Fatigue On The Part Of Mechanic Also A Contributing Factor
The NTSB said Tuesday it has determined that a loose locking nut in a rotor mechanism was the probable cause of an accident near Lake Mead, NV, that resulted in the fatal injury of all five people aboard a Eurocopter AS350-B2 helicopter, operated by Sundance Helicopters, Inc., on a sightseeing trip. The aircraft went down in mountainous terrain about 14 miles east of Las Vegas, NV.
At a meeting held Tuesday morning to present the findings of the 13-month investigation, the board said the locking nut worked loose from the rotor assembly, causing a loss of control of the aircraft, according to a report from the Associated Press. The board said that the mechanic, who had been called in to work early in the morning to perform maintenance on the helo, was fatigued and improperly installed the nut. The aircraft did pass its required inspections before the accident flight, the board said.
The board said mechanics and inspector should be required to use checklists to avoid such maintenance errors.
Those fatally injured in the accident included the pilot, a couple from Utica, KS, and a couple from India on their honeymoon.