Pilot Debrief

GADDIS MICHAEL EXEC 162 F near Plymouth, IN — 2017-09-16

Final reportCEN17LA365
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Date
2017-09-16
Location
Plymouth, IN, USA
Aircraft
GADDIS MICHAEL EXEC 162 F
Registration
N123XZ
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

A failure of the drive belt for reasons that could not be determined based on the available information.

NTSB narrative

As the helicopter approached the airport, the pilot reported that the helicopter's engine rpm increased, and the rotor rpm decayed. He conducted an autorotation to the field. An examination of the helicopter revealed that the helicopter's main rotor drive belt/cog belt lost teeth resulting in a failure of the belt to drive the main rotor blades. The drive belt had recently been installed, about 3.5 hours prior to the accident. The circumstances of the accident are consistent with improper tension of the cog belt resulting in a failure of the belt.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have conducted maintenance check before the flight.

NTSB coding

Evidence available

  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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