About three weeks ago I was on the last leg of a 2500 mile cross country and had just started the final descent from 8000 ft when my RV-8 started to vibrate/shake. I could not identify where it was coming from (controls, engine, tail, wings, etc,) before it stopped (after descending about 1500 ft).
Upon landing a thorough inspection of the plane turned-up nothing and all followiing flights were perfectly ok. In hindsight the only thing I could come up with was that perhaps I had failed to disengage the autopilot and that the shaking was the servo trying to resist the descent?
Last week on returning from another cross country, I had just climbed to 9500 ft and leveled off when the shaking/vibration started again. I immediately disengaged the autopilot and turned right and left (didn't stop it), flew up and down (didn't stop it), looked at all the control surfaces and they all seemed ok, checked the engine and it was ok......then, touched the brakes and the shaking/vibration STOPPED!
Problem solved. Evidently, at just the right angle, or airspeed, or something (only twice in 110 hours of flying) one or both wheels started turning and at a high enough speed one is slightly out of balance.
Just wanted to pass it on in case it happens to someone else.
Hope it helps save someone a little anxiety.
Upon landing a thorough inspection of the plane turned-up nothing and all followiing flights were perfectly ok. In hindsight the only thing I could come up with was that perhaps I had failed to disengage the autopilot and that the shaking was the servo trying to resist the descent?
Last week on returning from another cross country, I had just climbed to 9500 ft and leveled off when the shaking/vibration started again. I immediately disengaged the autopilot and turned right and left (didn't stop it), flew up and down (didn't stop it), looked at all the control surfaces and they all seemed ok, checked the engine and it was ok......then, touched the brakes and the shaking/vibration STOPPED!
Problem solved. Evidently, at just the right angle, or airspeed, or something (only twice in 110 hours of flying) one or both wheels started turning and at a high enough speed one is slightly out of balance.
Just wanted to pass it on in case it happens to someone else.
Hope it helps save someone a little anxiety.
