Cesar Ceja's mother won't let him drive, but she'll let him fly. In fact, his mother says airplanes are one of the best things to happen to her almost 16-year-old. Three months ago, Ceja started coming to Young Eagles rallies, recommended by a friend of a friend. The group offers free flights for children 8 to 17 at Hayward Executive Airport. Experienced pilots, who hang around the small airport's hangars like chatty neighbors on a garage sale weekend, take up one or two passengers at a time. After one ride, Ceja was hooked. "I always wanted to be a pilot,"...