Overview
On August 14, 2012, at approximately 0910 central daylight time, a Bell 47G-2 helicopter, registration N444EH, sustained substantial damage during an autorotation landing after a loss of engine power near Flandreau, South Dakota. The pilot and passenger were not injured. The helicopter was operated as a personal flight under 14 Code of Federal Regulations Part 91 by private individuals. Visual meteorological conditions prevailed, and no flight plan was filed.
Flight History
The flight originated from Flandreau Municipal Airport (4P3) at about 0815, with the intended destination being the pilot's farm near Colman, South Dakota. The pilot reported that after conducting three approaches to the runway at 4P3, he departed for his farm. During cruise flight, approximately 4 miles from the farm, the helicopter experienced a loss of engine power. The pilot initiated an autorotation, but the only available landing area was a pasture, which resulted in a tailwind approach and landing. The landing was described as a “little rough,” causing the helicopter to bounce and roll onto its left side.
Damage and Injuries
The tail boom, main rotor blades, tail rotor blades, and fuselage were damaged during the autorotation landing. The helicopter was substantially damaged, but neither the pilot nor the passenger reported any injuries.
Postaccident Examination
A Federal Aviation Administration (FAA) inspector conducted an examination of the helicopter. The throttle system was found to not operate properly. The hand grip on the collective throttle control was loose, and movement of the hand grip did not fully translate into movement of the throttle linkage. The throttle cable was disconnected at both ends for further inspection, revealing that the cable was not free to move within the conduit. The conduit did not appear to be deformed or damaged in a way that would have prevented cable movement.
Maintenance Records
A review of maintenance records showed that the most recent annual inspection was completed on March 12, 2012, at a total airframe time of 15,659.1 hours. The engine had accumulated 549.0 hours since overhaul at the time of that inspection. The records included an entry dated May 8, 2012, stating: “New throttle conduit and cable installed. Needs Test.”
The mechanic who performed the throttle system maintenance stated that he had replaced the conduit but used the same cable assembly. The conduit was in new packaging from the manufacturer, but no serviceable tag was present. Regarding the “Needs Test” notation, the mechanic said that the owner had hover taxied the helicopter onto a trailer before it was transported from Kansas to South Dakota. The pilot informed the mechanic that the throttle system performed normally at that time.