Pilot Debrief

CARR RV-4 near Arlington, WA — 2010-03-18

Final reportWPR10LA171
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Date
2010-03-18
Location
Arlington, WA, USA
Airport
AWO
Aircraft
CARR RV-4
Registration
N66PB
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Landing

Probable cause

The failure of both main landing gear's drag link bolts in overstress and the subsequent collapse of the landing gear during landing rollout.

NTSB narrative

The pilot said that when he took off and retracted the airplane's landing gear, only the tailwheel retracted. He lowered the landing gear and saw three green lights, indicating that all three landing gear were down and safe for landing. He then proceeded to his destination with the main landing gear down. During landing rollout at his destination, the left main landing gear collapsed. The airplane departed the left side of the runway before the right main landing gear collapsed as well. When the left wing's main landing gear collapsed outward, it damaged the wing structure and punctured the left fuel tank. The skin on the top of the right wing and the right aileron were wrinkled. Postaccident examination of the landing gear revealed that both main landing gear drag link bolts failed. These bolts were welded to the back of each main landing gear as part of their landing retraction system. Examination of photographs of the broken bolts by an NTSB metallurgist revealed that each bolt exhibited cantilever beam bending in overstress. The quality of the photographs was inadequate to determine if fatigue played a role.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have checked landing gear functionality before landing.

NTSB coding

Evidence available

  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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