time.
    6. (f) Traffic Management Initiative (TMI): Technique used to manage air traffic demand for an airspace, along a given route, or at an aerodrome, to ensure the most effective utilization of the available airspace or aerodrome capacity. It is a measure that is applied temporarily without changing the level of service of an ATC unit.
    7. Note: A TMI can be a short-term measure that is applied when circumstances limit capacity for a few hours, or it can be medium term when capacity is limited for a few weeks. In both cases, it is possible to predict when capacity will return to normal without changing the level of service.
  2. (2) The following abbreviations are used in this document:
    1. (a) ATC: Air Traffic Control
    2. (b) ATFM: Air Traffic Flow Management
    3. (c) ATS: Air Traffic Services
    4. (d) CDA: Canadian Domestic Airspace
    5. (e) CDM:Collaborative Decision Making
    6. (f) CYUL: Montréal Pierre-Elliot Trudeau International Airport
    7. (g) CYVR: Vancouver International Airport
    8. (h) CYYC: Calgary International Airport
    9. (i) CYYZ: Toronto Pearson International Airport
    10. (j) ICAO: International Civil Aviation Organization
    11. (k) TCCA: Transport Canada Civil Aviation
    12. (l) TMI: Traffic Management Initiative; and
    13. (m) VFR: Visual Flight Rules.

3.0 Background

  1. (1) During daily operations, the air traffic demand often exceeds the capacity. There may simply be too many aircraft, not enough ATS personnel, not enough runways, or there are weather impacts. At such times, implementation of traffic management measures is essential to maintain a safe, orderly and expeditious flow of air traffic through Canadian airspace and to and from Canadian aerodromes.
  2. (2) ATFM starts with planning and monitoring the demand, the capacity, and the constraints at aerodromes and in airspace. This initial phase enables stakeholders to collaboratively identify where imbalances exist or are likely to exist. It considers the planned use of airspace and aerodromes and the capacity of the air traffic control system to support safe, orderly and expeditious services.
  3. (3) In operations, ATFM enables stakeholders to share accurate and up-to-date information; therefore, informed decisions can be made to balance demand with capacity, improve traffic flow, and maintain system safety.
  4. (4) ATFM, including the application of Traffic Management Initiatives (TMIs) when needed, is a long-standing operational practice, including from before the transfer of the Canadian air navigation system to NAV CANADA in 1996 by the Civil Air Navigation Services Commercialization Act. To formally identify responsibilities and align with ICAO Annex 11, Transport Canada Civil Aviation (TCCA) has added regulations in Subpart 1, Part VIII of the Canadian Aviation Regulations (CARs). This regulation incorporates by reference a Standard 821 – Air Traffic Flow Management (hereinafter referred to as the ATFM Standard), to support ATFM. This means that the detailed provisions in the Standard are mandatory under the regulation.
  5. (5) The ATFM Standard details requirements for most areas of the Canadian Domestic Airspace (CDA), in addition to the long-standing procedures applicable for CYVR, CYYC, CYYZ and CYUL.
  6. (6) ATFM is most effective when there is communication and collaboration among stakeholders. The ATFM Standard imposes a requirement for Air Traffic Control (ATC) units to implement procedures for flow control of VFR traffic. TCCA recommends that, where flight training units operate, they actively engage with the relevant ATC units in the development of flow control procedures. Such engagement could include entering into agreements to ensure safe and equitable sharing of airspace and Air Traffic Control (ATC) capacity.

3.1 Capacity Management - Staffing

  1. (1) Staffing of ATC units is the responsibility of the ATS Operations Certificate holder. The number of required qualified individuals in an ATC unit is determined based on historical traffic demand, including normal and peak levels, but the standard requires that other factors be considered as well.
  2. (2) Daily staffing of ATC units should be monitored and adjusted, to the extent possible, when the traffic demand is expected to be higher than capacity. When it is not possible to increase ATC capacity (using procedures, infrastructure, staffing or some combination of these) to meet the demand, TMIs must be implemented.
  3. (3) The ATFM Standard details requirements for record keeping when TMIs are implemented. Along with enabling oversight and transparency, such records should be used by the ATS Operations Certificate holder when reviewing ATC staffing requirements.

3.2 Strategic Capacity

  1. (1) Strategic capacity is determined based on normal operations and can be thought of as a prediction of the flow of traffic that can be safely provided with ATC services; it can be based on annual traffic counts or in certain circumstances, broken down into shorter periods. In addition to considering normal operations, planned events or known circumstances that have an impact on operations are also considered when determining strategic capacity. For example, if an Aerodrome Operator is planning the closure of a runway for construction, the information would ideally be communicated to stakeholders in the weeks or months ahead of the project. This would enable the impacts on capacity to be assessed, and the strategic capacity to be updated. This would also facilitate Collaborative Decision Making (CDM) among affected stakeholders to agree on changes to planned operations and ATC capacity to minimize, to the extent possible, negative impacts on the efficiency of aircraft operations. It is the opinion of TCCA that such collaboration, initiated as far ahead as possible, will facilitate safety, efficiency and equitable access to ATC services.

3.3 Operational Capacity

  1. (1) Operational capacity is determined tactically based on how real time events affect the predicted operations; therefore, operational capacity is an adjustment to the strategic capacity. In most circumstances, the operational capacity will be lower than the strategic capacity due to events such as an unplanned runway closure, a thunderstorm, or an aircraft emergency, that impact the predicted operation. In other circumstances, the operational capacity can be higher than the strategic capacity. A higher-than-expected traffic demand could be managed by temporarily implementing procedures or increasing staff or infrastructure, until operations return to normal.

3.4 ATFM

  1. (1) ATFM manages predicted imbalances between traffic demand and operational capacity by using procedures that enable stakeholders to collaborate and determine how best to maintain a safe flow of air traffic. In the longer term, ATFM provides essential data and collaboration networks to identify and address persistent deficits in strategic capacity.
  2. (2) Because operational capacity is managed tactically and may require stakeholders to react, a dedicated traffic management function is required to coordinate between all stakeholders. The required training, knowledge, and procedures for individuals who perform this function are detailed in the ATFM Standard.

3.5 Flow Control

  1. (1) The ATFM Standard aligns, to the extent possible, with NAV CANADA’s existing practices for ATFM in Canada. There are, however, additional requirements related to keeping TMI records that will come into force on January 1st, 2028. These requirements were included in the interest of transparency and oversight.
  2. (2) Prior to the ATFM Standard being created, many ATC units where service is mostly provided to VFR aircraft had procedures in place for flow control of VFR traffic. In addition to the ATFM Standard requiring that such procedures must be developed and implemented, it also states that collaboration with stakeholders must take place. This is particularly important at aerodromes; therefore, TCCA recommends that consultation occur among local stakeholders regarding aerodrome operations to enable a coordinated effort to balance demand and capacity and develop strategies to ensure safe and efficient operations. Those strategies can vary and be implemented with short term trials or through formal agreements.

4.0 Information management

  1. (1) Not applicable

5.0 Document history

  1. (1) Not applicable

6.0 Contact us

For more information, please contact:
Chief, Flight Standards (AARTA)
E-mail: TC.FlightStandards-Normsvol.TC@tc.gc.ca

We invite suggestions for amendments to this document. Submit your comments to:
AART Documentation Services
E-mail : AARTDocServices-ServicesdocAART@tc.gc.ca

Original signed by

Jamie-Lee MacDermid,
Executive Director, Standards Branch,
Civil Aviation

AC 801-002 - Air Traffic Flow Management (ATFM) Procedures
(PDF, 308 KB)

Date modified: