Re: Gear up on go-around?

From:         rdd@cactus.org (Robert Dorsett)
Organization: Capital Area Central Texas UNIX Society, Austin, Tx
Date:         26 Feb 93 04:43:31 PST
References:   1
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In article <airliners.1993.189@ohare.Chicago.COM> you write:
>Is it necessary to raise the landing gear when aborting an approach and going
>around? 

Yes.

>Why or why not?

To use the immortal words of a recent poster, gear lends a "crapload of
drag."  :-) 

Lift is a function of excess power: this in turn is a function of
power available and power required.  Power required, in turn, is the 
amount needed to overcome drag in a specified flight condition.  Thus, 
any in excess results in *lift*.

So, if you reduce drag, you lessen power required, and increase lift.  It's 
that simple: your objective in this game is to get away from the ground as 
fast as you can, as soon as you decide you won't be landing on it.  So you
retract your gear.  See Don Webster's recent post for a detailed overview
of a 747 go-around procedure. 

A pilot also considers, in the back of his mind, what might happen should he
lose an engine, in which case he can very easily lose a lot of that excess 
power.  You don't want to be wallowing around like a hog in mud when this 
happens.  And, as the old saying goes, altitude == speed (potential energy),
and speed == life.  Being low, slow, and dirty is a good way to kill your 
airplane, and maybe your passengers, as the captain of an A320 discovered in 
France in 1988.  So any competent pilot keeps his margins, and, indeed, all
of airline operations and training is based on the assumption that sh*t 
happens, and *will* happen.

The best "lay" explanation of these concepts I've seen is in _The Illustrated
Guide to Aerodynamics_.  It's pretty pointless to discuss this further 
without some sort of graphing capability. :-)

Posters are requested to follow up to rec.aviation.piloting.


---
Robert Dorsett
rdd@cactus.org
...cs.utexas.edu!cactus.org!rdd