What does the Q stand for in QDM, QNH, QFE ?

[PompeyPaul]

I've often wondered what it stood for, as I understand it

QFE = Field Elevation
QNH = National Height ?
QDM = Direction Magnetic ?
QDR = Direction Reciprical ?

So in all of these, what does the Q stand for ?

[homeguard]

the 'Q' simply stands for 'quick code', initially morse of course

[Foxy Loxy]

See here for more info:
http://www.kloth.net/radio/qcodes.php

Foxy

[Whopity]

The Q code is a "Question" and Answer code designed for telegraphy use, first wired then wireless.

The Question is followed by a morse ? mark(..--..). The reply does not have the Question mark thus identifying it as the reply.

QFE? = What is the QFE?

QFE 1013 = The QFE is 1013

So Q stands for QUESTION

CAP1 AP1529 dated Nov 1945 shows that QNH did not exist at that time; QFF was used to measure barometric pressure reduced to sea level at an aerodrome.

[effortless]

homeguard has it in my book, Q= quick not question since responses often begin with q

[Keef]

When I learned it all for my RAE in 1960, it was just that the letter Q in morse wasn't allocated to anything else. There are (or were then) no country codes beginning Q, so you knew if you heard a Q that an abbreviation was coming.

Lots of people, later, tried to come up with clever rationales for the Q.

The codes began with QAB and ended with QZY. For some reason, QAA and QZZ were not assigned.

There is also a (far more obscure) Z-code, used only by military radio ops and teleprinter types. They are mostly ruder (like ZAA = You are not observing proper circuit discipline - I reckon we could use that in aviation ;) ).

One could bore for England on this...

[Whopity]

But QAA is assigned. At what time do you expect to arrive at .....? CAP1

Q Codes predate the allocation of Country Code Callsigns and the very reason there are no Qs used is because they were allready used as an established code.

[DFC]

It stands for "Wake up and pay attention to the next two letters"

It does not stand for question because the code can be both a question and an answer;

QNH - What is the sea level presure

QNH - The sea level pressure is (......)

or QTH - What is your position

QTH - My position is (........)

The whole idea is to prevent repetitive strain injury for the sparkey down the back and to ensure that he is awoken from his slumber by God Save the Queen every time.

Regards,

DFC

[sternone]

I've often wondered what it stood for, as I understand it


I find that a very very very good question!!! i wondered that for ages!!

[J.A.F.O.]

It's definitely not "Question", if it is indeed anything at all. As to ask a question one prefixes the Q code with interogative, in morse that's INT barred.

.._._

I've never been able to forget QRM - I am being interfered with - though I never got to use it as much as I would have liked.

[Whopity]

The Q code was a development of the old Post Master Generals telegraphic information code based upon 2 letters RA to RZ and SA to SF. The Letter Q was added in July 1912 as the first letter of the new code code (QRA-QRZ and QSA-QSF) that was then adopted Internationallly in July 1913.
QNH - What is the sea level presure Wrong DFC!
The Q code must be followed by the Interogative to make it a question. Anyone hearing QNH on its own will listen for the numeric group to signify the pressure because without the interogative it is part of an Answer or Statement!
QNH? = What is the sea level pressure

The primary purpose of the code was to determine information which starts by asking a question. There were so many other codes used in telegraphy because to send "quickly" you have to use abbreviations. (Note how all the old telegraphic codes are reappearing in SMS) This was one of the first attempts at International standardisation.

[smith]

You learn something new every day, an instructor told me the Q was for Queen's code and the Q codes were set up during the war to confuse the Germans (they confuse me enough so don't know how the Krauts would have got on with them).

Doesn't make sense now really as it was a King that was on the throne during the war.

[DFC]

Whopity,

If you are on the ground, receiving QNH from an aircraft is a question because you are the one that gives out that info.

If you are on the ground and receive QDM, you know it is a question because you are the one wo can provide that info.

If you are in the air and you hear QDM you know it is not a question because the person on the ground is the one with that info.

You have to forget all the R/T you have used / learned when dealing with old W/T.

QTH 10 South QFE QFU

QFE 1010 QFU 270 QAF 5 South

Which of the above do you think is the air and which is the ground?

Regards,

DFC

[Ringway Flyer]

Fyi - QNH = Question - Newlyn Harbour. (the mean sea level reference point) for your height above sea level....

[Ringway Flyer]

Look at THIS:- http://www.kloth.net/radio/qcodes.php

:ok:

[DickyPearse]

My vote is for "question" too.

ie. Question - nil height. It was all about removing excess words in the early days

[BEagle]

I'd believe Whopity, chaps.

After all, he did start flying just after people stopped waving flags, flashing mirrors and sending smoke signals.......;)

Actually, I've seen the original Q-code book at a squadron history display and it is exactly as Whopity (a long time radio amateur) decribes.

Mind you, QRB confused many people during my BFTS course.

[HappyTrails]

I understand it as QUERY.
as in Query Nautical Height, Query Field Elevation, Query Direction Magnetic.
Then again I have'nt completed my PPL yet so stand to be corrected.

[smith]

A bit of thread creep but always remembered QUJ as TRUE TO the flag (station) (UJ being Union Jack)

[DFC]

Wopity,

Sorry, you are right if by "the Interogative" you mean a note of interrogation signal (IMI). .. -- ..

Here is the details;

ICAO PANS Doc8400 :
The ICAO Q Code
1. The meanings of the Aeronautical Code signals were assigned by ICAO.
Since, in general, only stations of the Aeronautical Service will have available copies of the Aeronautical Code it should not be used in communications with stations of other services unless it is known that the station concerned is familiar with the code.

2. Q signals may be amplified or completed by the addition of appropriate location indicators, approved abbreviations, signals, call signs, figures or numbers.
2.1. The information necessary to complete a signification, as indicated by a blank space, shall be given except when:
(a) The blank spaces are enclosed within parentheses to indicate that their completion is optional.
(b) an alternative meaning shown in parentheses is selected and the blank space in this alternative meaning is completed.
2.2. The information used to complete the blank spaces shall be sent immediately after the Q signal in the sequence shown in the signification.
2.3. Expressions or words in parentheses which do not include blank spaces have the following significance:
(a) when following a blank space, the explanation of the information to be used in filling in the preceding blank.
(b) when following a word or expression, an alternative to the word or expression.
2.4. Q signals shall be read as a question when followed by a note of interrogation signal (IMI). When a signal is used as a question and is followed by additional or complementary information, the note of interrogation signal shall follow this information.
2.5. Q signals that are capable of being given an affirmative or negative sense shall be read in the appropriate sense when immediately followed by the signal YES in the case of the affirmative or the signal NO in the case of the negative.
2.6. Q signals used in the aeronautical service that are capable of being given the sense of an order shall be read in this sense when immediately followed by the signal ORD.
2.7. Q signals with numberes alternative significations shall be followed by the appropriate figure to indicate the exact meaning intended. This figure shall be sent immediately following the Q signal.
2.8. All times shall be given in Greenwich Mean Time (GMT) unless otherwise indicated in the question or reply.

Regards,

DFC

[Whopity]

Thankyou.

The Interogative is indeed a morse question mark ..--..

If "Q" was for "Quick", by adding Q to a 2 letter code it would have made it slower than the original code possibly even qualifying as an "S" code!

--.- .- --.- ..--..