Crab wrote:
(snip)
...I point out that a yaw input in forward flight (without moving the cyclic or collective) produces a roll in the SAME direction - this is the secondary effect of yaw.
Whoa! Hold on! Crab, it has been my experience that in many small helicopters, a slight yaw to the right will absolutely produce a roll to the LEFT due to the extra drag caused by the the cabin being out of trim. And vice-versa. And it's very dangerous at high a/s in underslung systems because it plays hell with the flapping angle and mast/hub clearances. ...As many dead Cobra pilots can attest.
This is the opposite of the "dihedral effect" we've come to know and love in airplanes (where you can pick up a dropped wing with opposite rudder). Remember, our tail rotors are attached to the airframe, so yaw changes do not immediately effect the rotor...which is why it's harder to hold a localizer with pedal adjustments as you can do in a plank.
It is quite easy to maintain straight and level flight in a helicopter with the cyclic frictioned down tightly. Trouble is, yawing also makes the nose drop, so pedal inputs have to be tiny.
To Vorticey. You wrote:
would it have something to do with the position of the cyclic during foward flight? ie, right and foward of the hover position (anti clockwise rotation)?
would the positions you are talking about be the same distance from the flight position??
Sorry, matey, but the roll
rates actually don't have anything to do with cyclic position.