PA28-181, just out of annual, with brand new prop.
Pre-flight, runup, takeoff roll, climb and cruise all seemed normal. However, when I reduced power to about 2,100 rpm to get under the Philly class B shelf, I suddenly got a strong vibration. Application of carb heat (I was thinking icing) had no effect, engine gauges all normal and in the green. When I increased throttle, the vibration went away above 2,250 rpm. Power output at various rpm settings seemed normal.
I decided to return to Brandywine rather than a precautionary landing at Morgantown. Throughout the pattern, landing roll, and taxi back to the hangar, I could feel the vibration, and the frequency seemed to be governed by engine rpm.
I have flown the aircraft since the new prop was installed and hadn't noticed anything like this vibration before.
Any thoughts on what might cause this?
Pre-flight, runup, takeoff roll, climb and cruise all seemed normal. However, when I reduced power to about 2,100 rpm to get under the Philly class B shelf, I suddenly got a strong vibration. Application of carb heat (I was thinking icing) had no effect, engine gauges all normal and in the green. When I increased throttle, the vibration went away above 2,250 rpm. Power output at various rpm settings seemed normal.
I decided to return to Brandywine rather than a precautionary landing at Morgantown. Throughout the pattern, landing roll, and taxi back to the hangar, I could feel the vibration, and the frequency seemed to be governed by engine rpm.
I have flown the aircraft since the new prop was installed and hadn't noticed anything like this vibration before.
Any thoughts on what might cause this?