altimeter setting
)
Joined: Sep 2012
Posts: 160
Likes: 0
From: London
Do I get it right?
OK, I'll tell everyone what I've understood. Unlike QNH and QFE which are altimeter settings, QNE is an altimeter reading - it is an indication on your altimeter at landing when you set it to 1013.2/29.92. Of course it is as changeable as QNH and QFE, so you need to get it each time from someone. And then, when landing:
To answer a question from Crash one I'll now put my Math MSc hat on:
You just missed brackets 
/h88
- instead of setting QNH on alt and reading THR elev when you land, and
- instead of setting QFE on alt and reading 0 when you land,
- you set standard setting 1013.2 and read QNE when you land.
To answer a question from Crash one I'll now put my Math MSc hat on:
- I just derived on the back of an envelope that QNE = (1013.2 - QFE) x 30, but:
- QFE = QNH - (elevation/30), so:
- QNE = (1013.2 - QNH) x 30 + elevation
You just missed brackets /h88
Joined: Sep 2006
Posts: 1,434
Likes: 0
From: Scotland
Thank you I did remember the brackets but too late. Must try harder !!
Therefore: Leuchars QNH at this time is 958hectobars. If I were to land at Kingsmuir, elevation 398 ft altimeter should read 2114ft (using what should have been QNH) ?
Therefore: Leuchars QNH at this time is 958hectobars. If I were to land at Kingsmuir, elevation 398 ft altimeter should read 2114ft (using what should have been QNH) ?
Joined: Jul 2004
Posts: 1,901
Likes: 1
From: On the wireless...
Please refer to CAP493 Annex A Page 2.
Crash one, you would need to obtain/calculate/deduce a QFE for Kingsmuir. If using the Leuchars QNH then the Kingsmuir QFE might be approximately 14 hPa lower, ie. approximately 944 hPa, and possibly off the subscale. From the table QFE 944 hPa gives a QNE of 1946 ft, ie. the altimeter would indicate approximately 1946 ft on landing.
Correct.
Dave, a QNE is not a pressure setting. If you are the Dave Wilson I trained at Farnborough in the early eighties you have since become a very experienced GA pilot, so should therefore know this!
Crash one, you would need to obtain/calculate/deduce a QFE for Kingsmuir. If using the Leuchars QNH then the Kingsmuir QFE might be approximately 14 hPa lower, ie. approximately 944 hPa, and possibly off the subscale. From the table QFE 944 hPa gives a QNE of 1946 ft, ie. the altimeter would indicate approximately 1946 ft on landing.
Originally Posted by hegemon88
OK, I'll tell everyone what I've understood. Unlike QNH and QFE which are altimeter settings, QNE is an altimeter reading - it is an indication on your altimeter at landing when you set it to 1013.2/29.92. Of course it is as changeable as QNH and QFE, so you need to get it each time from someone. And then, when landing:
instead of setting QNH on alt and reading THR elev when you land, and
instead of setting QFE on alt and reading 0 when you land,
you set standard setting 1013.2 and read QNE when you land.
Did I get it right?
instead of setting QNH on alt and reading THR elev when you land, and
instead of setting QFE on alt and reading 0 when you land,
you set standard setting 1013.2 and read QNE when you land.
Did I get it right?
Dave, a QNE is not a pressure setting. If you are the Dave Wilson I trained at Farnborough in the early eighties you have since become a very experienced GA pilot, so should therefore know this!
Joined: Oct 2013
Posts: 217
Likes: 0
From: UK
That's the second time in about an hour I've been mistaken for someone else in two different threads! I'm Dave Wilson of no fame whatsoever. It's a very common name believe it or not. In fact my full name is David John Wilson and there was anothe DJW of the same rank on 3Sqdn when I was there. Caused no amount of hilarity. The chap on the other thread thinks I am one Whizz Wilson of Australia.
Me. Not to be confused with more famous Dave Wilsons.
So if I'm asked to set QNE when flying IFR exactly what pressure setting do I set on the subscale? Have I been flying at the wrong FL all this time?
Me. Not to be confused with more famous Dave Wilsons.
So if I'm asked to set QNE when flying IFR exactly what pressure setting do I set on the subscale? Have I been flying at the wrong FL all this time?
Joined: Jul 2004
Posts: 1,901
Likes: 1
From: On the wireless...
Mis-ident. Us ATCOs do that occasionally. Use full callsign.
Anyway, he was better-looking than you. Probably because of that sprout soup, it doesn't look very appetising.
1013.2 hPa. It's not a QNH, not a QFE, nor a QNE. it's SPS.
Greetings to all in Season.
Anyway, he was better-looking than you. Probably because of that sprout soup, it doesn't look very appetising.
1013.2 hPa. It's not a QNH, not a QFE, nor a QNE. it's SPS.
Greetings to all in Season.
Joined: Oct 2013
Posts: 217
Likes: 0
From: UK
At risk of sounding stupid, no I'll rephrase, sounding stupid, exactly what is QNE? I've been flying all of this time, IFR and VFR and not known what it is. Methinks there was a gap in my training somewhere.
Joined: Jul 2004
Posts: 1,901
Likes: 1
From: On the wireless...
From CAP413:
Clocks off…
QNE is the indication which the altimeter will give on landing, at a particular time and place, when the hectopascal scale is set to 1013.2 hPa.
QNE information may be used by pilots of aircraft whose altimeters cannot be set to below 950 hPa.
The QFE/QNE conversion will be calculated by ATC.
QNE information may be used by pilots of aircraft whose altimeters cannot be set to below 950 hPa.
The QFE/QNE conversion will be calculated by ATC.
Clocks off…
Joined: Oct 2013
Posts: 217
Likes: 0
From: UK
Ah, got it now. I thought you were saying QNE wasn't 1013.25.
I know it's not, I know what you mean by it's not 1013.25. But it is in the backwards way I'm looking at it. We are all clear now, just a syntax problem.
It's actually snails in garlic during a visit to Le Touquet earlier this year. Wouldn't recommend but tick in the box and all that.
I know it's not, I know what you mean by it's not 1013.25. But it is in the backwards way I'm looking at it. We are all clear now, just a syntax problem.
Probably because of that sprout soup, it doesn't look very appetising.
Joined: Feb 2003
Posts: 2,042
Likes: 0
From: Oxford
I once had the altimeter knob come off on approach to Oxford - I got the ATIS, found I couldn't set the QNH (I'd been on regional pressure so quite a few mB different), switched to Approach, informed them, and could hear quite clearly even from 10 miles or so out the scratching of heads as they tried to work out the circuit indicated altitude I should fly to put me at 1200ft QNH.
To be fair to them, it only took them about 30 seconds to come back with an answer which I think was correct (seemed to work, anyway!).
To be fair to them, it only took them about 30 seconds to come back with an answer which I think was correct (seemed to work, anyway!).
Joined: Oct 2013
Posts: 217
Likes: 0
From: UK
The other thing to watch out for is taking off from a high airfield underneath airspace with QFE set. Crosland Moor at Huddersfield is a good one for that, there's class A at 3,500 and class D at 3,000. Field is at 800 odd feet, easy to forget on the climb out, seen it happen.
Joined: Jun 2001
Posts: 3,991
Likes: 8
From: UK
Yes the formula is h=96T/P where h is foot per mb, T is Absolute Temp (deg C + 273) and P is pressure in mb.
However to work out QNE imagine you are on ground at an airport which is 1,000 ft amsl and the QNH is 963 mb so with 963 set the altimeter indicates 1,000 ft Now set 1013 - you are winding on 50 mb = 50 X 27.3 = 1365 ft The altimeter now reads 1,000+1365 = 2365 ft so this is QNE.
I stand to be corrected on this one but although the height change per mb changes with temp and pressure the change in indicated altitude will be the same for a given change in sub scale setting at different altitudes.
However to work out QNE imagine you are on ground at an airport which is 1,000 ft amsl and the QNH is 963 mb so with 963 set the altimeter indicates 1,000 ft Now set 1013 - you are winding on 50 mb = 50 X 27.3 = 1365 ft The altimeter now reads 1,000+1365 = 2365 ft so this is QNE.
I stand to be corrected on this one but although the height change per mb changes with temp and pressure the change in indicated altitude will be the same for a given change in sub scale setting at different altitudes.
Joined: Jan 1999
Posts: 1,377
Likes: 174
From: England
The other thing to watch out for is taking off from a high airfield underneath airspace with QFE set. Crosland Moor at Huddersfield is a good one for that, there's class A at 3,500 and class D at 3,000. Field is at 800 odd feet, easy to forget on the climb out, seen it happen.