whats the technical cause of the massive two-per vibrations of an airworthy Huey
You mean asymmertical negative pitch at full down collective?
Well I can see how the rigid head of a BO would translate uneven lift into mast torque and vibration, but a teethering head would simple have one blade tip lower than the other, tilt accordingly and not "tell the frame" about it, no?
Well I can see how the rigid head of a BO would translate uneven lift into mast torque and vibration, but a teethering head would simple have one blade tip lower than the other, tilt accordingly and not "tell the frame" about it, no?
That description sounds like the condition of "bouncing rotorshaft" should be avoided at all cost, because it stresses everything, from MR bearings to pitch links and blade bearings.
But wouldn't that rotorhead + mast banging up and down create a clearly noticeable and rather frightening noise?
But wouldn't that rotorhead + mast banging up and down create a clearly noticeable and rather frightening noise?
However, in some situations the minimum blade does not get adjusted out or it is very close to the extremes for the stated auto RPM settings. This is also mentioned in the Bell explanation. So the maintenance solution to fix this bounce on the ground is to readjust the autorotation RPM which works most of the time. Or, you can continue to pull in a little collective everytime. However, in some scenarios pulling in a bit of pitch can create other issues.
Well just my opinion but
1) Check that outo RPM is correct for the ambiant conditions. Particularily if you have changed operations from hot to cold. Adjust as required.
2) zero the trim tabs.
3) empty the blade bolts of any weights. ( we one found weights in both blade bolts)
4) Do a complete track and balance. This is also a good opportunity to fine tune idle settings, gen matching and all the other small stuff you have been meaning to do.
5) If that solves the problem do another check of auto RPM and return to service.
6) problem is not solved check all the weird stuff.
I think that a T+B should be done every 100 hrs. A smooth aircraft has fewer snags.
1) Check that outo RPM is correct for the ambiant conditions. Particularily if you have changed operations from hot to cold. Adjust as required.
2) zero the trim tabs.
3) empty the blade bolts of any weights. ( we one found weights in both blade bolts)
4) Do a complete track and balance. This is also a good opportunity to fine tune idle settings, gen matching and all the other small stuff you have been meaning to do.
5) If that solves the problem do another check of auto RPM and return to service.
6) problem is not solved check all the weird stuff.
I think that a T+B should be done every 100 hrs. A smooth aircraft has fewer snags.
