SOMEWHERE OVER THE POTOMAC RIVER – A sharply painted hunter green MV-22 Osprey taxies up near a hangar at the sprawling Marine Corps Base Quantico in central coastal Virginia. It has been pouring down rain and the sky is a gray soup of fog. Yet in the time it takes to walk 100 yards to the awaiting hybrid aircraft, the slick, saturated tarmac beneath the massive idling propellers has become bone dry. It’s the first indication of the massive amounts of power employed by the Osprey – part helicopter, part airplane – that the passengers on this particular flight are...