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Old 23rd March 2025 | 01:27
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172_driver
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Joined: Jan 2006
: CPL
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From: Between a rock and a hard place
Reducing the number of applications is a well established fact for carbon brakes. In addition to that, temperature matters.I recently read an Airbus article about carbon brake wear optimization with graphs for three different manufacturers (Messier-Bugatti, Goodrich, Honeywell), brake wear as a function of temperature, and they all look different. This is a cut out from the article, not necessairly very useful for the average line pilot (who hasn't got a clue which brake manufacturer is installed...) but shows there is no one size fits all approach.

4.2 To Optimize Brake Temperature

As demonstrated in Figure 1, the typical spectrum of carbon wear, versus carbon-disc temperature, illustrates how low-wear and high-wear vary with the disc temperatures. Therefore, operational recommendations to increase carbon brake life should aim to keep the carbon temperature outside the high-wear range. In order to increase carbon-brake life, the brakes should be operated in general when either cold or hot, but not at intermediate, warm temperatures. Pilots should receive simple instructions on brake operation, based on the average optimum temperature ranges for low carbon wear and in accordance with operational constraints. For example, based on data provided in Figure 1:
- For Messier-Bugatti brakes the pilot should receive instructions to taxi with an indicated brake temperature below 80 °C, or above 250 °C.
- For Honeywell-ALS brakes, the indicated temperature should be below 150 °C, or above 315 °C.
- For UTAS brakes, the indicated temperature should be significantly below 80 °C, or above 250 °C. These instructions must correspond to the specific brake type of the aircraft, and to the specific operating conditions. This is because, as demonstrated in Figure 1, the relationship between carbon wear and approximate brake temperature varies significantly between different brake types.
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