January 30, 2020

Getting smart about turbulence: Revising separation criteria at Canada’s major airports

As global air travel continues to grow, the demand for airport capacity increases with it. In anticipation of this future growth, NAV CANADA is leading several initiatives that will increase the number of airplanes that can land and depart each hour. We’re updating the separation standards between aircraft to optimize runway use at capacity constrained airports.


Aircraft create turbulence in their wake. The common belief is that the bigger the aircraft, the bigger its wake. Aircraft have traditionally been categorized by weight – light, medium, heavy and super. To avoid encounters with the turbulence that forms behind aircraft, separation minima were established decades ago to ensure the safety of aircraft of any size.

Experts now have an improved understanding of wake turbulence thanks to new advances in measurement techniques and the availability of surveillance data. With the types of aircraft in the skies now vastly different than decades ago, there is great opportunity to update these separation standards while maintaining safety.


The International Civil Aviation Organization (ICAO) is establishing new international wake separation standards, moving from four categories to seven groups. Rather than categorizing aircraft by weight, Enhanced Wake Separation is based on the wake characteristics of the lead aircraft and the resistance to wake of the following aircraft.

The Enhanced Wake Separation groups depend primarily on the aircraft’s maximum certified take-off weight, wing characteristics and speed.

It’s important to note that the enhanced wake separation standards were developed to be as safe as, or safer than the legacy separation standards. While this new recategorization does introduce smaller separation standards in some cases, it also increases separation for the smallest, most vulnerable aircraft.

NAV CANADA is the first ICAO member to implement these new wake separation standards, rolling them out at Toronto Pearson in May 2019.

Enhanced wake turbulance separation categories


This greater level of precision gives more flexibility to air traffic controllers to safely reduce the separation between certain aircraft, depending on the fleet mix. Controllers can sequence aircraft in a way that minimizes spacing to maximize runway use.

These enhanced separation standards will increase the arrival rate at Canada’s major airports by as many as three aircraft per hour.  At Canada’s busiest aerodromes where air traffic demand continues to grow, the enhanced separation standards are a valuable solution to optimize airport capacity.

Benefits are already being realized at Toronto Pearson where Enhanced Wake Turbulence Separation was deployed this past spring. This means aircraft flying to Pearson are spending less time waiting to land and are saving on fuel.

NAV CANADA plans to integrate these new wake separation standards into each of Canada’s major airports – one way we’re helping to enable growth and improve airport efficiency.

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It would be more informative and useful to provide the aircraft types and separation tables for the new categories. Is this available somewhere else?

What is the impact on noise mitigation for those living under the flight paths? Am assuming a comprehensive study was done prior to implementation.

Thank you for valuable information, I have been investigating on TBO, 4DT both Eurocontrol and FAA, that include weather effect, these technologies will lead more efficent and more acutual flight operations in the near future, Does NAV Canada plan to try these technologies?


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