Originally Posted by
hawjl
Hi everyone, a recent debate in my company has centered around the proper setting for DA. Some argue that it should match the exact value shown on the Jeppesen approach chart, such as '214 ft,' while others believe it should be rounded up to the nearest increment, like '220 ft.' Which approach should be considered the standard? I've reviewed materials from the FAA, ICAO, and Jeppesen but couldn't find any guidance addressing this specific question. Perhaps it's not an issue that requires much attention, but I'd love to hear your thoughts!
In China you need to follow the NAIP. I understand your question links to international operation, but there is some nice news to you: (TLDR - it does matter).
Because setting a precise number such as 213 is somewhat meaningless, some other providers (different from Jeppesen) round up to the next whole 10'. Lufthansa Systems NAV definitely, for their LIDO charting product. Many huge airlines have flown with those charts long decades using this solution and never had a problem worth rediscovering the wheel.
Second, compare a NAIP chart with DA in feet to a Jeppesen Chart for one of the domestic airports. You will see the CAAC also rounds the number to whole 10' - but somewhat surprisingly - NAIP round numerically, down or up! E.g. the DA of 213 is printed in NAIP as 210 while Jeppesen references 213 (and where LIDO charts would have 220).
So, clear as mud! Happy Spring Festival and stay safe in the busy weeks.