Reddit user u/ywgflyer contends for CYYZ, Toronto International Airport,

23 is the "good" runway. The 24s are garbage in a crosswind because of the localized wind effect that all the hotels (and the terminal) have. I've never had a windshear problem on 23, but I've gone around several times on 24R with a crosswind from the right.

  1. I never visited CYYZ. But I just roamed CYYZ on Google Maps. I see many short hotels, maximum 7 floors? I see no tall edifices in or near CYYZ, except the two? ATC towers?

  2. But let's hypothesize that buildings near airport create these localized wind effects. How can these buildings erect in first place? Won't airport's lawyers try to stop these edifices being erected on grounds of safety? But I don't know aviation, land, or planning law.


1 Answer 1


Buildings near or on an airport are generally only restricted in height for obstacle clearance purposes. I've never heard of a wind related planning limitation that would apply at Pearson (although there may indeed be other airports with building restrictions of some kind due to some kind of unusual wind effects).

The buildings on the north side of 24L's threshold end at Pearson can certainly produce a fair about of "burble" below 300 ft that would bounce light aircraft around pretty good on a day with strong winds. They don't have to be all that tall; the area and complexity of the structures will produce plenty of turbulent flow in the surface boundary layer.

Anticipating this is a basic part of airmanship. Usually it's having an awareness of wind shadows caused by trees and hangars at small airports, but situations like Pearson with all the hotels and big hangars on the windward side of the threshold take it to another level. If I was landing there on a strong wind day on that runway and saw all the structures, I'd approach high and land farther down the runway to try to avoid the burble; same thing you do to avoid wake turbulence from a heavy that landed ahead of you.

If someone in an aircraft that only needs 1500 ft to land insists on landing on the threshold of a 9000 ft runway in spite of the turbulence generators to the right, they haven't been trained very well.

At the other extreme, if you were flying a Paramotor, you'd have to give the same consideration to small trees and houses on the upwind side of your landing area. It's all the same pretty much, just different in scale.


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