Pilot Debrief

BELL UH-1H near Santa Barbara, CA — 2010-06-24

Final reportWPR10TA318
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Date
2010-06-24
Location
Santa Barbara, CA, USA
Aircraft
BELL UH-1H
Registration
N205KS
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Hover

Probable cause

The failure of left tailboom upper attachment fitting as a result of fatigue.

NTSB narrative

The helicopter experienced a structural failure in one of the tailboom attach fittings while hovering near a cliff, about 200 feet above ground level (agl). The pilot heard a loud sound and felt the helicopter yaw slightly. He made a precautionary landing without incident. A postaccident examination of the helicopter revealed the left tailboom upper attachment fitting had fractured as a result of fatigue. The fatigue origin most likely emanated from fretting and/or corrosion pits at the fastener to fitting interface. There was no engineering data showing how the combination of the multiple STC modifications of the helicopter affected the helicopter's structural integrity.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Proper inspection and maintenance of tailboom fittings could have prevented failure.

NTSB coding

Evidence available

  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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