Mac's ASD story on partial braking caused by feet inadvertently too high on the pedals reminds me of a couple of stories. The Boeing 737 pilot training manual 1976 edition had this to say:
Braking Technique
"For normal usage, the pilot's heels should be on the floor. Just before landing place your feet on the instep bar of the brake pedal with toes away from the brake pedals, so that the brakes may be applied without delay as soon as the wheels are on the ground, either to initiate manual braking or to override the autobrakes as required."
That advice was a real trap as the pilot had to not only place his feet higher than normal on the rudder pedals just before touch down, but also to bend his toes upwards in his shoe to avoid depressing the top part of the brake pedal while applying rudder control with his heels. It was on crosswind landings where rudder was needed and inadvertent brake use was common. Boeing later removed that advice from later editions of the flight crew training manual, thank goodness.
Also, on more than one occasion in the 737 flight simulator, it was noticed that some pilots under training inadvertently applied brake pedal pressure during the take off run. In a dark cockpit it is impossible to see someone's toes applying brake pressure. However the simulator instructor station depicts on a screen a brake pressure gauge for each wheel brake from zero brake pressure to 3000 PSI.
During the take off run, inadvertent brake pedal pressure by a pilot is easily seen with the brake pressure gauge on the instructor panel oscillating from no brake pressure to 200 PSI and sometimes 500PSI. The pilot is usually quite unaware that he is inadvertently touching the top of the rudder pedal with his toes - enough to apply brake pressure. Of course the slower acceleration invalidates the calculation of V1 as well as causing heat build up in the brakes.
During one 737 training session with two Asian cadet first officers, the instructor told the PF he was using the brakes during the take off roll since he (the instructor) could see the brake pressures fluctuating on the instructor display. The student flatly denied using the brakes. This was a classic example of denial and loss of face. So for the next take off, the instructor invited the other cadet to sit on the instructors seat while his compatriot did another take off. Sure enough, the brake pressure gauge on the instructor panel revealed without a shadow of doubt that the pilot was inadvertently applying intermittent brake pedal pressure on his rudder pedals. The cadet observing the instructor screen saw this happening and in his own native language explained to his sim buddy what he was doing. That left one recalcitrant cadet somewhat red-faced and the instructor smiling in quiet satisfaction.
