Re: Braking

Date:         23 May 97 09:03:30 
From:         "S. Buining" <>
Organization: Delft University of Technology
References:   1 2 3
Followups:    1 2
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Matthew Willshee wrote:
> On 9 May 1997, dzul wrote:
> ><snip air v. wheel brakes arguments>
> >
> > if the wheel brakes gets too hot (if u do not use the reverse thrust), u need
> > a lot of time to cool them off.

> One bit I found especially interesting was a part of the flight test
> programme that involved braking from V1 (I think) to a standstill using
> wheel brakes with the engines at full power.  There was a minimum time
> limit that the plane then had to stand (the brakes glowing red hot)
> without the undercarriage catching fire.

Another interesting item about the braking is the fact that the brakes
can get pretty hot, but letting them cool down often does not require
replacement. Due to the temperature rise, the tires will expand (due to
internal pressure increase) and if the pressure gets to high, a pressure
fuse will blow, letting the tire run empty. This is to prevent a tire
burst (which can have pretty nasty consequences).
Once i read an article in a newspaper where the author didn't exactly
understand how this worked. He/she wrote: 'During a rejected take-off of
an MD-11, the pilot, as a precaution, let the tires run empty....' I am
still wondering where in the cockpit i can find the button to do so!?

Michiel van der Eijk