Couple of things. First, bear in mind that in the A320, there are different carbon brakes manufacturers. They all make their brakes slightly different, so their composition, and hence their cooling qualities differ slightly. This is particularly noticeable with the BF Goodrich brakes, if I'm not mistaken.
Second: Again in the A320, the FCOM states that the brakes do cool off faster with the parking brake off, and it advises you to do so if operationally viable. Not only that, but it also states that this action also prevents exposing critical surfaces to higher temperatures thus preventing possible damage, or at least, faster degradation of these components due to heat.
And while we're talking about degradation, since (again) the brake manufacturers and their respective brake composition is different, the one action to reduce brake degradation that applies to all brands of brakes is to reduce brake applications. Some of you have discussed temperatures from a braking efficiency point of view, however, Airbus documentation discusses the use of brakes (actions, techniques, temperatures, etc) from a
brake degradation point of view. Outofsynch mentioned 150 - 200°C; if I'm not mistaken, this is the worst temperature range for ANY brake manufacturer as far degradation goes, since the recommendation is to taxi with either cold brakes (below 80) or "warm" brakes (over 300, if memory serves me right). Let's face it, degradation is a far more usable and impactful factor in day to day operations than the low chance of an RTO.
By the way, these are bites of info contained in the link that
FlightDetent has kindly put up for all of us to improve our knowledge.
Follow your SOP
