The National Transportation Safety board has released a final report on the helicopter crash that happened in the shallow waters of Crows Pond in Chatham back in June of 2016.
The NTSB says a review of maintenance records revealed that, due to a logbook entry error, the helicopter had been operated about 52 hours beyond the mandatory airframe overhaul time limit; the helicopter manufacturer’s maintenance manual required that the entire airframe be overhauled every 2,200 hours.
Examination of the engine revealed multiple issues consistent with an engine overspeed, which resulted in sufficient damage to lose total power to the engine.
At the time of the accident, witnesses said the helicopter was flying low over the shoreline and appeared to be in mechanical distress.
The NTSB concluded inadequate maintenance of the lower forward clutch actuator bearing for a prolonged period of time, which resulted in a bearing failure, and an erroneous maintenance entry leading to the helicopter being operated beyond its mandatory overhaul time were the probable causes of the accident.