tigermoth
Posts: 7
Joined: Wed Nov 23, 2005 10:54 pm

QNE, QNH, QFE

Fri Nov 25, 2005 9:51 pm

I know they are altimeter settings but can someone explain what they mean and when they are used? Many thanks
 
Tristarsteve
Posts: 3364
Joined: Tue Nov 22, 2005 11:04 pm

RE: QNE, QNH, QFE

Fri Nov 25, 2005 10:07 pm

QNE Height above sea level at standard setting 1013
QFE Height above airfield
QNH Height above sea level.

Type QNE into google and there is a good description in the third ref.
 
julesmusician
Posts: 378
Joined: Sun Aug 28, 2005 3:25 am

RE: QNE, QNH, QFE

Fri Nov 25, 2005 10:26 pm

Basically the codes were meant to mean:

QFieldElevation
QNauticalHeight
QNauticalEquivalent
African Civil Aviation Commission president "You don't want to fly out as a passenger and come back as cargo."
 
CosmicCruiser
Posts: 2049
Joined: Tue Feb 22, 2005 3:01 am

RE: QNE, QNH, QFE

Fri Nov 25, 2005 11:15 pm

Another gouge that I saw in Professional Pilot magazine many years ago:
Q oceaNHeight
Q Feet above Earth
Q staNdardprEssure
 
PW4084
Posts: 287
Joined: Tue Mar 06, 2001 7:31 pm

RE: QNE, QNH, QFE

Fri Nov 25, 2005 11:39 pm

Here's another way of remembering these:

QNE = EASY, always 29.92

QNH = HARD, as in the ground is very hard... so set your altimeter properly.

QFE = simply field elevation

PW4084
 
tigermoth
Posts: 7
Joined: Wed Nov 23, 2005 10:54 pm

RE: QNE, QNH, QFE

Sat Nov 26, 2005 4:03 pm

Thank you all for your replies. Its not really what each of the Q codes mean that i am unclear about, but solving problems related to Q codes (in ground school) that I cannot seem to understand..for example, how do I go about solving this quiz: (I hope I got it right)

"An a/c is flying at FL85 and is cleared to descend to 3500 feet on QNH 1000, but the pilot finds his altimeter stuck. To what height must he descend?"

Thanks / Tigermoth
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: QNE, QNH, QFE

Sat Nov 26, 2005 6:45 pm

And how will he know, with his altimeter stuck?  Wink

Let us, for the sake of the discussion, assume that it is instead the altimeter setting (Kohlsmann) mechanism which has stuck.

First off, he should descend to a height of 3,500 feet ASL. That is what they tell him to do. How to actually go about this will become a bit tricky though, as he cannot change his altimeter setting which means his altimeter will misread.

1 hPa is approx equal to 30' of altitude.

If you increase the reference pressure (Kohlsmann setting), the difference between your current (lower) ambient pressure and the reference pressure increases. Your indicated altitude increases.

In the example given, you will be flying at an altimeter setting of 1013 when you should have 1000. This means your altimeter will overread by (1013-1000)*30 feet, or 390 feet. Descend to 3500+390=3890 feet of altitude.

Another way to think about it is "altimeter setting down, altitude down". Picture yourself at your intended 3,500 feet at the correct QNH of 1000. How would you get to your actual QNH of 1013? You'd increase QNH - alas, increase the indicated altitude.
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
noelg
Posts: 2313
Joined: Fri Apr 26, 2002 11:39 pm

RE: QNE, QNH, QFE

Mon Nov 28, 2005 6:48 am

Quoting PW4084 (Reply 4):
QNE = EASY, always 29.92

Unless you're anywhere outside of the USA. It's 1013 everywhere else!  Smile

I always remember by:

QNH: QNationalHeight
QFE: QFieldElevation

Warped logic in the NationalHeight but in my mind it means "Not the airfield height, the height of everything else"!  Smile
 
tigermoth
Posts: 7
Joined: Wed Nov 23, 2005 10:54 pm

RE: QNE, QNH, QFE

Mon Nov 28, 2005 9:37 pm

Thank you Fred and Noel for your replies, getting clearer now.

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