The company runs 4 vacancies per year where you can get any status your seniority can hold. Posted 7 months prior, awards posted 5 months prior, with effective dates within 3 months of the vacancy date. For example, the June vacancy posts in December, with February awards, and effective dates between April-June bid months. You can be awarded a status but get withheld from that status for up to a year (but get paid at that rate) from your effective date. Then in subsequent vacancies, you get released from your current status to your entitled status. So if there’s people withheld from X status, it won’t go to new hires.

The union runs mutual base exchanges each month for identical equipment statuses. You can’t switch equipment, only bases. It can be a bit of a gamble, if you get awarded a base swap in the vacancy, you can’t participate in the mutual base exchanges that could get you there earlier.

Probably missing some details but that’s the jist.