Originally Posted by
meleagertoo
This image surfaced in the What Flying Machine thread on the History and Nostalgia platform. (Post 5948) .......................... It's a close-up of an Air Lualdi L59 and many other pics available show these weights hanging from the servo-paddles. Anyone know what they are for and how they work?
Hi
meleagertoo, is it a cheap/simple/late(?) application of the "Bell" part of a Bell/Hiller system of damping as described
here? I've found other similar refs (more formal refs) but this ref seems to have an explanation of the combined system that I can actually understand ...... which is handy.
The 'classic" weights on the Bell system (such as the Bell 47) seem to be a fixed bar (to, presumably, transfer the forces back to the hub) and both the weights (Bell 47) and the stub blades (such as the Hiller 12) seem to serve the same role in preventing over-controlling through too rapid a head response to a control input. So, perhaps, this was a bit of a late Mod adding in the "bar system" when they found the "paddles" couldn't quite hack it on their own?
But, you wisely ask, "So why not just add fixed weights to the tips of the stub rotor paddles?"! Ahhhhhhh, well you've got me there!!!!!!!!
And, if the bit of "string" snaps in flight (bird-strike maybe?) you'd suddenly end up with a rather interesting "1R" vibration too!
Anyway, just an idea................ Of course, it's all quite academic as helos should never be able to fly - says he having maintained them for several years and even tried to fly a few - the Gazelle having been the most fun!
Cheers,
H 'n' H