Hap Harper’s radio career began in 1957 when he gave flying lessons to the late, legendary disc jockey Don Sherwood. Sherwood asked Harper to go aloft and give weather reports from the air during his show. “Hap would say it was cloudy or foggy, but everyone already knew what the weather was anyway,” his wife, Jan, told the Chronicle. “But then one day he looked out the window and saw a traffic accident, and he warned people to avoid it, and Sherwood said, ‘That’s it, that’s your new career.’ ” He became a regular on Sherwood’s show. And he became widely known for telling jokes, particularly bad jokes, to lighten thte bad news about traffic, the Chronicle pointed out in his obit today. He died of heart failure Wednesday in Jackson, Calif., at age 81.