On Jul 31, 7:00 am, Stealth Pilot
wrote:
On Wed, 30 Jul 2008 16:14:26 -0700 (PDT), 150flivver



wrote:
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

What an utterly absurd statement! You may not need to use the brakes
to stop but that's what they're there for. On a long enough runway I
may not use the brakes at all but on a short runway, you better
believe the brakes will be needed to stop whether you're flying a 747
or a C-150. Everything is a compromise concerning weight and
capability on an aircraft; aircraft brakes on light aircraft may not
have the stopping power of power disc brakes on a dump truck but both
are designed for "stopping."

one day it is hoped that you will learn something of aircraft design
and good piloting skills.
untill then I suppose you'll just keep plugging away doing the best
you can as a poor pilot.

the brake pads on your aircraft are about 3/4" x 2" in size.
the aircraft weighs 1500lb.

From the Cessna 172M POH, regarding forced landings:
6. Airspeed--65 to 75 MPH (flaps down)
7. Turn off master switch
8. Unlatch cabin doors prior to final approach
9. Land in a slightly tail-low attitude
10. Apply heavy braking while holding full-up elevator.

The Canadian Flight Training Manual, in the Landings section,
mentions braking during rollout several times.

In Canada we have something called the Canadian Runway Friction
Index (formerly the James Brake Index) and it gives approaching pilots
an idea of the runways surface conditions for things like steering and
braking during the landing rollout. I imagine other countries
(including Australia) have a similar scale.

So, it would seem that both the manufacturer and the people
who govern both flight training and international airports expect us
to use the brakes in the landing roll. Strange, huh?

We run six airplanes in flight training service. We find that
the brakes aren't hurt by normal use, even by heavy braking in a short-
field landing. It's the guys who taxi with too much power and hold the
taxi speed down using brake, and do that for 2000' on the taxiway.
That's when they get really hot and the metallic bits in the pads
begin to weld to the discs. Small raised steel burrs on the disc then
chew the pads up.
The pads and discs on a 150, say, are not unusually small for
the weight of the airplane when they're compared to the pads and discs
on the front of my compact car, which grosses three times as much as
the 150 and goes a lot faster on the ground than the 150 does. (The
rear brakes in most cars contribute maybe 20% of total braking and you
might not even miss them if they didn't work.) McCauley, and Cleveland
after them, design light aircraft bakes that are expected to stop
airplanes. If they didn't, someone else would and the manufacturers of
airplanes would buy those better brakes, believe me.

Dan