Test Method for Catalytic Carbon Brake Disk Oxidation
The scope of the test method is to provide stakeholders including fluid manufacturers, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This simple test is only designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions. It is not possible to set a general acceptance threshold oxidation limit based on this test method because carbon brake stack oxidation is a function of heat sink design and the operating envirnoment.
The current generation of runway deicers based on alkali metal acetates and formates have been shown to have a major negative effect on the oxidation resistance of carbon-carbon heat sinks in aircraft brakes. No standardized test currently exists to assess the impact of runway deicers on carbon heat sink oxidation. The test method defined in this AIR offers a quantitative procedure to evaluate the relative effect of various runway deicers on carbon brake disks.