Acronym QNH
Thread Starter
Join Date: Jan 2009
Location: Hampshire
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
Acronym QNH
Answer please.
This question has always been, for me, like one of those you don't ask the Doctor for fear it might make you look an idiot for not knowing the answer to already.
QNH is an acronym which refers, I believe, to pressure in mbs, but what do these letters actually stand for - Q.N.H. ??
This question has always been, for me, like one of those you don't ask the Doctor for fear it might make you look an idiot for not knowing the answer to already.
QNH is an acronym which refers, I believe, to pressure in mbs, but what do these letters actually stand for - Q.N.H. ??
Join Date: Oct 2009
Location: somerset
Posts: 120
Likes: 0
Received 0 Likes
on
0 Posts
DIA74,
HD is right, it doesn't stand for anything in particular, it comes from a long list of Q codes first used in morse signalling and adopted by various radio agencies etc since. There's a very good summary on wikipedia. Type in 'radio Q codes' in the wiki search and you'll get your answer.
HD is right, it doesn't stand for anything in particular, it comes from a long list of Q codes first used in morse signalling and adopted by various radio agencies etc since. There's a very good summary on wikipedia. Type in 'radio Q codes' in the wiki search and you'll get your answer.
Join Date: Oct 2005
Location: Scotland (Fife)
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
DIA74
Unsure on the Q. I believe this may relate to "Quotation" QNH would then stand for Quotation of Nautical Height, the height above sea level. Similarly, QFE is Field Elevation and the barometric height associated with an airfield.
Last edited by LogieBear; 28th Feb 2010 at 16:52. Reason: Incorrect title
Join Date: Oct 2000
Location: Berkshire, UK
Age: 79
Posts: 8,268
Likes: 0
Received 0 Likes
on
0 Posts
LogieBear..... and QAI, QRM, QRN? This site is useful too:
Ralf D. Kloth DL4TA - List of Q-codes
Ralf D. Kloth DL4TA - List of Q-codes
Join Date: Jan 2007
Location: UK
Posts: 433
Likes: 0
Received 0 Likes
on
0 Posts
It doesn't stand for anything apparently - the term "nautical height" was tagged to it as a means of remembering the difference between QFE / QNH. I've also heard "field elevation" tagged to QFE. They're simply mnemonics rather than abbreviations.
Relevant section from Wikipedia (for what it's worth):
The abbreviation QNH originates from the days when voice modulated radio was often difficult to receive, and communication was done by Morse Code. To avoid the need for long Morse transmissions, many of the most commonly asked questions were incorporated into a Q code. When the operator sent the letter 'Q' it indicated that he had a question to ask. To ask for atmospheric pressure at sea-level (i.e., at zero altitude) the letters 'QNH' would be transmitted. A common mnemonic for QNH is "No Height", (whereas the mnemonic often used for QFE is "Field Elevation").
Relevant section from Wikipedia (for what it's worth):
The abbreviation QNH originates from the days when voice modulated radio was often difficult to receive, and communication was done by Morse Code. To avoid the need for long Morse transmissions, many of the most commonly asked questions were incorporated into a Q code. When the operator sent the letter 'Q' it indicated that he had a question to ask. To ask for atmospheric pressure at sea-level (i.e., at zero altitude) the letters 'QNH' would be transmitted. A common mnemonic for QNH is "No Height", (whereas the mnemonic often used for QFE is "Field Elevation").
Join Date: Oct 2008
Location: Brisbane
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
As others have mentioned it goes back to the morse code days. It means "Question - Natural Height?". The answer would be the atmospheric pressure at sea level for the given time and location. So as an example, if airport x is reporting QNH 1007, then the atmospheric pressure at sea level, at the location of airport x, is 1007mb. The "pressure altitude" of that location can then be calculated with the temperature - which is useful for aircraft performance reasons.
QFE means "Question, Field Elevation?". Similar to QNH in that it is a measure of the air pressure, but setting this on the altimeter sub-scale would make the altimeter read an altitude of 0ft when sitting on the ground at the airfield it relates to. I believe this is more commonly used in the UK.
QFE means "Question, Field Elevation?". Similar to QNH in that it is a measure of the air pressure, but setting this on the altimeter sub-scale would make the altimeter read an altitude of 0ft when sitting on the ground at the airfield it relates to. I believe this is more commonly used in the UK.
Join Date: Oct 2000
Location: Berkshire, UK
Age: 79
Posts: 8,268
Likes: 0
Received 0 Likes
on
0 Posts
"Question Natural height" Strangely,I never had an aircraft say that to me when they didn't get the QNH right!! I think everyone on here knows what QNH means.
So, Robin, what's your interpretation of: QDM, QRM, QRA, QTH, QSK, QSS, QTC..?
So, Robin, what's your interpretation of: QDM, QRM, QRA, QTH, QSK, QSS, QTC..?
Join Date: Apr 2007
Location: egsh
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Pedantic mode on:
An acronym strictly speaking is a pronouncable word derived from the initial letters of a series of words, e.g. "scuba" or "laser".
When a series of initial letters produces something which is not pronouncable, it is an "initialism".
Unless I am much mistaken, you cannot that easily pronounce "QNH". At least, I can't.
So it is an initialism.
Might just stay in pedant mode for a while.
An acronym strictly speaking is a pronouncable word derived from the initial letters of a series of words, e.g. "scuba" or "laser".
When a series of initial letters produces something which is not pronouncable, it is an "initialism".
Unless I am much mistaken, you cannot that easily pronounce "QNH". At least, I can't.
So it is an initialism.
Might just stay in pedant mode for a while.
Pedant Mode ON: QNH refers to an Altitude (amsl), QFE refers to a Height above a specified datum (eg. airfield/touchdown elevation). It therefore looks as if "Nautical Height" was an attempt at some form of mnemonic which only served to confuse the issue further!
Pedant mode OFF.
FZ
S.O.D.C.A.T.
Pedant mode OFF.
FZ
S.O.D.C.A.T.
Join Date: Oct 2000
Location: Berkshire, UK
Age: 79
Posts: 8,268
Likes: 0
Received 0 Likes
on
0 Posts
<<QNH refers to an Altitude (amsl), QFE refers to a Height above a specified datum >>
Not strictly correct. Both refer to altimeter settings which produce certain altitude/height readings. Very basically, if the QNH is set on an altimeter it reads aerodrome elevation, ie distance above sea level. Set QFE on an altimeter and it reads 0 (zero) on the airfield, although on some hilly airfields different QFE readings may be produced for different runways. There is a lot of good information here:
Altimetry in general explained | IVAO Academy
Not strictly correct. Both refer to altimeter settings which produce certain altitude/height readings. Very basically, if the QNH is set on an altimeter it reads aerodrome elevation, ie distance above sea level. Set QFE on an altimeter and it reads 0 (zero) on the airfield, although on some hilly airfields different QFE readings may be produced for different runways. There is a lot of good information here:
Altimetry in general explained | IVAO Academy
Supercharged PPRuNer
Join Date: Nov 2000
Location: Doon the watter, a million miles from the sandpit.
Posts: 1,183
Received 0 Likes
on
0 Posts
And to quote my ATPL General Nav instructor (the legendary Baz):
“Q codes were invented by the military during the war to confuse the enemy, and they’ve been confusing the f*** out of pilots ever since.”
“Q codes were invented by the military during the war to confuse the enemy, and they’ve been confusing the f*** out of pilots ever since.”
Join Date: Aug 2008
Location: england
Age: 80
Posts: 24
Likes: 0
Received 0 Likes
on
0 Posts
re QNH
QNH Nautical Height is Height, or level, above sea level, at mean tide (ASL) as in Hypsography using a levelling rod as in land surveying, or DGPS. It ia all in the Wiki
There are also 'Z' codes if you really want to confuse yourself.
Ralf D. Kloth DL4TA - List of Z-codes
Not gunna mention the Falcon codes, oops already did!
Regards,
BH
Ralf D. Kloth DL4TA - List of Z-codes
Not gunna mention the Falcon codes, oops already did!
Regards,
BH