irishguy28

But will the "tier miles" actually count for anything for you in Skymiles? Unless you can use them to attain status, then that is just as much putting them into a "black hole".

However, the issue of a "black hole" in Aegean only occurs when you are requalifying for Gold, i.e. once you already have had Gold for almost a year. As it sounds like you are still only Silver, then the "black hole" issue cannot happen for you now, on this upcoming AC trip.

If you buy 500 Tier Miles, the date they hit the account - which should be the day on which you buy them - is the day you exceed the Gold threshold, and your status is increased to Gold, and your anniversary/membership year switches to that date. [Let's say its 15 February]

Therefore, your Air Canada flight will most definitely earn both Award Miles and Tier Miles, and those Tier Miles will be the first miles you add to your account in your request to get to 12k Tier miles [with A3 segments]/24k miles [without A3 segments] by 15 February 2019.

the issue of the "black hole" can only arise for you later in 2018, or in early 2019. Once you have exceeded either of the Tier Miles thresholds listed above, you will have "retained Gold" for a second consecutive year, which runs from 15 February 2019 to 15 February 2020. As such, once you have already retained Gold, it is indeed true that any further Tier Miles added to your account after that date, but prior to the commencement of the second Gold year, would have no effect (and won't even be mentioned in your account. Your account will merely show a statement saying "Gold retained to 15 February 2020" or something, and won't show you your Tier Mile target/balance until that second year commences on 15 February 2018)