Not at Delta.

We only have a seat lock when training is required. The new contract tweaked it a little, but basically it's tied to the type up course. Normal Initial course is 2 year lock ("category freeze"). Differences training is 9 months (767-300 to/from 767-400, or 330 to 350 - only for F/O to F/O or Captain to Captain). All others (e.g. F/O to Captain in the same equipment) is 12 months. Most changes are going to be a 2-year seat lock.

Mandatory displacements carry no seat lock. First Captain upgrade can break a seat lock, but the balance of any "old" lock is added to the "new" lock.

Also, new hires have a 2-year seat lock, but they can bid to new equipment after 1 year to a new base if they can't hold their current equipment in that base.

Keep in mind, these times are when it can be awarded. Training and converting can be as long as 150-330 days later, depending on the type of bid.