PJ2, I agree, the relay and radio altimiter didn't cause those two crashes, the pilots did. Their backup failed in both cases letting their mistakes go unnoticed. Pilots should not expect automatic warnings to correct their mistakes. As previously stated always do a final check mentally on take off and landing of the two or three things that matter most. Flaps, trim on takeoff and gear, flaps and spoilers armed for us for landing. We lost one due to spoilers not being armed along with other things so added that.