Hingless Rotor wrote:
I had put it down to the SPAS applying a correction to the stick position as a result of the applied cyclic when correcting the pitch up, but have since come to the conclusion that it is an instability problem. When it happens you get the distinct feeling that you have no pitch control for a couple of seconds.
Haven't flown the BK, but the MBB BO105 has a very similar rotor with similar characteristics. One day, up high and scooting right along, I caught a little updraft (I guess) and the nose pitched up. And up, and up. I kept feeding forward cyclic in, with no response, thinking, "This is a bit odd, eh what?" Finally I did lower the collective and returned to controlled flight. I came to the conclusion that my little BO-peep did not like high-altitude flight all that much.