NTSB Identification: SEA96LA144.
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Accident occurred Saturday, July 06, 1996 in MCMINNVILLE, OR
Probable Cause Approval Date: 08/21/1997
Aircraft: Hughes 369D, registration: N5110Y
Injuries: 2 Minor.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The engine fuel governor had been replaced since the previous flight. About 4 minutes after takeoff, while maneuvering at 400 to 500 feet above ground level, the helicopter's Engine Power Out (EPO) warning light and horn activated. The pilot reduced collective and entered an autorotation, but had to turn downwind to clear trees. The engine N2 (power turbine) RPM was stabilized at 88 to 90 percent during the descent, as compared to a normal range of 102 to 103 percent. The helicopter touched down in a soft field at 20 to 25 MPH forward speed, slid about 30 feet, and rolled over. On-site investigators found the adjustable governor lever control rod disconnected from the governor control lever, which a McDonnell Douglas investigator stated would result in loss of automatic governing of engine RPM. The nut and washer for securing the adjustable control rod to the governor control lever were found in the bottom of the engine compartment, but the cotter pin specified for safetying the nut and washer was not located. The aircraft operating handbook directed pilots to check the fuel control and N2 governor linkages during preflight inspection.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: improper maintenance (replacement) and inspection of the engine fuel governor by company maintenance personnel, the pilot's inadequate preflight inspection, and a subsequent disconnect of the adjustable governor lever control rod, which disabled the engine speed governor and resulted in a partial loss of engine power. Factors relating to the accident were: trees and soft terrain in the emergency landing area, and a tailwind during the forced landing touchdown. Full narrative available
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