I was stationed at Selfridge from 00-04 so just because "something" might happend due to 911's annv. is no reason for them to take up in the air. They are most likey doing night qualifications. I would spend many hours out at sea doing Helo op's, the reserve pilots would come to the ship and there soul purpose was to do touch and go's during day time and night time, sometimes well past 11pm, and they need so many certain hours of night landings for certain quals.
Remember Selfirdige is a Joint Task Force base home to alllll the branches of military, all the C-130's could be part of a squadron doing Annual training, taking forces up to Alpena where there is a HUGEEEEE simiulated city where they paint ball at. The last time I was up there we booked it late 02 and I didnt go until late 03, we did security force with FBI and Homeland security guys, fucking blast. The place has a sewer system, buildings, abadoned cars your basic urban war zone. But anyways we took 5 C-130's up there.