Pilot Debrief

HILLER UH-12B near Rio Vista, TX — 2012-09-19

Final reportCEN12LA650
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Date
2012-09-19
Location
Rio Vista, TX, USA
Aircraft
HILLER UH-12B
Registration
N94735
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Maneuvering

Probable cause

The catastrophic failure and disintegration of the No. 6 engine piston, which resulted in a total loss of engine power.

NTSB narrative

The pilot reported that he was on a survey flight when the helicopter engine suddenly stopped; he elected to autorotate to a field. The area he landed in had high vegetation, which “grabbed” the helicopter skids and the helicopter impacted the ground hard. Examination of the helicopter revealed that the main rotor impacted the tailboom during the accident and the tail rotor had separated from the helicopter. Examination of the engine revealed the No. 6 piston had disintegrated catastrophically, which caused additional internal damage to the engine.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have conducted a preflight engine check to identify issues.

NTSB coding

Evidence available

  • Photos
  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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