ABS - or is it Pure BS

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Tue Apr 6 07:44:19 1999

> >It's so they come to a stop. How else would you bring a 747 at 400,000
> >pounds from 140+knots to 0 in less than 7000 feet!
>
> So, why do you need ABS if you are just landing straight?

Two reasons. One so you do land straight. The other is more imporant,
Stopping a large plane requires a lot of breaking all done hydraulically
with power assist, teh pilot has little feel for those tires down on the
ground. To stop in the shortest distance the wheels have to be brought
to a near stop without actually stopping them. If they stop turning the
rubber peels off and forms little rollers under the tires thereby reducing
the effictive friction to near zero. That must not happen. Even on my
little 1600 pound cessna if the tires lock they skid and it will actually
take more distance to stop, that is also neverminding that skidding
removes rubber at a ferocious rate and can cause tire loss, gear collapse,
or worse fires(on bigger birds).

The ABS on card were designed for the same purpose, to nearly stop the
wheel to prevent skidding.
 
Allison
Received on Tue Apr 06 1999 - 07:44:19 BST