Gawd theres some knowledge out there in pprune land. Thanks for the info guys.
But it still sounds to me like my original proposition stands. That "Yaw damper rudder inputs are not an input to the rudder artificial feel units on any aircraft I know about."
So early 707s had yaw dampers in parallel with the rudder pedals - but there was no artificial feel unit since the rudder controls were entirely a manual affair. You say that more recent 707s had a Q-feel unit on the rudder pedals, but was the yaw damper in parallel on these models? Or was it in series?
So the Saab requires the yaw damper to be switched off for take-off and landing - still hasn't got me convinced that its anything to do with yaw damper inputs to an artificial feel unit. (Does the Saab have a powered rudder?? Does the Saab have an artificial feel unit for the rudder pedals??)
So I am still unable to agree with V2Climb's proposition that "Some aircraft take of with the yaw damper in all the way from the start of the roll. Some other means of steering is needed ie: a nosewheel tiller.(BAE 146 for example)"
And, 411A, thanks for the interesting story about the Feds screw up at TWA. I spose you are well aware of the RAAF (Royal Australian Air Force) B707 training crash off the south east coast of Australia about 10 or 12 years ago when the officer in charge (who was sitting on the jump seat) decided to switch off the rudder boost while two engines on the same side were shut down, and while the aircraft was at 5,000 feet over the ocean? The aircraft rolled over and went into the water with a hell of a thud in well under 30 seconds. May all five crew members on board RIP.