Bell 407 N31PB accident near Delray Beach, Florida

Probable cause

The pilot’s improper response to a simulated engine failure and the instructor’s delayed and improper remedial action.

NTSB analysis

While in cruise flight during the law enforcement aerial surveillance and evaluation flight, the instructor induced a simulated engine failure. The pilot being evaluated rolled the throttle from the idle position back to the flight position instead of lowering the collective to maintain rotor rpm. The instructor then took control of the helicopter, but he did not lower the collective either, and the main rotor rpm subsequently decayed to well below the lower limit of the normal operating range. The low-rotor condition resulted in a loss of helicopter control and glide capability and a subsequent hard landing in trees. Examination of the flight department's training program revealed that the conditions and standards for the performance of a simulated engine failure were not outlined as a separate task within the manual and that the manual did not provide information regarding entry altitudes, callouts, recovery altitudes and procedures, or maneuver termination protocols. The instructor reported no mechanical deficiencies with the helicopter that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for ERA12TA251 for the full record.