Vortex what?
Thanks for starting this thread. I too am interested in taking the course at some point. Seems like one must really plan ahead!
For the moment I'm going to respond to the 'off-topic' argument however. Sorry
RW-1
Hey, welcome back. Back when you and Lu were slamming each other I thought you were a bit harsh. I'm happy to see you step back from the fray this time. Thanks
Lu,
I've responded before regarding the 18 degree offset and the reason for it. I'm not going to repeat myself because I don't think it's any use. However, I will make one point.
You recently said, "I have contacted a member of this forum who is an instructor on R22 and R44 and I am awaiting his response. In a personal email he indicated that the cyclic is to the right of center in normal flight. That was demonstrated using a stick plotting board. If he does perform the test, it will put this matter to rest."
Unfortunately, I don't think this will put the issue to rest at all. Remember that even the rotor is not the sole source of aerodynamic forces and moments on the helicopter. As you may know, translating tendency is the effect that the translational force of the tail rotor has on the helicopter, most noticeable during hover. It must be offset by lateral application of the stick (to the left on a Robbi). Since the vertical stabilizer acts to provide some yaw force during fast forward flight (roughly proportional to forward speed^2) and the rotor torque that needs to be counteracted by the tail rotor/tail fin decreases with speed, it stands to reason that the need for tail rotor thrust (and thus application of lateral cyclic to overcome it) will decay as speed increases. So if you want to make a plot of stick position, in theory it should start to the left of a longitudinal line at hover and slowly approach it as speed increases. This doesn't account for transverse flow effect but that will just manifest itself in a leftward bulge along the line, between hover and cruise. The plot that you say someone has created during flight seems to be quite well described by this translating tendency theory. I'm sure it's not the only effect though.
I'm not sure why you're so darned intent upon making us all understand your point. It's clear that the theory behind all of this is beyond your abilities--probably beyond mine as well. With several very knowledgeable people refuting your theory however, and no concrete evidence in your favor (I don't think your accident statistics support your assertion very much), I just wish you'd do some more research on your own before crying foul and complaining about how dangerous these little beasts are.
Did you ever go out to an airport where you can watch the disc as someone moves the stick exactly fore and aft or side to side? Did you ever get back to Ray Prouty, who I think misunderstood your question the first time? In-flight tests as you've noted above are simply too complex to prove anything. We've heard everything you've said before, so saying it again won't change our response. If you go to a library and bury your head in some reading materials (I've mentioned Johnson, though it's not an easy read--try the new Leishman book, it's being reprinted mid-November and reads very easily) and come back with a good understanding of offset hinge and delta-3 flapping dynamics, or even just the dynamics of a second order system, we might pay a bit more attention. At least I will
Until then it's just like arguing with someone who just saw the Wright brothers fly, yet tries to prove mathematically and physically why manned heavier-than-air flight is impossible. Very frustrating...
P.S. Nice to see that not all your posts have the thumbs-down icon as before
