Quote:
Originally Posted by casper
I get that all the time on the flight from Victoria into Vancouver. From an air traffic control perspective, that has to be one of the easiest flight to manage.
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When any airport implements a ground delay program (GDP) or ground stop (GS), it is done so by a certain method that involves tiers.
A tier refers to the scope of a GDP/GS.
In the case of YVR,
First step is usually kept within the Vancouver flight information region (FIR), which is basically the province of BC (see map link below), meaning it only affects aircraft departing airports within BC. Hence why flights in/out of YYJ are
always affected by the YVR delays.
When it goes up to 1st tier, it refers to the first step above, plus all those enroute centers immediately adjacent to the one where a GDP or a constraint is in place. For example, for YVR, a 1st tier GDP would involve CZV (Vancouver FIR), but also Seattle ARTCC and Edmonton FIR. So aircraft departing from any one of those FIR's or ARTCC's would be caught in that ground delay and not be allowed to depart until their assigned controlled departure time.
A 2nd tier GDP would extend a bit further. Ex it might include flights departing Winnipeg FIR and Salt Lake City and Oakland ARTCC's as well.
So that's how it's done. Long haul flights coming from outside Canada or the US aren't affected by Canadian or US GDPs.
Here is a FAA map of Canadian FIR's and US ARTCC's. Click on "tier info".
https://www.fly.faa.gov/ois/?legacy=true
If you click on any US ARTCC, you will see the tiers associated with airports in that region. For example, if you click on Seattle ARTCC (ZSE), you can see that the first step involves just Seattle ARTCC. Tier 1 includes Salk Lake (ZLC) and Oakland (ZOA) ARTCC's, but also CYVR, CYYC and CYEG. Tier 2 involves first step + tier 1 + Los Angeles/Denver/Minneapolis ARTCC's as well. So that's how it's done. The worse the GDP/GS is, it usually means a higher tier is involved. When the shit really hits the fan (accident at an airport, or airport closure for any reason), a full on continental GDP or GS can be implemented. I've seen that before as well.
Canada does the same thing.