NONE · Robinson R44 · 2018-07-29 · Bettles, AK, USA
Event
NTSB number
ANC18LA058
Event ID
20180731X84010
Type
Accident
Date
2018-07-29
Location
Bettles, AK, USA
Coordinates
66.860557, -151.645278
Injuries
Highest injury
NONE
Fatal
0
Serious
0
Minor
0
Uninjured
3
Total aboard
3
Aircraft
Make
Robinson
Model
R44
Registration
N744AK
FAR Part
PUBU
Engines
1
Damage
SUBS
Conditions
Light
DAYL
Weather
VMC
Probable cause
Maintenance personnel's application of insufficient preload on the attachment hardware for the idler gear shaft during engine overhaul, which resulted in the dismounting of the idler gear shaft assembly due to wear and deformation and the subsequent total loss of engine power. Contributing to the accident was a mechanic's failure to identify metallic particles contained in the oil filter element at the most recent 100-hour inspection.