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Aviation Accident

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NTSB Identification: WPR10LA046
14 CFR Part 91: General Aviation
Accident occurred Wednesday, November 04, 2009 in Globe, AZ
Probable Cause Approval Date: 09/13/2012
Aircraft: EUROCOPTER AS350BA, registration: N617LH
Injuries: 2 Serious.

NTSB investigators may have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

During a night vision goggle (NVG) training flight, the flight instructor initiated a simulated hydraulic failure on the downwind leg for landing. The flight instructor stated that during this maneuver, the pilot receiving instruction did not properly adjust the trim and did not maintain sufficient air speed. The helicopter slowed to about 20 knots, which was half the speed the flight instructor expected. When the flight instructor heard what he believed to be the low rotor horn and heard the pilot exclaim “uh-oh,” the flight instructor tried to regain control of the helicopter; however, the helicopter impacted the ground hard. Interviews with the pilot and instructor established that both were manipulating the controls after the initial loss of control and that no positive exchange of control had occurred. The pilot reported that the last time he had performed a simulated hydraulic failure was almost 1 year before the accident and that he had never performed such a procedure or had one demonstrated while operating with NVGs. The pilot and instructor reported no in-flight abnormalities with the helicopter before the initiation of the simulated hydraulic failure, and postaccident examination of the hydraulic system components revealed no abnormalities that would have precluded normal operation.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
  • The pilot receiving instruction’s failure to maintain adequate airspeed or control of the helicopter during a simulated hydraulic failure maneuver, which resulted in a hard landing. Contributing to the accident was the flight instructor’s delayed remedial actions and the lack of a positive exchange of control.