A summer weekend runway alternation program at Pearson could provide residents with predictable relief during low-traffic periods on summer weekends when residents are more likely to be outside or have their windows open.
Benefiting neighbourhoods could see a marked reduction in air traffic over as many as 13 weekends, depending on operational and capacity requirements.
Proposed program
The proposed program is a Summer Weekend Runway Alternation Program that includes the east/west runways only.
The program would:
- Run from May to October (26 weekends) when residents are outdoors, or are more likely to open the windows
- Run from 6:30 am to 11:59 pm when the preferential runway hours start
- Publish a reliable schedule, with up to 98% certainty (based on historical wind information) as to which weekends residents can expect relief
Reasons for this proposal
During the technical analysis of the Summer Weekend Runway Alternation Program, we studied two operational concepts and measured them against the same criteria:
- Ability to adhere to a published schedule
- Maintain current landing/departing capacity requirements
- Reflect the values and guiding principles provided by our 2017 Residents' Reference Panel
The first runway alternation concept included all five runways: two north/south and three east/west.
The second runway alternation concept only included the three east/west runways.
Analysis determined that it wasn’t feasible to include north/south runways in the program because then we would not have been able to adhere to the schedule and maintain the necessary landing and departing capacity requirements.
How the program works
This program would benefit communities under the final approach and initial departure paths of the east/west runways. Residents living under the east/west downwind segments of the existing flight paths would not see respite from this program.
The graphics below show how this program would work. Depending on where you live, you would receive partial respite on up to 13 weekends over the summer.
Odd Weekends
Group A Partial Relief (southwest and northeast)
Westerly operations
Easterly operations
Even Weekends
Group B Partial Relief (southeast and northwest)
Westerly operations
Easterly operations
Because aircraft traffic would be redistributed evenly across communities to the east and west of the airport, some communities may see an incremental increase or decrease in operations overhead on the 13 weekends that are the non-respite weekends.
We call this a partial respite - not total respite - because during certain hours of the day, there are more arrivals scheduled than the runway configuration can support. For example: let’s say the arrival rate that can be supported is 44 arrivals an hour, but there is an hour with 48 arrivals.
We would need to offload these additional arrivals onto the runway being used for departures. The same is possible for departures that need to be offloaded onto an arrival runway. As such, the community with the partial relief may still experience occasional aircraft noise, but it will be far less than the aircraft noise experienced on a non-respite weekend.
The graphic below shows the estimated hours of day we may be able to use runway configurations as the airport traffic demand is projected over future years. Remember, the summer weekend runway alternation program relies on a land 1/depart 1 configuration.
The graphic below shows the traffic distribution (arrivals and departures) over the entire summer period (26 weekends), comparing actual traffic distribution from 2015 against modeled future traffic distribution.
The benefits and impacts per community
Over the course of the 26 weekends, the program would more evenly distribute the departures and arrivals across the runways. Remember this program would only benefit communities to the east and west of the airport under final approach/initial departure, not residents living under the downwind segment.
We’ve compared modeled future weekends to what your community would have typically experienced on a predominantly easterly or westerly weekend in 2015. The numbers in the diagrams are the percentage of flights.
Wondering what this means for your neighbourhood over a single weekend in the summer? Using the map below, determine which quadrant community you live in, and see the corresponding section below to learn more about how this program may benefit you.
Northwest communities
Some communities, such as yours, may see a potential percentage decrease in operations overhead over the course of the 26 summer weekends. Additionally, your community will also benefit from some weekends of respite.
Southeast communities
Some communities, such as yours, may see a potential percentage decrease in operations overhead over the course of the 26 summer weekends. Additionally, your community will also benefit from some weekends of respite.
Northeast communities
Some communities, such as yours, may see a potential increase in operations overhead over the course of the 26 summer weekends. However, given the lower traffic levels during summer weekends, we believe that this change will be only an incremental change over how traffic is currently experienced, and comes with the benefit of some weekends of respite.
Southwest communities
Some communities, such as yours, may see a potential increase in operations overhead over the course of the 26 summer weekends. However, given the lower traffic levels during summer weekends, we believe that this change will be only an incremental change over how traffic is currently experienced, and comes with the benefit of some weekends of respite.
Noise modelling
The noise modelling below was completed using industry standard software. The GTAA provided the traffic forecasts used.
The average noise images represent the average aircraft noise that would be experienced over an average weekend day between 6:30 am and 11:59 pm. Average noise is a standard way that airports look at the noise impact that the aircraft operations are having on local communities; but it is not easy for individuals to relate to average noise as we hear individual noise events not average noise.
The number of noise events images provide coloured contours based on the number of noise events over 70 dB (e.g. vacuum cleaner, hair dryer, noisy restaurant) within the 17.5 hour operational day.
Odd weekends – southwest and northeast noise respite
Westerly operations - average aircraft noise over 17.5 hrs
Westerly operations – number of noise events above 70 dB
Easterly operations – average aircraft noise over 17.5 hrs
Easterly operations – number of noise events above 70 dB
Even weekends – southeast and northwest noise respite
Westerly operations – average aircraft noise over 17.5 hrs
Westerly operations – number of noise events above 70 dB
Easterly operations – average aircraft noise over 17.5 hrs
Easterly operations – number of noise events above 70 dB
Why the north/south runways are not included in the proposed program
We assembled a Residents’ Reference Panel (RRP) to provide us with community views on the next phase of our growth. The 36 members of the RRP were selected at random, but in such a way that they broadly represent the demographics of the Greater Toronto Area (GTA) – in terms of gender, age, home ownership, and other criteria. They were also selected to ensure strong representation by residents of neighbourhoods that are strongly impacted by aircraft noise.
As part of their final report, the RRP provided us with a set of values and guiding principles to ensure that the community’s voice would be reflected in our decisions.
The Panel recommended that we only pursue a runway alternation program if the respite afforded to communities is meaningful and predictable. This means that the program must be predictable enough that residents can plan around it, and the relief periods must be long enough and the program viable long term so that it is meaningful.
The technical analysis demonstrated that any alternation program that would involve the north/south runways could not meet these guidelines because of the number of days when we would be required to use non-scheduled runways. This is because:
- Any alternation program involving the north/south runways would have to be achieved in a dedicated-mode, land 1/depart 1 runway configuration. The north/south runways are only permitted to operate in this configuration because of their proximity to each other.
Note: A dedicated-mode, land 1/depart 1 configuration is when two runways are used simultaneously, one exclusively for arrivals and the other exclusively for departures. At times, to accommodate traffic, the dedicated departure runway can also be used for arrivals when there are gaps in departure traffic and vice versa. We call these offloads.
- While the north/south runways can accommodate offloads, these runways cannot accommodate the dual or triple operations which are needed for a small number of weekend hours.
By comparison, our three east/west runways can be used in a dual or triple configuration, making a program with just the east/west runways more viable long term.
Please note, an east/west summer weekend runway alternation program does not mean that residents under the north/south runways will not experience aircraft overhead. We will continue to use these runways as necessary to support our operations, such as in instances due to wind, weather or runway availability.
Conclusion and next steps
Testing the Summer Weekend Runway Alternation Program will validate the technical analysis predictions and include an opportunity for the community to confirm if the programs' respite is meaningful and predictable.
Want a refresher about the different runway configurations and modes? Visit our glossary.