September 6th 16, 05:57 PM
On Friday, October 29, 1999 at 12:00:00 AM UTC-7, Mark Kolber wrote:
> jcrogin > wrote [snip]:
>
> > I mean, cold air is more dense than hot air. So if
> >you fly from hot to cold, why doesn't your altimeter think you're
> >flying lower, rather than higher? What am I missing?
>
> I've gotten this one wrong a million times until I read this
> (highly simplified) explanation in a magazine:
>
> Imagine your airplane riding on top of a cylinder of air.The cylinder
> sits on the ground and its sides are rigid, but it's capable of
> expanding vertically.
>
> In general, when air (or any gas) warms, it's volume increases. When
> it cools, its volume decreases. What effect will that have on the
> cylinder your plane is riding on?
>
> Works the same for low pressure -- generally, low pressure means less
> weight -- more expansion -- more volume.
>
> =======================================
> ______|______ Mark Kolber
> \(o)/ Denver, Colorado
> o O o www.midlifeflight.com
> =======================================
> replace "spamaway" with "mlf" for email
Than you for this!!!!!
> jcrogin > wrote [snip]:
>
> > I mean, cold air is more dense than hot air. So if
> >you fly from hot to cold, why doesn't your altimeter think you're
> >flying lower, rather than higher? What am I missing?
>
> I've gotten this one wrong a million times until I read this
> (highly simplified) explanation in a magazine:
>
> Imagine your airplane riding on top of a cylinder of air.The cylinder
> sits on the ground and its sides are rigid, but it's capable of
> expanding vertically.
>
> In general, when air (or any gas) warms, it's volume increases. When
> it cools, its volume decreases. What effect will that have on the
> cylinder your plane is riding on?
>
> Works the same for low pressure -- generally, low pressure means less
> weight -- more expansion -- more volume.
>
> =======================================
> ______|______ Mark Kolber
> \(o)/ Denver, Colorado
> o O o www.midlifeflight.com
> =======================================
> replace "spamaway" with "mlf" for email
Than you for this!!!!!