PPRuNe Forums - View Single Post - ICAO Altimeter
Thread: ICAO Altimeter
View Single Post
Old 2nd Aug 2012, 08:45
  #1 (permalink)  
Join Date: Oct 2010
Location: France
Posts: 290
ICAO Altimeter

I've passed my ATPL(A) and I'm now training (part time, as aviation is just a hobby) for CPL(A).

I've read ICAO DOC 7488, but I have not found answers to the following questions.
- What accuracy is required for an altimeter? Where is it officially documented?
- I suppose that the setting knob of an altimeter is linear, ie that the altitude indication variation rate is 27.31ft/hPa whatever the altitude reading is. Where is this officially documented?
- What is the official definition of QNH, and where is it officially documented? I assume that the only good definition of QNH would be, the altimeter setting that would make an ideal ICAO altimeter read the altitude of the ARP (or RWY Threshold).
I've tried to search the forum with "27.31" but it does not work. May be there's a trick I don't know about to do a search for numbers.

172510 is offline