USAF Plane Overhead

Returning from Newburyport approaching the the last plaza on the Mass Pike before our exit, about 30 miles from home, we saw a series of these planes overhead (5-6 of them), obviously heading for landing at  Westover Air Reserve Base nearby. As we stopped in the parking lot, this was the last one, directly overhead--not a wonderful shot, but it will have to do. It is probably a version of the C-130 Hercules.

I previous identified it as a C-5 Galaxy--a serious mistake, since that in fact is a jet.  My regular email commentator was good enough to correct me.