Not sure if this has been discussed before, I couldnt' find anything so Mods if it has please delete.
When we come in on the C-5 from an international base like ETAR, we are not allowed to deplane nor open any doors except to deplane the scanner until CBP has cleared both the crew and the airplane. Yet when I was on a flight from FRA-ATL a while back, we deplaned as normal and made our way to Customs. Does the airplane and/or cargo itself have to be cleared/checked before anything happens? Do pax not see it or do they deplane before Customs boards?