Four pilots at Vance Air Force Base in Enid are under investigation to determine if they flew too low over Kennick Stadium in Iowa before the Hawkeyes played Ohio State back in November. "The gentlemen involved are instructor pilots and part of this was a training mission," said 1st Lt. Katherine Roling. Although the fly over was authorized, pilots with the Air Force are required to fly at least 1,000 feet above congested areas such as a sports stadium. Nearly two weeks after the flyover, the Air Force is still trying to determine exactly how low the pilots flew. Since...