On January 26, 2000, at 1535 hours Pacific standard time, a Grumman American AG5B, N228ER, porpoised on landing and subsequently broke off the nose wheel at the Oakland, California, airport. The private pilot, the owner and operator of the aircraft, was not injured. The airplane sustained substantial damage. The purpose of the local area personal flight was to practice touch-and-go landings. The airplane departed from Hayward, California, approximately 1500, and was destined for Oakland when the accident occurred. Visual meteorological conditions prevailed at the time of the accident. The Federal Aviation Administration notified the Safety Board of the accident on March 27, 2000. The pilot stated that once he touched down on runway 27L, the airplane began bouncing. He said the bouncing got worse, and finally the nose pitched down and the nose wheel hit the runway, which broke off the nose gear strut.