Pilot Debrief

BELL-WATSON 47 G near North Little Rock, AR — 2015-01-29

Final reportCEN15LA131
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Date
2015-01-29
Location
North Little Rock, AR, USA
Airport
ORK
Aircraft
BELL-WATSON 47 G
Registration
N43762
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Landing

Probable cause

The flight instructor’s failure to maintain adequate rotor rpm during the practice touchdown autorotation, which resulted in a subsequent loss of helicopter control and impact with terrain.

NTSB narrative

The flight instructor reported that he was demonstrating a power-off touchdown autorotation to a large, open paved ramp area. He added that, while flaring the helicopter for touchdown, the rotor "seemed to run have out of energy" but that the rotor tachometer indications did not indicate a reduction in rotor rpm. The tail skid subsequently contacted the asphalt, and the helicopter bounced into a nose-low attitude. The main rotor blades then struck the pavement and the tailboom, which resulted in the complete separation of the tail rotor assembly, the partial separation of both main rotor blades, and damage to the skid gear. The helicopter rotated right about 180 degrees from the landing direction and came to rest upright. A postaccident examination of the helicopter, including the dual tachometer indicator and the rotor tachometer indicator, found no preaccident anomalies that would have precluded normal operation. The accident sequence is consistent with an inadvertent loss of rotor rpm and subsequent loss of helicopter control.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Flight instructor allowed rotor RPM to get too low during landing approach.

NTSB coding

Evidence available

  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

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