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From: robs@tektools.UUCP (Robert Sleator)
Newsgroups: net.aviation
Subject: Re: spoilers/airbrakes
Message-ID: <695@tektools.UUCP>
Date: Sun, 26-Jan-86 05:21:13 EST
Article-I.D.: tektools.695
Posted: Sun Jan 26 05:21:13 1986
Date-Received: Tue, 28-Jan-86 05:37:00 EST
References: <5@petrus.UUCP>
Distribution: net
Organization: Tektronix, Inc., Beaverton, OR
Lines: 20


A sailplane has spoilers to control its glide path.  (Some sailplanes 
have 90 degree flaps or drogue chutes instead of spoilers.) Maximum 
glide ratios on production sailplanes range from around 23:1 up to one 
with a measured 60:1 (the Nimbus 3).  A sailplane pilot usually flies 
the pattern with around half spoilers, adjusting them as needed to hit 
the runway at the desired spot.  Without spoilers, you would have to 
rely on slipping or rearranging your pattern to put the plane
down at the intended point.  And remember, you don't have the option 
of going around again.  Without glide path control, a slight 
miscalculation at 60:1 and you could wave to your friends on the field
as you made a low pass over the runway and flew into the trees at the 
far end.

A power pilot can achieve the same effect as spoilers by adjusting 
the throttle.  With engine idling, I think most single engine planes 
have glide ratios of less than 10:1.

Robert Sleator
tektronix!tektools!robs