For the go-around call to be made at 500 Radio Altitude, it would imply that you have had a precision approach terrain chart drawn up for that approach and examined it. There are several approaches where 500 RA is relatively meaningless in terms of being 500 feet above threshold (or touchdown zone) elevation. Please remember that very very few runways are ever surveyed for the PATC which is a great shame as radioaltimeters can be used to very beneficial effect with some ALAR procedures.
Discount