Mikehotel152
Let's say you select AB3 and then smoothly disconnect with the toe brakes just after 100kts, or use AB1 and then manually brake, how does one determine the correct brake cooling schedule?
You
cannot unless BTM is installed, as then any way you brake is irrespective as it is measured by temperature monitors which must not be read until 10-15 minutes after landing, after which brake release can occur for the determined time.
Most short haul operators do not have a BTMS and schedule turnarounds which would/could be adversely affected should any brake release requirement be established for XX minutes after 10-15 minutes on block as the turn around time does not allow for this.
The above mentioned operators rely on aircrew to plan ahead and apply correct braking technique reducing brake temperature rises by selection of proper amount of reverse thrust, deployed at the correct time and for the correct duration.
At least, that is thought in training and management, as on the line many pilots have no clue about brake cooling as the matter is never adequately explained, thus who could blame them if a higher ranking (training) crew member tells them "you do not need to use reverse thrust, it has no effect on landing"...
These pilots come onto the line not knowing any better and are a safety hazard for those crew flying AFTER them on the aircraft's next rotation as they leave the aircraft after their (e.g. 4 short sectors of) flying with all landings performed IDLE reverse and AB3, never releasing brakes to cool on stand in their turnarounds...
This threat can only be assessed by the next pilot by feeling the brakes or heat radiating from them. Remember cool to the touch requirement before subsequent departure? If you cannot touch the brake discs, they are probably still too hot between the discs internally at the friction layer.
Alternatively if the side wall of the tire is warm to the touch it must mean that the NOx inside the tire has risen enough to heat a layer of rubber through its entire depth. Caution should then be exercised as rubber is NOT a conductive material, thus these temperatures of NOx must have been significant to heat a layer of rubber.