Pilot Debrief

LOBB KENNETH CH 701 near Murfreesboro, TN — 2009-08-07

Final reportERA09LA446
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Date
2009-08-07
Location
Murfreesboro, TN, USA
Aircraft
LOBB KENNETH CH 701
Registration
N75644
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

A total loss of engine power due to the improper installation of the alternator drive gear.

NTSB narrative

According to the pilot of the experimental amateur-built airplane, about 15 minutes after departing the airport, and while flying approximately 1,000 feet above ground level, the engine lost power. The pilot immediately established the airplane in a glide, and began looking for a suitable landing site. He asked the passenger to attempt an engine restart, but the passenger was not successful. The pilot subsequently performed a forced landing to a pasture, which caused the nose landing gear to buckle and resulted in substantial damage to the airframe. Postaccident examination of the engine revealed that the alternator drive gear had sheared and jammed the accessory drive gears. Additionally, the alternator drive gear retaining nut did not have a cotter pin locking device installed, likely allowing the nut to back off. The airframe had accumulated 43 total hours since being assembled and the engine had accumulated 46 total hours since the most recent overhaul.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have checked engine components more thoroughly before flight.

NTSB coding

Evidence available

  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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