Hans,

Just one small correction to your post. TAS is the actual speed you are
traveling through the air. Ground Speed (GS) is the speed you are relative
to the surface. Wind is what make TAS and GS different.

Respectfully,

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder

"Hans Holbein" wrote in message
...
HEMI - Powered schrieb:

Im no pilot neither.

Im still learning all the things needed to go online for combat with
other weirdos. ;-)

The usual airspeed indicator is a tube on some undisturbed place at the
aircraft, the pitot-tube.
With lesser air pressure at increasing height you need more speed to
induce the pressure in this tube to indacate the airspeed.
So indacated airspeed IAS differs from true airspeed TAS which means the
speed realtively to the surface.
With no wind influence, as I recall the fomula is
TAS=IASx(1+ Heightx0,02/300)
But I might have forgotten something.
Its ~8% pus in 3000ft and ~44% in 20000ft
If I'm correct, in 20000ft you fly 540knots while your indicator shows
only 375knots.

Im not very comfortable with the anglo-saxon systems, but over a long
term I think the metric system will do the race.
Resistance is futile!
SCNR