On February 21, 2004, at 1355 Pacific standard time, an experimental Gillespie Sport Copter Vortex gyrocopter, N96XV, impacted a dry riverbed following a loss of engine power, approximately 1 mile southeast of the Sutter County Airport, Yuba City, California. The pilot/builder was operating the gyrocopter under the provisions of 14 CFR Part 91. The gyrocopter sustained substantial damage; the private pilot sustained fatal injuries. Visual meteorological conditions prevailed, and no flight plan had been filed. The gyrocopter departed the Sutter County Airport at an unknown time for the local, personal flight. A witness to the accident reported that he was standing in his yard. He saw the gyrocopter fly overhead at 50 feet, with the engine sputtering. It then entered a steep descent and impacted a dry riverbed about 45 yards away. At the wreckage site, approximately 1/2 tank of fuel was present; there was no fire. The National Transportation Safety Board investigator-in-charge (IIC) reviewed excerpts of the pilot's logbook. The entries indicated that the pilot was signed off to solo on January 25, 2004. On February 8, the logbook entry stated, "First gyro solo! Test flight of vortex. 3 pattern loops." The pilot had accumulated approximately 11 hours of gyrocopter flight time prior to the accident flight. Inspectors from the Federal Aviation Administration examined the gyrocopter on February 24, 2004. The blades of the pusher propeller, made of carbon fiber and foam filled, were displaced from the gyrocopter and displayed cracks on the surfaces . The main rotor was bent downward and impacted the gear ring on the main drive shaft. The Rotax 582 engine contained oil and was rotated. One of the carburetors was displaced from the engine. Neither carburetor contained fuel. The fuel screens in each were examined; both were free of debris. The vacuum line to the pneumatic fuel pump was made of a collapsible, soft material, and was kinked at a 45-degree angle at an attachment fitting. The fuel pump was tied to the radiator hose. One spark plug was removed and was gray in color. The inspector further stated that this was the second test flight for the gyrocopter. The tachometer time indicated 12.2 hours. In the Rotax Aircraft Engines Installation Manual, page 15-1, it states that the vacuum line to the pneumatic fuel pump must be made of a stiff material. Sport Copter, the gyroplane kit manufacturer, supplies the clear, braided engine vacuum pump line. According to the manufacturer, the line was rigid enough for its intended purpose. The manufacturer did not report any other similar accidents. The Experimental Aircraft Association (EAA) was contacted regarding the vacuum fuel line. According to a technical specialist, it is common for homebuilders to use clear, nylon reinforced fuel lines. These lines are used due to their ease of installation and ability to withstand vibration. According to FAA Advisory Circular AC 20-27F, Certification and Operation of Amateur-Built Aircraft, "Amateur builders are free to develop their own designs or build from existing designs. We do not approve these designs and it would be impractical to develop design standards for the wide variety of design configurations, created by designers, kit manufacturers, and amateur builders."