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I sent the following to Van's Aircraft, but figured that someone on this list might also benefit.
I was concerned by the fact that the builder of the RV3 I bought had drilled a hole through the left elevator steel rod for the trim cable. I was worried that it would weaken the torque rod too much. See attached picture.
Today, during preflight, I discovered the real reason I should have worried. The trim cable wire had fractured at the point where the cable enters the rod. Passing the cable through the rod creates too small bend radius on the trim cable from where it comes out of the rear elevator spar and enters the hole in the rod and caused the cable wire to fatigue fracture.
Oddly, I believe I made at least one flight with this broken cable without noticing. I can't explain how that's possible unless the airflow over the elevator always puts the trim cable wire in compression.
I'm alerting you to this in case you notice someone else passing trim cable through the elevator torque rod. The danger for flutter is obvious.
Finn
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