Hydraulics Use

[Dean_Dolph]

A thread on hydraulic pre-rotators reminded me that hydraulics is an interesting subject and I've often wondered what the negatives are in using them in homebuilt aircraft control systems and etc.

The routing of tubing would certainly be easier than the control tubes or push/pull cables we use now. I recognize that there would be tube anchoring details to work out and the sizing of the supply and drive cylinders would present a new challenge but one that shouldn't be hard to determine. Cleanliness and purging the system of air would be paramount in maintaining the system.

The toughest design problem would probably be the linkage of the controlled point with the hydraulic drive cylinder. Whether there is a weight penalty or not would have to be determined. Also, I'm not sure what kind of confidence level we can have in a hydraulic cylinder. Obviously commercial aircraft have confidence in hydraulics. Any one have thoughts on this subject?