Service difficulty report · Bearing · Robsin R44RAVENII

Difficulty date
December 14, 2009
Submitted
January 19, 2010
Operation
General aviation
Make and model
Robsin R44RAVENII
Engine
Lyc IO540AE1A5
Part
Bearing
Part number
22021081806
Condition
Worn
Location
Magneto
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 DUE TO HIGH MAG DROP AT RUN UP. WHEN MAG WAS REMOVED FROM ENGINE CUSTOMER NOTICED THAT THE BEARINGS FELT ROUGH. MAG WAS DISASSEMBLED AND THE INNER RACE OF THE LARGE BEARING WAS FOUND TO BE EXTREMELY WORN AND THE MAG HAD SOME OIL IN IT. UPON FURTHER DISASSEMBLY TO INSPECT MANUFACTURER OF BEARINGS THE OUTER RACE OF THE SMALL BEARING WAS EASILY REMOVED FROM THE DISTRIBUTOR HOUSING, WITH EVIDENCE OF THE BEARING SPINNING IN THE ALUMINUM. THE BORE WAS MEASURED AT 1.1035 INCH (MAX. 1.1015" ALLOWED). THE BEARINGS APPEAR TO BE MANUFACTURED BY TEMPEST, AS ALL OTHER REPLACED PARTS IN THIS OVERHAUL WERE TEMPEST PARTS AND THE BEARINGS DONT HAVE THE SAME MARKINGS AS THE ORIGINAL TCM PARTS. THE MAG WAS OVERHAULED BY QUALITY AIRCRAFT ACCESSORIES INC. IN TULSA OK. AN EXCHANGE MAG WAS QUOTED TO THE CUSTOMER. (TC# 20091214009)