sure, i do agree. but who can guarantee gps reliability as long as the military has control over it. but on the subject, does the 777 ADIRU fast realignment cancel out all accumulated errors? of course all drift and position errors are reset, but what about the gyro errors. if a fast alignment is as good as a full one, why should we do one after all. i was tracking the irs-fmc deviation on the POS REF page, and could not proof any accuracy improofments with full alignments, even though i wanted to proof just that.