Question: is 40 minutes enough time for a layover in seattle?
Answer: Anyway, 40 minutes in SEA is safe if your inbound flight is on time (although there probably won't be time to dally), and AS runs a very good on-time operation in SEA in general. This is key. If you have to gate check on an RJ or prop, that can easily add 5-10 minutes before you can start walking to the next plane.