There appears to be a shallow pool. Just saw an old mil compadre in his new hire class (I was training for 70 F/O upgrade). Took three weeks from when we walked in his package to an interview call, two weeks for the job offer, and a month till a call for a class. He got called to fill a hole, after listing himself for short notice call with HR. If you are in a position to do that (unemployed or working where you don't need to give two weeks notice) it can get you into class sooner. In my new hire class, we had a guy get the call the day class started to fill a no-show. He came down from MSP and started class the next morning.
Classes are set up to meet anticipated requirements (currently to back fill 50 seat F/O slots opened up by 70 seat deliveries). The company doesn't publish a list of future class dates, because they won't bring you on property to just sit around. If a delivery slides, then the class date to fill that delivery slides.
Current 70 seat slots are all being filled by 50 F/Os bidding over, though it could go back to new hires depending on how the pilot group bids.
And the pool doesn't seem to be FIFO (first in, first out), they sometimes call based on an internal criteria we aren't privy to, so you may get called before or after someone else who was given an offer of employment before you. The key here is that the letter is an offer of employment. You aren't hired until you show up for class. So don't quit your day job based on the letter.
Good luck with the interview.
