The pilot of a Eurocopter MBB BK117 C2, presumably confused by multiple cockpit warnings of engine trouble, shut down the unaffected engine and briefly flew on power from the failing engine before the helicopter crashed in a farming area, killing all four occupants, according to the U.S. National Transportation Safety Board (NTSB).
The NTSB said, in its final report on the Sept. 8, 2017, crash of the emergency medical services helicopter near Hertford, North Carolina, U.S., that the probable cause was the failure of the rear bearing in the No. 2 engine.
The bearing failure was followed by “multiple and likely unexpected and confusing cockpit indications resulting in the pilot’s improper diagnosis and subsequent erroneous shutdown of the No. 1 engine and … the resulting degraded performance of the No. 2 engine, until it ultimately lost power,” said the report, issued in January. “The complete loss of engine power likely occurred at an altitude and/or airspeed …
