PPRuNe Forums - QNH 999 hPa?

Quote:

Originally Posted by Gonzo (Post 10600158)

To my knowledge PANS ATM does not mandate the inclusion of the unit being used in the RTF message.......

See the above, and:

DOC 9432 - 3.1.3:

"The following words may be omitted from transmissions provided that no confusion or ambiguity will result:

d) “HECTOPASCALS” when giving pressure settings."

I think that should settle it.

So in my opinion, since US pilots have a nasty tendency of abbreviating pressure settings, putting "hectopascal" after the QNH when below 1000, is meeting the requirement in DOC 9432, when handling US registrered aircraft, or in doubt.