Service difficulty report · Bearing · Bolkms BK117A3

Difficulty date
May 25, 2001
Submitted
July 10, 2001
Operation
Air carrier
Aircraft
N163BK
Make and model
Bolkms BK117A3
Aircraft serial
7063
Part
Bearing
Condition
Failed
Location
Bellcrank
Component
Bellcrank · Urocop
Component part number
1117441011
Stage of operation
NR
How discovered
O
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

THE AC EXPERIENCED ABNORMAL UNCOMMANDED YAW AND ROLL MOTION ON LANDING. LATERAL CYCLIC BELLCRANK CENTER BEARING FOUND TO HAVE FAILED. THIS CAUSED THE BELLCRANK TO HAVE EXCESSIVE PLAY RESULTING IN LOSS OF POSITIVE CYCLIC CONTROL. AC PERFORMED SUCCESSFUL LANDING WITHOUT DAMAGE, HOWEVER THE LOSS OF CONTROL WAS QUITE SEVERE. AN INSPECTION OF THE BELL CRANK BEARING ON 6/19/2001, FOUND THAT THE BEARINGS WERE MISSING. THE PART MAY HAVE AS MUCH AS 6065 HRS. IT APPEARS THAT THE BALLBEARING INSTALLATION SLOTS MAY HAVE LINED UP AND ALLOWED THE BALLBEARINGS TO BE EJECTED FROM THE BEARING, ONE AT A TIME.