Lu said ,
"Try this: …snip…. In forward flight keep the cyclic in the forward-displaced position and move the cyclic laterally to the rigged neutral position. If I am right the helicopter will fly to the left. If it doesn't deviate from the flight direction I am wrong and I will shut up. It is a simple test and could take all of 15 seconds."
R.R.
Hang on. If you are in steady flight and you deviate the cyclic laterally of course the helicopter will deviate in the direction of the movement. Your assumption is that forward cyclic will cause the disc to tilt to the left and will thus need right cyclic to maintain the forward direction.
In solo flight the cyclic is across to the LEFT and forward (as previously stated it hangs tail low and has tail rotor drift thus needs forward & left cyclic . No surprise there. This applies to forward flight as well as hover. Returning it to the neutral position is rearward and right.
What I did:
At the hover to return it to the neutral position causes lift in the front of the disc. I was not prepared to sustain that rearward drift for more than an instant while trying to visually fixate on the disc. Easy to get a sort of disorientation and a reactive driving the tail into the ground. I suspect there was some right tilt of the disc because the helicopter went that way but I didn’t see it so I can’t say I proved it. So from hover to neutral cyclic position caused rearward and rightward movement of the helicopter.
From the hover position (cyclic slight forward and to the left) to translation and climb needed forward cyclic only with definitely no further lateral deviation.
To return it to the rigged neutral position (in flight) caused a sudden climb and deviation to the RIGHT. Again no surprise because those effects are fully explainable by the CofG movements when solo.
So in short it did the opposite lateral to what you expected but it was explainable. What it would need is to load the helicopter to a C of G that allowed the machine and rotor disc to both hang horizontally at the hover to at least counter those effects.
Lu:
"Or, try this:
At your next start up place the cyclic in the rigged neutral position.
With the blades turning at 100% pull a slight amount of collective to get the blades to cone slightly. Move the cyclic forward from the rigged neutral position. Note what the blade disc does. Does it tip down over the nose or does it tip to the left. Another fifteen second test neither of which will place you or the helicopter in danger. "
RR
Result:
This was easy and absolutely unequivocal. I even moved my body across so I was looking from the centre of the aircraft.
From the rigged neutral position on the ground at 100% RRPM with slight up collective.
Forward cyclic = downward tilt on disc directly over the nose.
Rearward cyclic = upward lift in front of disc
Right cyclic = right tilt
Left cyclic = left tilt