...and that's what this post is about. I was listening to my scanner on LGA approach yesterday and today and I heard the planes getting the altimeter for the approach. The altimeter setting was at hightest 30.55". Isn't that high? I've never even heard it past about 30.25 or so, and I thought for a minute that it was a squawk or something when the pilots were saying "three zero five five, roger".
Does anyone here know the extremes for the barometer that have been documented?
QNH is notation describing the altitude above sea level as opposed to QFE which is the altitude above the ground at the reporting station.
It has nothing to do with Mountains. 18,000 ASL is the transition altitude to standard altimeter setting in North America. Aircraft set the altimeter to 29.92 above this altitude. The transition altitude is different in other parts of the world.