Checking the Tranny mounts can be done on the ground during the preflight as well....takes two folks to do it properly. One makes like King Kong and shakes the head fore/aft and left/right...while the other guy feels for movement within the mount/bolts and gearbox flanges. Doing a climbing turn will also point out any mount problems by generating a shuffle sometimes.
As previously described....stirring the stick at a hover or in slow forward flight works as well.
A loose lift link caused by worn bearings will cause some problems as well. Have seen some bearings fall slap out of the link when the bolts were removed. The problem disappeared with the installation of new bearings.
(Bell 204/205/212/412/UH-1A,B,C,D,H,K,L,M,N models)
Question:
Why do most "Huey" pilots fly with all of the cyclic friction removed....but Sperry requires a "pre-set" minimum friction when their AFCS is installed?
Does it not make sense for some friction to be left applied ala Sperry.....and thus dampen out some of the oscillations that will be caused by "feedback" from out of balance condidtions and PIO?