This month’s Ask a Tech Q&A come from the owner of a Lycoming O-320-D2A engine that had a noticeable vibration when it came out of a paint shop. And, dangerously erroneous heading errors with an old King electric HSI requires logical troubleshooting. First, the vibration trouble.
“After coming up empty during random troubleshooting attempts, my mechanic suggested that we try several different prop positions to see what impact it might have on the vibration problem.