nighttrain
Senior Heliman
Location: Louisville KY
| Andy,
Your trailing blade grips probably are more stable, but thats uncorrecting (neg) delta. If you look at your rotorhead sideways, the pick off point (Ball) is to the left of the flybar (mainshaft).
It was hard to understand for me, but Wayne Mann figured it out. I hope he'll chime in again. It became clear to me that in neg delta, the blade is divergent (recieves further input), pitches further into a gust, and the rotor as a system "absorbs" the gust - rather than the helicopter. The rotors stored momentum overcomes the sudden gust. It only stands to reason but is often overlooked in these discussions: You have to have damping taking place for any pitch arm to operate in this fashion. No damping taking place - no delta. So it's almost a mute point w/ hard 3D type dampers. Many contest pilots flew with practically no resistance at all, way beyond the quote "soft dampers" or 60dm. If a fly lands on the tip of my rotorblade, it will dip 2 inches. It gets progressively harder as the blades get near the boom. Boom strikes seem to be the limiting factor in how soft you can go, and how well you can auto. Most people will tell you not to modify your manufactures rotor - with good reason too, so you may not see much public info on secret practices. But without damping, there is no delta. Good luck! |
