CS AMG-AC Silicone Wax Corrosion Inhibitor (CS G7008)
Eurocopter CM No. - 323.
Fenestron (tail rotor within a protective housing) blade corrosion affects all helicopter tail rotor blade systems over time and becomes more extreme in helicopters operated in dusty, marine or coastal conditions. Such corrosion adds significantly to operational maintenance.
The left image illustrates the distal end of a fenestron blade within its housing. The right image illustrates a magnified view of the results of the corrosion/erosion cycle caused by initial corrosion of the aluminium alloy blades followed by the severe erosion of the corroded surface by the very high shear forces generated at rotation speeds of up to 6,000 rpm and impacts with air borne particulates. The corrosion appears to be more intense at the distal end of the blades and this is to be expected at the high tip speeds of the rotating blades and the tendency for a higher air pressure to occur at the distal end as a consequence of centrifugal forces applied to the air and particulates especially in the boundary layer. This conclusion is supported by the appearance of longitudinal (radial) grooves in the blade surface particulary close to the leading edge (top of images)and an almost total lack of circumferential grooves.
Not all fenestron blades are fabricated from aluminium, some are composites with a metalic leading edge. The leading edge may be zinc galvanised steel but zinc is very susceptible to chloride corrosion, however, zinc is among the most strongly protected surfaces by the CS AMG-AC Wax.
Fenestron Corrosion Inhibitor CS AMG-AC Silicone Wax (CM323) prevents corrosion of the alloy by forming an inhibitor film on the surface of the blade preventing moisture and salts from corroding the surface. The wax has been extensively field tested by Cairns Corporation and Eurocopter for more than two years and found to be significantly superior to previous treatments. Click the left image to open the Information Notes and the right image to access the MSDS. Both documents can be downloaded from the Product Manuals link at the bottom of the Contents Page.
Time taken to reapply the grease - 2 minutes. Image and notes courtesy of R. Green.
