On December 26, 2004, about 1430 Pacific standard time, an unregistered, Top Dog Trike ultralight airplane, collided with power lines near Torrey Pines, California. The owner/noncertificated pilot was operating the airplane under the provisions of 14 CFR Part 91. The pilot and one passenger were not injured; the airplane sustained substantial damage. The personal local flight departed from nearby private property, near Rancho Bernardo, California, about 1300. Visual meteorological conditions prevailed, and a flight plan had not been filed. In a telephone interview with the National Transportation Safety Board investigator, the pilot reported flying east along Penasquitos Canyon, about 150 feet above ground level. He said he did not see the high tension power lines or the power line towers ahead of him. The kingpin above the wing struck the lower power line, resulting in a loss of airspeed and altitude. The pilot did not attempt to recover to level flight by adding power, but maneuvered for a forced landing. During touchdown, the nose gear impacted soft terrain, and the airplane sustained damage to the wing and undercarriage structure. The pilot reported no preimpact mechanical malfunctions or failures with the airplane. The airplane's construction is a hang-glider type configuration with a tricycle undercarriage. The engine produces 50 horsepower and the airplane is equipped with two seats. According to the kit manufacturer's web site, the airplane's empty weight is 350 pounds. The owner/pilot did not have a flight training exemption to 14 CFR Part 103.