Well, that "may" be true for certified aircraft. But with a homebuilt,
all bets are off. The builder is free to overpower his brake system
however he sees fit. And put large and powerful enough brakes on it to
provide plenty of energy absorbing power to stop his aircraft. Even
airliners have definite limits on their brakes. You take off heavy and
abort above 100 knots, and you are most certainly going to be in the
"melt zone". wherby the fuse plugs will melt and deflate the tires by
design. So your statement can't be a blanket statement about all
aircrat. Depends on the aircrafts weight at takeoff or landing. the
speed at which the brakes are applied to bring the aircraft to a stop.
It's all about engery, which is variable for each instance. So even
large aircraft have limits to their stopping power. They'll stop the
aircraft at just about any weight, but over a certain amount, and you
better not stand too close to it after landing.
Plus, way back when, old light aircraft had crap for brakes. Back when
Stinsons, Swifts, and other postwar aircraft were built, there were no
Cleveland brakes. With those, and clones of them, you can stop just
fine.




On Sat, 19 Jul 2008 18:54:27 +0800, Stealth Pilot
wrote:


some interesting points came out of one guy's query re servicing some
old brake master cylinders.

gringomasloco commented regarding broken brake lines spraying brake
fluid over hot calipers and setting the wheels on fire. hmmmmm.

I am talking about light private aircraft here...

as I put it in the subject line aircraft brakes were never designed
for stopping aircraft. they were designed to hold aircraft.
now that may sound like semantic nonsense but it is true.

aircraft brakes were designed for use in holding the aircraft still
while the engine was started. after the taxy out and the engine has
warmed you do a run up check to make sure that the magneto circuits
are up to the bit of work that lies ahead for them. the brakes are
applied to hold the aircraft while the revs are bought up and each
maggy checked in turn.

from a design aspect that is the end of the use of a light aircraft's
brakes until after landing and we wish to hold the aircraft still for
shutdown and disembarkation.

of course brakes are brakes and people will use them like they were
driving cars. light aircraft brakes were never designed for slowing an
aircraft when landing.
I know that they get used for that by students of bad piloting
technique but the design intent is a fact borne out by their
diminutive size.

I'll give one concrete example. The Stinson 108 is a huge aircraft, 4
seats in 1940's luxury, yet it only has brake pucks the same size as a
5.00x5 cleveland. in fact on the one Chris M-F ownes the brakes *are*
cleveland 5.00x5 calipers.

it is quite ok to be masters of the world and fly however you like.
you'll just wear out your aeroplanes faster.

just remember though that aircraft brakes are for holding the aircraft
not stopping it.

now brakes for commercial aircraft are different and they *are* used
for stopping, but the brakes on little lighties arent.
some people have yet to realise that.

Stealth Pilot