Medium, the frequency changes with throttle movement so it is directly related to the rotation of engine, Remember it only occurs if there is a g loading present.
Have at this stage eliminated any airframe input, did an inflight inspection to see if any gear doors or panels were not flush or fluttering...nothing so at this stage I am firmly convinced it is engine related.
New Mags,leads,plugs,lord mounts in an effort to clear this problem with no joy
Last edited by Fleep; 8th Mar 2013 at 08:19.