Service difficulty report · Bearing · Robsin R44RAVENII

Difficulty date
June 10, 2009
Submitted
August 3, 2009
Operation
General aviation
Make and model
Robsin R44RAVENII
Aircraft time
520 hours
Engine
Lyc IO540AE1A5
Part
Bearing
Part number
2202
Condition
Worn
Location
Magneto
Part time
472 hours
Component
Magneto
Component part number
106006169
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

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

What was found

(CAN) MAG WAS RECEIVED FOR A 500 HR INSP. BEFORE DISASSEMBLY, ROTOR WAS SPUN AND END PLAY WAS FOUND (0.0035 INCHES, MAX ALLOWABLE IS 0.0015"). THE MAG WAS DISASSEMBLED AND SMALL BRG (PN 2-202) WAS FOUND TO HAVE WEAR MARKS ON THE INNER RACE AND BRG CAGE WAS ALSO FOUND WORN. IT IS UNKNOWN IF BRG WEAR CAUSED END PLAY OR IF EXCESSIVE END PLAY CAUSED BRG WEAR. THIS MAG STILL HAD ORIGINAL WHITE TORQUESEAL ON ONE OF THE HSG SCREWS INDICATING IT HAD NOT BEEN DISASSEMBLED SINCE ITS MFG IN 2007. IN ADDITION, 1 OF THE 3 SCREWS HOLDING DISTRIBUTOR BLOCK TO HSG WAS FOUND BENT JUST UNDER THE CAPTIVE WASHER AND LOCKWASHER LOCATION. THIS DID NOT CAUSE ANY ISSUES IN THE MAG BUT DID SLIGHTLY INDENT THE POLYESTER DISTRIBUTOR BLOCK. CUSTOMER REQUESTED MAG BE O/H, BOTH BRGS WERE CHANGED, AND MAG WAS RETURNED TO SERVICE.