Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!munnari.oz.au!uniwa!cc.curtin.edu.au!tcliftonr
From: tcliftonr@cc.curtin.edu.au
Newsgroups: rec.skydiving
Subject: Re: High altitude landings
Message-ID: <1991May30.154444.8516@cc.curtin.edu.au>
Date: 30 May 91 07:44:43 GMT
References: <13377@exodus.Eng.Sun.COM> <2020017@hpfelg.HP.COM>
Organization: Curtin University of Technology
Lines: 18

In article <2020017@hpfelg.HP.COM>, larry@hpfelg.HP.COM (Larry Chapman X3117) writes:
> 
> From  personal  experience,  I don't  believe  the 20% numbers  you've been
> getting.  The  difference  between a sea  level  landing  and a landing  at
> 9,500' is very significant.
> 

Well, 20% is 20% more momentum and 44% more kinetic energy.  Pretty significant.

But yes there may be other factors.

For one, there is the effect of viscosity, which decreases strongly with 
decreasing temperature.  In the cold, that should increase the circulation 
around the airfoil so that lift increases, but should worsen the wingtip 
vortexes (ices?) so increasing drag there.  Is anyone familiar with the 
theory of airfoils vs viscosity?

  Roger Clifton.