HISTORY OF FLIGHT On March 14, 1998, about 1343 hours Pacific standard time, a Gough-Herrman Christen Eagle II, N331GH, was destroyed after colliding with water at Lake Berryessa, California. Both the pilot owner and the pilot rated passenger received fatal injuries. Visual meteorological conditions prevailed for the personal flight, and no flight plan was filed. The flight originated at Vacaville, California, on the day of the accident. A witness reported seeing the aircraft flying about 1,000 feet or less over the lake, roll inverted for about 5 or 6 seconds and then pitch downward, rotate 90 degrees, and impact the water in a near vertical attitude. Other witnesses observed the aircraft during it's vertical descent. PERSONNEL INFORMATION First Pilot: The 20,200-hour airline pilot was the owner/operator and one of the builders of the aircraft. He was in the rear cockpit of the dual control aircraft. Second Pilot: The 14,300-hour airline pilot/passenger was located in the front cockpit. AIRCRAFT INFORMATION The experimental homebuilt aircraft was certificated in 1980. The builders were listed as Gough/Herrman, and the current owner/operator as Herrman. At the time of the accident, the aircraft had accumulated about 922.3 total flight hours. According to the designer/kit manufacturer's representative, the aircraft gross weight in normal operation, pilot plus passenger, is 1,600 pounds. In aerobatic operation, pilot plus passenger is 1,520 pounds. The estimated weight of the aircraft at the time of the accident was 1,516 pounds. The allowable center of gravity (CG) range at that weight in the aerobatic operation is 98.7 to 99.5 inches. The postaccident CG location was estimated at 98.5 inches, or 23.75 percent of the mean aerodynamic chord (MAC). WRECKAGE AND IMPACT INFORMATION The wreckage was recovered from Lake Berryessa 9 days after it impacted the lake. On March 26, 1998, the Safety Board and Textron Lycoming conducted a postaccident examination of the airframe and the engine. Control continuity was established and examined at attachment points and points of failure. All major components of the airframe, engine, and propeller were recovered and examined. TESTS AND RESEARCH INFORMATION During the postaccident examination of the airframe the left aileron bellcrank assembly was removed and sent to the Safety Board Materials Laboratory for examination of fracture surfaces. The fractures were attributed to overstress separation. A copy of the report is attached. ADDITIONAL INFORMATION The wreckage was released to the insurance company representative On August 25, 1998.