thanks for the replies. I suppose he could have been doing a maintenance run. Interesting that he came from the south while depratures from OHare at the time were northerly. There is a facility at the old Wurtsmith AFB in Oscoda MI (north-eastern lower peninsula) which was the direction he was headed. Im not sure American would use the services there or even what they do exactly there. I would think any such problem would be provided for at OHare.
Could it have been training related?