For what does QNH stand?

['%MAC']

Hi All,
For what does QNH, QFE, QNE actually stand? In my little mind I use the mnemonic device; Q Field Elevation, QN Hydrosphere, and QNE must then from default be standard. And while we are on the subject, how about QDM and QDR? (I wish we used them here in the States.)

[spekesoftly]

The 'Q' code abbreviations date back to the days when the primary means of Air/Ground communication was by morse code.

As far as I am aware, the letters (Q, N, H) etc don't represent specific words.

QDM - a magnetic heading to steer towards the station called.

QDR - the reciprocal of a QDM

QTE - True Bearing

QSY - Change Frequency

There are many more, but only a few remain in common use.

[ETOPS]

And my personal favourite:-

QBB - What is the height of the base of the lowest Cloud?


I've still got the full list somewhere - will try and dig it out

[KitKatPacificuk]

QFD = Queue For Departure

I think this only applies at Elstree!!!

:D :D :D :D

[Freddy Forks]

Try this site;

www.kloth.net

all the codes you'll ever need.

[stevieboy]

QNH stand for "Question Nil Height"

:)

[DeeTee]

I never knew either and always got confused, so I just made up my own definitions.

QNH = Quoted Nautical Height i.e. Nautical being sea level.
QFE = Quoted field elevation i.e height above field
QDM = Quoted direction Magnetic
QDR = Quoted Direction Recipricol

No scientific basis, but It got my head round the ones I was interested in.

Not really answered the question either. Sorry for wasting bandwidth. :)

[HEATHROW DIRECTOR]

QLO = Quick Leg Over

['%MAC']

Thank you all who have posted, you’ve helped the edification of my little brain, and it is overwhelmed with a completely new field, to me previously unnoticed. Perhaps Truman was correct, “the only thing new is the history you don’t know”. – much appreciated:)

[BUDGIE]

I understood the reference to mean Queens Nautical Height. Thats what I was taught anyway!
Didn't the Brit's truly invent all things aviation and the Americans then 'develop' our ideas :p
I'm only jesting ;) but I do believe the 'Q' stands for Queen though.

Cheers
Budgie

[spekesoftly]

As in the old 'phonetic alphabet' perhaps? :-

QNH = Queen Nan How ;)


or even earlier :-

QNH = Queen Nuts Harry !

[QNH1013]

I feel so Flattered.

[Rote 8]

Although as far as I am aware QNH, QFE etc have no direct meaning QDR, QDM, QUJ and QTE do.

As has already been mentioned the Q is simply an indication that a morse code message is being passed (from the good old days)

DR = Direction Radial
DM = Direction Magnetic
TE = True Emnation
UJ = Union Jack

The last of these is a little obscure. Think Union Jack, think True To the flag (True to)

[criticalmass]

I always remember it as "Queer Notation of Height".

[Uplinker]

Surely, (don't call me Shirley), Q is for Question. In the days of morse code only, to keep a message short and simple, the letter Q meant question. As in; "--.- -. ...." = Question Nautical Height ? Reply comes back 1024 or whatever. (no I'm not going to attempt the number in morse code !)

[pilot-lite]

I was taught that QNH is

Query
Newlyn
Height

Newlyn being the place on the south coast of England where "Sea Level" is measured.

pilot-lite

['%MAC']

The posts have been very enlightening. These recondite concepts seem to hide in a malaise of phantasmagoria; it is hearting to know that there is a priesthood which maintains the knowledge (exempli gratia : those who have posted replies). Though the Wrights may have been the first in powered flight, it is obvious that aviation is a most international endeavour, with many contributions from various cultures.

[Don D Cake]

The Q does not stand for "question" or "query". To make the Q code a question you add a question mark after it. For instance QRA? is "what is the name of your vessel?"; QRA is "the name of my vessel is...."

[canucks2]

I believe QNH stood for 'Question Nil Height' as well. :confused:

[A Very Civil Pilot]

I thought that the Q-codes developed from radio, rather than aviation, basically as a shorthand to get the messade across. As in English, U always follows Q in a word, if you get a Q followed by something else, you'll know it's a Q code, and not a misread of the morse.

2 non aviation codes that I can remember are QRN - natural interference, QRM - man made interference (as in on the radio)

[Don D Cake]

You're not wrong. Anyone that can receive morse code at a reasonable speed automatically expects a Q code when the letter Q is sent. It really throws you when a Q code doesn't follow.

There are/were also Z codes and X codes too.

More q codes than you could ever possibly need....
List of Q codes (http://www.kloth.net/informations/qcodes.htm#qra)

And

List of Z codes (http://www.kloth.net/informations/zcodes.htm)

And while we're here, here's the evolution of SOS....

One of the first distress calls was CQD, coined by the Marconi Company about 1904 from the "general call" CQ and the letter D for "distress." The main problem with CQD was that it was supposed to be used only by ships which subscribed to the Marconi radio system and ships of one system were discouraged from communicating with ships or shore stations of other, competing, companies. The problem got so bad that it was taken up in the international radio conference in 1906 where a new universal distress call was proposed.

The American delegation suggested the letters NC which were already recognized in the International Signal Code for Visual Signalling. The German delegation proposed its own SOE which was already in use on German ships as a general inquiry signal similar to CQ (which was then used only by the Marconi system). The British delegation, of course, wanted to stick to the Marconi signal CQD.

The convention found SOE acceptable except that the final E could easily be lost in QRN so the letter S was substituted, making it SOS. The convention decided that SOS should be sent as a single code character with a sound unlike any other character, thus arresting the attention of anyone hearing it. So was officially adopted, but CQD remained in use for some years, particularly aboard British ships.

It wasn't until 1912, after the Titanic disaster, that SOS became universal and the use of CQD gradually disappeared. Titanic radio operator Jack Phillips sent both CQD and SOS to be sure that there couldn't possibly be any misunderstanding.

[Don D Cake]

Oh and another thing....

QNH was agreed at the Radio Telegraphy Convention in 1912, Newlyn was designated as the chart height datum in 1915 so I doubt the "NH" in "QNH" means "Newlyn height" or anything else for that matter.

[spekesoftly]

And another thing, QNH is used for 'Altitude', not height ! ;)

[Trislander]

Don D Cake-
Funny, I thought SOS stood for 'Save Our Souls'.

A question-
Are pilots allowed to use any Q codes these days, or is it now just limited to an official selection? i.e. Could I tell Exeter approach: G-CD, QSY Yeovil Radar 129.9...etc? ( I know that is not the corrcet freq. for Yeovil but just for the example!)???

Thanks
Tri

[DX Wombat]

..- .--. .-.. .. -. -.- . .-. .---- ----- ..--- ....- .. - .... .. -. -.- -.. -..- .-- :D :D :D

[HEATHROW DIRECTOR]

Trislander.. you could try but unless the controller is an oldie like me he probably wouldn't understandwhat you meant!

[P.Hendo]

I too was under the impression that the old "Q Code" system was derived as convention when Morse was the best / only form of communication. I was taught that the "Q" stood for "Query"? A "query" was sent and then answered......

Eg a pilot / navigator would send by Morse "QNH" and then receive the reply from the ground station "1013"

As the Q codes were so common the term has stuck, despite the terminology being outdated nowadays

ie: ....as mentioned before in other posts
QNH = query nil height
QFE = query field elevation
and so on

I'd like to know just how many theory provides actually do know the answer! (If in fact what I was taught is accurate!)