To: Grey Area
As I had indicated previously the subject of cross couple came up in a Robinson thread. I mentioned that the Robinson Rotor is rigged with the blades disposed from the lateral and longitudinal axes by 18-degrees during rigging of the flight controls. And as such, with a 90-degree phase angle the blades would in my opinion dip down to the left of the longitudinal centerline if the cyclic were displaced forward from the rigged neutral position. An Army Lynx pilot indicated in his reply to the posting that the Lynx rotorhead is rigged with the blades disposed 15-degrees from the respective axes when rigging of the flight control takes place. He indicated that on the Lynx with the blades rigged in this way and with a 90-degree precession angle the Lynx blades would also dip down and to the left when the cyclic was displaced forward. He indicated that there was an electronic “Black Box” that detected the left roll and compensated for it by modifying the input to the servos. I had also indicated that I might get the terminology mixed up. Obviously I did. Incidentally, your description of the ASE used in the Lynx is very similar to the ASEs that I was familiar with.
I feel that the reason I fought your explanation was because of the description given by the Army Lynx pilot and my unwillingness to accept your description when you used the term cross couple. I understood it as a problem that manifested itself due to the way the helicopter is rigged. I still believe that to be true for the Robinson.
I anxiously await your drawing of the of the Spider arm.
If you have the capability you can send it to me via email.
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The Cat