Increasing power required with altitude.. what's a good plain english explanation?

On Fri, 02 Feb 2007 11:51:34 GMT, "xerj" wrote:

I was trying to explain to a non-pilot why increased power is required with

Increased power is not needed and not normally obtainable at higher
altitude with a normally aspirated engine. It takes less power to
maintain speed at altitude compared to lower. If you just maintain
power you go faster than you do down lower.

altitude. She said "isn't the air thinner up there so there isn't as much
resistance?" I said "yes, but the plane needs to fly fast enough for the air
over the wings to feel like it does down low. So the speed required goes up
you get higher. More speed need more power."

This didn't really do the trick.

Can someone think of a better way of putting it without resorting to
mathematics and an explanation of IAS and TAS?

"I think" you are confusing the difference between IAS and TAS at
altitude versus power at altitude, or as Dennis already suggested,
throttle position compared to power.


TIA

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com