Hi gravity32,
Have you considered the lag between the time of the pressure felt at the static port, and the delay taken as the pressure wave moves along the length of the narrow plumbing to the pressure transducer (which generates the altitude signal) with the rate of descent? The Rad Alt suffers no lag.
Edit. (The lag is the reason why they developed Instantaneous / Inertial VSIs.) What altitude difference would 1 second make at the recorded ROD?
Last edited by rudderrudderrat; 16th Sep 2011 at 11:34.