NTSB Identification: ERA14FA396
14 CFR Part 91: General Aviation
Tuesday, August 19, 2014
Probable Cause Approval Date:
MCDONNELL DOUGLAS HELICOPTER 369E, registration:
Injuries: 2 Fatal.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The pilot and passenger were inspecting a span of high-tension powerlines for damage after a recent storm. Recorded data showed that the helicopter departed and proceeded along the left side of the span at an altitude roughly consistent with the height of the suspended wires. The helicopter’s last recorded position was about 400 ft laterally and about 25 ft below the point where it ultimately contacted and severed the uppermost wire of the span, which was about 150 ft above ground level. The severed wire was located on the right side of the span, whereas the helicopter was flying on the left. The helicopter’s ground track transitioned from left to right and back across the span near transmission towers earlier during the flight; however, there were no transmission towers located in the immediate vicinity of the accident site. Portions of the wreckage came to rest directly below the severed wire, and oriented along a debris path to the right of and along the helicopter’s previous direction of travel. Examination of the wreckage revealed no evidence of any mechanical malfunctions or failures before the helicopter contacted the wire.
The National Transportation Safety Board determines the probable cause(s) of this
An inadvertent collision with a utility wire for reasons that could not be determined from recorded data and examination of the helicopter and accident site.