Thanks for the reply rigidhead,
Our aircraft had its six year service and had to have the head completely stripped down, which of course may have disturbed a few things, so I had the track and ballance done at maintenance, which resulted in most of the washer weights on the blades being removed.
Track and ballance were just about bang on, but it gave the aircraft some very unusual vibrations through the floor.. Which I later found out it needed the 3per doing.
So we went to have them done with the microvib II,
Again it turned out that they were way out, we tuned them to 414 rrpm, which I think may need doing again at 411/412 rrpm as that's what I trundle round at ...
So when we do the underneath hammers next time is it worth doing the one in the front ? And is it tuned in exactly the same way as the others ?
Eg. 3xrrpm ?
Thanks for and help or advice,
Nelly