To: Flap40
Since 1968 I have worked as a Reliability, Maintainability and Systems Safety Engineer. One of the requirements of a Reliability Engineer is to prepare an FMEA or FMECA depending on the contract. The E in FMEA and FMECA stands for EFFECT as in Failure Modes EFFECT Criticality Analysis.
The binding caused by the wire brush was the failure mode. The effect was a jammed rudder control. I think I got it right the first time.