It lined itself up with his jet.

Fravor and his weapon systems officer started a clockwise turn and went down for a closer look; the other aircraft, flown by Alex Dietrich, stayed in high cover to watch both. About 90 degrees into the descent the object suddenly shifted its long axis, aligned it with Fravor’s jet and began to climb in a clockwise turn of its own. They continued down another 270 degrees, then went nose low toward where it would be: Fravor at about 15,000 feet, the object at about 12,000, about half a mile away and just left of the nose.