Service difficulty report · Bolt · Diamon DA20C1

Difficulty date
July 18, 2014
Submitted
March 12, 2015
Operation
General aviation
Make and model
Diamon DA20C1
Aircraft time
6,084 hours
Engine
Cont IO240B
Part
Bolt
Part number
2224120001
Condition
Broken
Location
Alternator Pivot
Part time
1,438 hours
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

(CAN) DURING REMOVAL OF COWLING FOR OIL LEAK CHECK IT WAS NOTICED THAT THE ALTERNATOR PIVOT BOLT WAS LOOSE. FURTHER EXAMINATION FOUND THAT THE BOLT WAS BROKEN IN THE THREADED PORTION OF THE ALTERNATOR BRACKET. A NEW BRACKET WAS INSTALLED AND WHEN THE MECHANIC WENT TO INSTALL A NEW PIVOT BOLT HE FOUND THAT THE NEW BOLT WAS NOT THE SAME AS THE OLD ONE. A RECORD SEARCH OF INSTALL FOUND THAT A NEW BOLT WITH THE SAME PN, AND HEAD MARKINGS HAD BEEN INSTALLED JUST OVER A YEAR PRIOR. THE SHANK LENGTH OF THE 2 BOLTS WERE DIFFERENT BY ABOUT .1250". THE OLD BOLT WAS THE LONGER OF THE 2. IF INSTALLED IT WOULD NOT BE OBVIOUS THAT THE BOLT WAS BOTTOMED OUT AS THE PROPER TORQUE COULD BE REACHED ON THE BOLT. THE PIVOT BOLT IS NORMALLY THE LAST BOLT IN THE SEQUENCE TO BE TORQUED. THERE IS A CRUSH TYPE SPLIT WASHER UNDER THE HEAD OF THE BOLT THAT TAKES UP THE SPACE. THE SUPPLIER OF THE BOLT WAS CONTACTED FOR FURTHER CLARIFICATION AND INFORMED US THAT THE SHORTER SHANK BOLT WAS THE CORRECT ONE. THEIR QTY DEPARTMENT IS LOOKING INTO THE ISSUE.

More about the Diamon DA20-C1