Service difficulty report · Brushes · Cirrus SR22

Difficulty date
May 6, 2010
Submitted
May 14, 2010
Operation
General aviation
Filed by
YD5R855Y
Cirrus Design Corporation
Aircraft
N462SR
Make and model
Cirrus SR22
Aircraft serial
2495
Part
Brushes
Part number
ALE13A
Condition
Worn
Location
Alternator
Part time
749 hours
Component
Alternator
Component part number
ES10024
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

ALTERNATOR WAS WORKING AT TIME OF REMOVAL FOR OTHER DISCREPANCY ((YD5R)) (LEAKING SEAL). BRUSH HSG WAS REMOVED TO CHECK CONDITION DUE TO TIME ON COMPONENT. UPON REMOVAL (SEVERAL PIECES OF THE BRUSH ASSEMBLIES FELL OUT OF HOLDER. BOTH CARBON BLOCKS WERE WORN TOO NEAR MINIMUM .25". ONE BRUSH HAD BROKEN COPPER WIRE FLUSH WITH CARBON BLOCK. COPPER LEAD WAS MISSING COMPLETELY. THE BRUSH HAD ITS COPPER LEAD COMPLETELY SEVERED AT MID SPAN (WIRE IS ABOUT 1 INCH LONG BETWEEN CARBON AND CONTACT BUTTON. THE CARBON BRUSHES ARE CONSIDERED A WEAR ITEM. IT IS EXPECTED THAT THE CARBON WILL WEAR DOWN OVER TIME. HOWEVER, BROKEN OR MISSING WIRE LEADS SHOULD NOT BE CONSIDERED NORMAL WEAR. THE COPPER LEAD NEEDS TO BE MORE ROBUST. THE CURRENT DESIGN IS TOO FRAGILE FOR ITS WORKING ENVIRONMENT.

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