http://www.mdhelicopters.com/helicop...escription.pdf
MD
SYSTEM DESCRIPTION600NŽ
[...]
3.6. Flight Controls
Primary flight controls in the MD 600NŽ are designed to be lightweight, simple to use and easy to maintain. Equally important, they are designed to
eliminate the need for hydraulic controls. All main rotor controls in the MD 600NŽ are of the push tube type. There are no grease fittings in the controls and required maintenance is minimized.