The Air Force charged an F-15 pilot involved in shooting down two U.S. helicopters over Iraq last April with negligent homicide. Also charged, but with lesser crimes: five people who were aboard the AWACS radar plane that oversaw the action. The incident, one of the military's deadliest friendly fire tragedies, took the lives of 26 people. Lieut. Colonel Randy W. May could serve 26 years in prison if found guilty. No word yet about the fate of a second pilot, whom the Air Force hasn't identified.