Nick, You said: "The myth that the Tail Rotor's position relative to the Main Rotor Head is a factor in the hover attitude has somehow evolved, much to the surprise of those who actually build these things."
I know you're a vastly experienced test pilot, and maybe I'm not thinking straight about the subject, but can you please shed some light on the following:
In your picture above, the translating and anti-translating forces, as you've labelled them, are vertically displaced. This creates a force couple, making the aircraft roll.
How far does it roll?
Until the opposing couple formed by the lateral displacement between the CofG (from which weight acts straight down) and the rotor hub (from which lift acts straight up) becomes large enough to be equal and opposite to it.
Obviously the greater the roll angle, the greater the displacement between the lateral positions of lift and weight, and so the more the opposing force.
Likewise, the pro-roll couple formed by the translating and anti-translating forces gets stronger the more vertically displaced they are from eachother, so it seems to me that the vertical position of the tail rotor with respect to the main hub is a major factor in how much roll you'll get.
You said: "The myth that the Tail Rotor's position relative to the Main Rotor Head is a factor in the hover attitude has somehow evolved, much to the surprise of those who actually build these things."
To my mind, the vertical displacement between these two determines the strength of the pro-roll couple, and is therefore far from mythical.
To put it another way, say you had a helicopter with a standard main rotor, central CofG, and two antitorque rotors, one on the nose pushing left and one on the tail pushing right.
If the two antitorque rotors were at the same vertical level, there wouldn't be any rolling.
If they were significantly displaced vertically, there'd be lots of roll, increasing with the displacement.
How is this any different to the main rotor / single tail rotor situation?
I rest my case, your honour.
