Pilot Debrief

GRUMMAN G164 near Juliaetta, ID — 2016-03-12

Final reportWPR16LA082
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Date
2016-03-12
Location
Juliaetta, ID, USA
Aircraft
GRUMMAN G164
Registration
N6894Q
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

A partial loss of engine power due to a crack in the No. 2 cylinder.

NTSB narrative

The commercial pilot was conducting an agricultural application flight. The pilot reported that, while maneuvering the airplane about 300 ft above ground level, the engine experienced a partial loss of power. Unable to maintain altitude, the pilot conducted an emergency landing to a field, during which the airplane landed hard and nosed over, coming to rest inverted. Postaccident examination of the engine revealed that the No. 2 cylinder head exhibited a circumferential crack of its barrel between the cooling fins. The Federal Aviation Administration had previously issued an airworthiness directive (AD) to address cylinder head cracking on the accident model engine. The AD required periodic visual inspections for cracks in the cylinder heads at specified intervals of time in service (every 100 hours for the accident airplane). According to the engine maintenance logbooks, the AD was last complied with about 35 hours before the accident. The previous inspections to this were sporadic, indicating that neither maintenance personnel nor the owner(s) were regularly complying with the AD.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Performing required inspections on engine cylinder heads as per AD 78-08-07.

NTSB coding

Evidence available

  • 4 docket documents
View NTSB final reportView NTSB docket

Docket documents4

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