When you do a cyclic pushover, the nose goes down and the tail goes up. This puts the tail rotor’s thrust “line” above the CG – so the thrust rolls the helicopter. This is really only an issue with a 2-bladed rotor like the Bell 207, Huey, R.22, R.44 and so on.
Wow, I can't believe I hand' thought of that...that makes complete sense...the rotor going above the CG of the heli when yhou push the cyclic down.
And I think I get the low RPM thing too now. I think what I was forgetting was that the R22 usually operates with excess power available. So say the pilot pulls on the collective ( increases pitch of blades, more drag, larger lift) the rotor RPM would normally go down. So the governor asks the engine to provide more manifold pressure, and since it has excess MP, it brings back the RPM to nomial. So now, you got higher pitch for same RPM...thus more lift...and the helicopter climbs.
Now where the trick is...is when you reach the limit of this excess engine power.
Say you are closer to the limit...and you pull on the collective (same stuff, higher drag, more lift) so lower RPM , and the governor asks the engine for more power to keep the RPM up. Well, in this case there is no excess power, so the engine CAN'T maintain rotor RPM, and thus it goes below 104% (the optimal...for lowest drag etc).
Well, if the pilot requires excessive collective, and the engine is at it's limit...then obviously the RRPM is going to plummet...and you are going to have an extremely low RRPM...that might not be enough for autorotation...thus you are screwed.
That's my understanding at the moment, which seems to make sense to me from a technical standpoint.
Archer