On 24 Apr 2004 16:09:14 GMT, Stan Gosnell wrote:

Matt Whiting wrote in
:

Seems like it would have to have an internal compass or some other
source of heading information to do this trick.

It has to know your heading and airspeed. Knowing this, calculating the
wind is trivial. Most boxes require the pilot to input this information,
because the normal airspeed and heading indicators don't have electric
output. With new glass cockpits, this information becomes available to the
boxes.

There's no input for either. I'd guess for holding patterns it's able to
make computations based on known GS and track; and probably it assumes a
constant airspeed.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)