Service difficulty report · Bolt

Difficulty date
August 24, 2014
Submitted
May 24, 2016
Operation
General aviation
Propeller
Hartzl HCD2MV207
Part
Bolt
Condition
Failed
Location
Prop Clamp
Stage of operation
IN
How discovered
V
Nature of condition
K
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

ON INSPECTION, AFTER AN ACCIDENT, IT WAS DISCOVERED THAT THE PROPELLER WAS ASSEMBLED WITH USED NUTS AND CONTAINED EXTREMELY OLD GREASE. IT APPEARS THAT THE NUTS ON THE BLADE CLAMP WERE VERY LOOSE AND THE PROPELLER BLADE HAD SLIPPED 5 DEGREES. ONE CLAMP WAS CRACKED AND THE CRACK SHOWED SIGNS OF CONSIDERABLE RUBBING. THE PROPELLER SHOWED EVIDENCE THAT IT HAD IT MAY HAVE COME APART IN FLIGHT DUE TO A FAILED CLAMP BOLT. THE GREASE HAD HARDENED TO AN EXTENT THAT IT HAD BECOME A SOLID AND COULD NOT BE PENETRATED BY A SHARP OBJECT.