So really you pay for the plane in a way? Alright, how timed are these missions and how much do the planes cost? Also, can the APD do anything in terms of intervening with these planes?
You want to delete the MP Mission file, and also, try joining another server, play a little, than hop on Asylum. If that doesn't work, sometimes you just have to wait a little for the server to sort itself out to allow you to join.