I am not sure that your take on these accidents are correct or perhaps these are different accidents. "
Perhaps you can post a link to the reports as I would like to read them.okflyer wrote: where slipping into the wind (strong crosswinds) close to the surface (100 to 300 ft.) slowed down the rotor so much that the copters stalled and falled to ground like stones.....that wake turbulances caused by obsticals in a crosswind situation while using side sleep technique let the airflow collapse or flow over the rotor.
The summary below, as discussed on the Rotaryforum of these accidents, explained the cause of these accidents for me. Remember during normal pitch inputs the horizontal stabilizer is suppose to "protect" you from a push over, but during a side slip there is no horizontal stabilizer to protect you or work in the anti-cyclic input direction and coupled with the yaw angle that will cause a roll moment and engine torque induced roll moment to the right will cause these accidents.
"only if you just consider the rotorsystem is there no yaw-roll coupling in a gyro (and that's true only if you neglect coning). You need to take into account the vertical shift in the center of pressure as the yaw angle increases. This is due to the shape of the fuselage and very pronounced in semi-enclosed gyros such as Magni, ELA and MTOSport. In those, and similar, gyros the center of pressure shifts downward below the CG with increasing yaw angle. This induces a roll moment.
I agree with you that uncoordinated rudder and stick movements, as may happen when you get out of a side slip, can lead to an increase in bank angle. In general, there are a number of things that all work against the pilot in the three accidents of that kind that I'm aware of:
1) Downward shift of the center of pressure with increasing yaw angle will induce a roll moment.
2) Engine torque induces a roll moment to the right (all three accidents torqued over to the right).
3) In at least two cases there was some partial unloading of the rotor, which reduces the moment counteracting roll.
4) Uncoordinated control inputs can lead to a preponderance of lateral cyclic input resulting in an unintentional roll.
5) Flight in gusty conditions, where gusts from the right increase the rolling tendency in that direction."
From the above with all three roll overs to the right, it seems that the engine torque is a major contributor to these rollovers, especially at high power settings.
Perhaps you can explain to me why airflow over the rotors in side slip will collapse or flow over the rotors, causing it to stall, but not in normal flight or even in a slight nose down attitude. I haven't checked this yet but I would guess that the angle of the rotor in a side slip will be the same as in a slight nose down attitude in normal flight. You might have less forward speed in a side slip, due to the increase in drag, than in normal flight for the same rotor angle and that might reduce your lift and you might loose altitude, but not fall from the sky like a rock as you explained.
Perhaps the aeronautical engineers amongst us can comment and clarify this for us.
I also like the external fuel tanks a lot. Any idea how much lift they generate during normal flight? I think I saw somewhere that Arrow-copter has published percentages at various speeds.