Seems a lot of people don't really understand this........
In days gone by I remember having to carry out this one:
05 MAY 1998
SB 600N-011
CYCLIC CONTROL MIXER LINKS REPLACEMENT
(EIGHT DEGREE PHASE SHIFT RECOVERY)
Reason:
To recover the cyclic phase shift caused by adding the sixth blade to the main rotor system.
Complying with the requirements of this Bulletin will result in reduced pilot workload. (Read - meet FAA certification requirements)
The fix was to fit a drive link to the stationary swashplate with an 8 degree offset. The control links all ended up kind of leaned over.
Flying it before and after produced little change to the total "workload" however.
The most significant change from the 4 and 5 bladed head was the shortening of the pitch horn so you could fit all six blades on. This resulted in the total phase adding up to approximately 82 degrees by all accounts as the pitch horn is not in line with the feathering and flapping hinge point.
This aircraft, which has not been the most successful, has some very interesting engineering anomalies. Most of it was driven by trying to stay away from having to develop a new main rotor blade. The rotor produces the required thrust but unfortunately not at the ideal A of A for best L/D.
As to the Robinson comments. It works - kind of!!