To: 212 Man
I guess you are going to have to accept that fact. If you want to prove it to yourself take a ride in a Bell helicopter equipped with a Nodamatic suspension system. Open up an inspection port that will allow you to see the transmission. When the pilot pulls collective you will see the transmission move upwards. As the pilot introduces forward cyclic and the helicopter starts to move forward the trannie will start to rise and fall. As the speed builds up to cruise the transmission can be moving up and down by several inches depending on the helicopter type. The 214 is most pronounced.
When the blades are aligned with the longitudinal centerline and several degrees on either side of the centerline the blades lose lift as they are aligned with the relative wind. This decreases the lift and the transmission will fall. As the blades rotate past the center and several degrees on either side they generate more lift and the transmission will rise. I don’t know if they ever installed the Nodamatic on the 212 and if they didn’t then you can feel a vertical beat when flying. This is caused by the up and down movement of the transmission, which in the case of the 212 is limited, by the movement allowed by the transmission elastomeric mounts.
As the transmission moves in relation to the fixed lift link the transmission will also rock in a vector from forward left to rear right and when maneuvering, this relationship between the lift link and the transmission will cause the pylon or mast to move in an orbital motion and that as I see it is what causes pylon rock.
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The Cat