Originally Posted by
atpcliff
Best way to keep the brakes from overheating in a heavyweight 747-8 landing, long runway:
I think that Flaps 30, and Max Reverse are commonly accepted.
We were told minimal braking is best, so that means Autobrakes 2. But, an FO I was talking to said a DE told him that Autobrakes 4 is cooler, because the brakes are applied for a lessor time period, than Autobrakes 2. Another DE told me that AB3 is the best.
That DE who said "Autobrakes 4 is cooler" needs to get his head examined. The harder the brakes are applied, the more power (i.e., energy dissipation/time) used and the less influence of other factors like air drag, reverse thrust, and mechanical friction. Therefore, Autobrakes 2 and max reverse thrust will cause the least wear.
Autobrakes 1 is not used in the 744/748 because it usually results in multiple brake-release cycles during the landing roll, which increase the wear on carbon brakes. Any time you think Autobrakes 1 might be sufficient (e.g., CVG Rwy 9), simply use idle reverse and Autobrakes OFF instead. On that runway, do a brake check crossing 18R/36L and roll to the end using hardly any brakes at all.