Originally Posted by paglia
Quick question: Is there are mechanical linkage (ie. cables) between the throttle and the engine fuel control unit?
I know in normal N1 speed control the throttle lever position is picked up by a variable resistior in the throttle quadrant, but I would like to know if when operating in N2 mode there is an actual mechanical linkage between throttle and engine fuel control (and if so, I'm assuming you'd have a governor with flyweights in the HMU).
The short answer is yes, there is a mechanical linkage. I should add that N1 speed control doesn't kick in until 79% N1,
provided the speed switches are on. These switches are deferrable, however, in which case we are back to all-mechanical controls. The thrust settings get much "jumpier" in that case.
I should also add that the -3A1 engine is the same way.