New hires can submit an LOR, but they carry little weight from what I have experienced. I have heard that pilots will only be able to submit one letter a year, but I don't know that that is the official policy now. I think a letter from an AWA PILOT is really necessary-unless your contact is high up in the airline. Good luck.
I hope we keep hiring every month as we have been since last July- we need many more people now!