My ALTRAK is a wonderful piece of hardware and when I punch the ALT button it probably holds altitude within + 20 feet. I see the vertical speed needle vary up and down around "0" when flying in this mode which is a digital reaction to pressure deviations I'm sure. The question is, is the distance from point A to point B actually longer in this mode than a hand flying mode where the plane is allowed to "go with the flow."
Bob Axsom
Bob Axsom