The National Academies Press

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From page 8... ... As such, thermal oxidation usually will not occur until the anti-oxidant layer is disrupted. Dynamometer testing at 50% relative humidity and 100% normal aircraft landing energy led to significant oxidation of friction layer and friction debris samples obtained from commercially available C/C composite brake material, accompanied by the release of gaseous H2O, CO2, and CO (Penszynska-Bialczyk et al. Read the entire page →
From page 9... ... on aircraft brakes, describe the related standards and test protocols, discuss ways to prevent and mitigate such effects, and identify knowledge gaps. Validity of the Effect of Modern Pavement Deicing Products on Aircraft Brakes Thermal oxidation is the primary design specification governing durability of aircraft C/C composite brakes. Read the entire page →
From page 10... ... Therefore, PDPs play a key role in the trend seen in Table 5. Evidence from aircraft operators and manufacturers in North America, Europe, and Asia corroborate the role of PDPs in catalytic oxidation of C/C composite brakes. Read the entire page →
From page 11... ... Oxidation testing conducted jointly by the Center for Advanced Friction Studies (CAFS) at Southern Illinois University, Dunlop, Aircraft Braking Systems Corporation (ABSC) Read the entire page →
From page 12... ... ( ) FIGURE 6 Selected results from carbon oxidation testing by Center for Advanced Friction Studies (CAFS) Read the entire page →
From page 13... ... As oxidation proceeds, immobile calcium oxide may act as a barrier for additional catalysts, lowering the oxidation rate (Figure 9c) Read the entire page →
From page 14... ... Neither currently contains requirements for C/C catalytic oxidation testing. The SAE G-12 Carbon Oxidation Working Group is in the process of refining a carbon compatibility test protocol with assistance from the SAE A-5A Brake Manufacturers Working Group for inclusion in the next revision of both standards. Read the entire page →
From page 15... ... Materials-deicer compatibility testing conducted by the Concurrent Technologies Corporation on behalf of the Air Force Research Laboratory in 2003 and 2004 included catalytic oxidation testing of four Honeywell C/C friction materials and three pavement deicers that were then new to the market or still in development (Concurrent Technologies Corp. Read the entire page →
From page 16... ... patent was under review for an aqueous liquid aircraft runway deicer composition featuring minimal catalytic oxidation effect on C/C composites. The composition contains 20%–25% w/w of an alkaline earth metal carboxylate, 1%–15% w/w of another alkaline earth metal carboxylate, 1%–35% w/w of an aliphatic alcohol, 0.01%–1% of an alkali metal silicate, and up to about 1% w/w of a triazole (Moles et al. Read the entire page →
From page 17... ... and Scandinavian Airlines System 737-NG and CO EMB-145 MWW (main landing gear wheel well) electrical connectors, MWW components, and air conditioning bay packs. Read the entire page →
From page 18... ... . A majority of the relevant reports involved mechanical and electrical connectors accessible to runway deicers through spraying or splashing, such as main landing gear wheel wells and air conditioning bays. Read the entire page →
From page 19... ... For deicers diluted at 3% by weight or volume (for solid and liquid deicers, respectively) , electrochemical testing of their corrosion to mild steel and galvanized steel showed that the acetates and formates (except the solid analytical KF) Read the entire page →
From page 20... ... The Boeing test protocol uses a 31-day cyclic immersion of Cd-plated steel in the electrolyte, instead of a 24-h continuous immersion used in the ASTM specification. Using this protocol, Cd-plated steel specimens were exposed to eight runway de-icing fluids and three control fluids, with three replicates in each solution. Read the entire page →
From page 21... ... In addition, no testing in relation to C/C catalytic oxidation is known to have been conducted on these formulae. PDPs with low electrical conductivity have been suggested to potentially pose less risk for aircraft components as well as C/C composite brakes. Read the entire page →
From page 22... ... The rest of this section synthesizes the information on the validity and nature of the interaction between modern PDPs and ADAFs, describes the related standards and test protocols, discusses ways to prevent and mitigate such interaction, and identifies pertinent knowledge gaps. Validity of Interaction Between Modern Pavement Deicing Products and Aircraft Deicing/ Anti-Icing Fluids The first glycol-based, non-Newtonian ADAFs were introduced in the early 1960s. Read the entire page →
From page 23... ... It should be noted that the effects of modern PDPs on aircraft components lead to substantial financial consequences such as increased maintenance, inspection, and replacement costs and flight delay costs. Continental Airlines forecasted out-of-service and flight delay losses owing to catalytic oxidation of C/C aircraft brakes starting at $200,000 and $500,000 annually (Duncan 2006) Read the entire page →
From page 24... ... Catalytic oxidation of carbon–carbon composite brakes 1. Academic-peer-reviewed literature 2. Read the entire page →

From page 8...

... As such, thermal oxidation usually will not occur until the anti-oxidant layer is disrupted. Dynamometer testing at 50% relative humidity and 100% normal aircraft landing energy led to significant oxidation of friction layer and friction debris samples obtained from commercially available C/C composite brake material, accompanied by the release of gaseous H2O, CO2, and CO (Penszynska-Bialczyk et al.