Three F-16s roared toward Fenway Park, flying wingtip to wingtip. Suddenly a fourth F-16, trailing behind the formation, caught up, flew under the three F-16s, then looped up and over the formation to take its rightful spot for a perfect V formation. The maneuver, performed during the Red Sox Opening Day game Tuesday, came just as the Boston Symphony Orchestra finished playing the national anthem. It elicited roaring applause and cheers from the full-capacity crowd, which clearly appreciated what it thought to be great showmanship. But as it turns out, the maneuver was improper and the Vermont Air National Guard...