Mmmm ....
Interestingly .... if you have an issue with the ball not playing games correctly (pls excuse the pun) you may find that if the aircraft is placed in the 'rigging' position that they may in fact have been installed incorrectly ... also the balls may indicate differently across a wide cockpit ... I have had issues with both 412s and 212 with this .. especially after rebuilds if the panels have had major work done on them.
Also ... the airframe has to be 'straight' for the balls to show correct trim.
