John Dixson just posted something interesting in the HH-60 thread about the Sikorsky S-67 AFCS system using a variable rate Beep Trim system that was installed on the Blackhawk Prototype but was nixed by the US Army Test Pilots.
No doubt they had probably all grown up on Bell's and perhaps Chinooks with the standard old Force Trim Release system that incorporated a Thumb Release Button.
A lot of different helicopters used the same concept as did the old Huey.
Hopefully, he will be along to explain in better detail how that Variable Rate Coolie Hat thing functioned.