Re: Wing "flaps" that raise on landing

From:         drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard)
Organization: Boeing
Date:         06 Feb 93 02:45:32 PST
References:   1
Followups:    1
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In article <airliners.1993.118@ohare.Chicago.COM> pshuang@athena.mit.edu (Ping Huang) writes:
>When a jetliner lands, usually flaps on the wings are raised. Is the
>primary braking effect from the additional air resistance, or from the
>fact that the airplane is also pushed downward and therefore the brakes
>on the landing wheels exert more friction against the runway?

Actually, it is the spoilers that are raised.  Called "lift dumpers" on
some European designs, they do indeed give the airplanes brakes a boost by
increasing the normal force on the tires.  The flaps are kept fully
deployed until the airplane exits the runway I think.  Every little bit of
drag helps. :-)


-- 
Terry
drinkard@bcstec.boeing.com
"Anyone who thinks they can hold the company responsible for what I say has
more lawyers than sense."