Greetings
HUD gets its information from the IRS, so it is Earth related, wereas pitch is Air related.
ALPHA:Also α, also angle of attack, the angle between the relative wind and the longitudinal axis of the body, x-z plane, deg.
In other words the flight path vector shows you where you are going
Angle zero, could be in a windshear 
Last edited by kijangnim; 5th May 2010 at 19:07.