20060405010219I

(-23) On April 5, 2006, approximately 8:30 a.m. at Wrangler Field (an abandoned flight training airport 70 miles west of forth worth, Texas), Bell's TR918 risk reduction prototype (rrp) technology demonstrator, was performing a deceleration maneuver at 300' AGL. Approximately ten minutes into the flight as the aircraft was decelerating below 30 KTS the aircraft lost power, descended slightly with nose and wings level, then pitched forward and crashed straight ahead in a ditch just beyond the ramp area of the airport. The aircraft was in "auto hover mode" under external pilot control. "Auto hover mode" allows the pilot to control aircraft speed with cyclic control with all other flight control functions performed the the flight control computer (fcc). Telemetry and video shows the aircraft under complete command and control except for the lack of lift. The aircraft pitched forward as it lost lift due to the difference in the aircraft's center of gravity and the center of lift. No control input, automatic or manual, was sent to the elevator control, and the elevator was performing normally until impact. Initial telemetry indicates the fcc was asking for more fuel to maintain its programmed altitude. The aircraft had 90 gallons of fuel on board with the aircraft at about 2,600 lbs gross weight, about 300 lbs short of its max gross weight. There was no post-crash fire. All notifications required per the faa's imposed operating limitations were followed including NTSB notification. The local NTSB office is interested in the outcome but are not involved in the investigation. It appears that Bell was operating within the operating limitations of it's experimental research and development airworthiness certificate issued on December 1, 2005, and in accordance with its flight teest program. The aircraft was removed from the site and brought to Bell's fort worth facility for continued investigation. Pratt & whitney was on-site and will be involved in the investigation. To date, the fuel has checked clean and the fuel filters were not clogged. No other blockage has been detected yet in other fuel supply components. The engine will have to be removed from the airframe with additional disassembly and testing of components to determine the cause of the power loss. All electrical wiring related to fuel control, passed at 100% continuity. This flight was the 9th flight representing 17.5 airframe hours, 19.9 engine hours, and 5.4 flight hours. Bell will build another aircraft and plans to continue this program. The wreckage and a video of the crash was viewed yesterday by representatives of the rotorcraft directorate. The video collaborates the information provided to the FAA. The audio portion indicates some chatter or interference on their VHF com frequency of 123.2 mhz, and may have been from a team of geological personnel in the surrounding area doing seismic surveys. Some of the seismic personnel were just outside the flight control area taking pictures of the aircraft. Bell is investigating the "thumper" devices used by the seismic team as is continuing to monitor all command and control frequencies.