Not at TSA but it is worth noting that when I was applying to regionals they were giving out sen #s up to 3 months before classs (senority reservation) And yes this was for senority not just longevity. I had a friend who did that and he jumped over people there to go straight to a line. As far as the Skywest cadet program you accrue longevity for vacation, sick time, bonuses, travel benefits, ect. but you are jr to everyone already here.