Tower Q's?
-
ive been trying to figure out what to QNE, QFE, QHE stand for in the tower menu and when to use them… i know they are for the altimeter but not the specifics…until recently i was using QNE to try to zero out my altimeter but always had 500 ft. until randomly during ramp start requested QFE and got it zeroed and was hoping to find out what they actually mean and how they are used…this is my first time trying to post a thread or anything like this so i hope this this is the right way of going about getting this info. any help would be great and thanx ahead of time. i love this sim and have learned a lot from this site! every time i learn something new about this sim something inside me wants more!
-
They don’t stand for anything.
QFE altimeter reads 0 at runway surface
QNH altimeter reads field elevation at runway surface
QNE altimeter reads pressure altitude (29.92)They are Q-codes from back when morse code meant something.
-
This post is deleted! -
scenario’s for use other than QFE that ones pretty obvious… is field meaning grassy area or…? and when would i need and what is “pressure alt”? sorry if these are basic questions but i am really interested in this stuff and would like to know incase i am ever asked.
-
QNE is used above a certain altitude in all countries (and it’s different in every country/region) so that everyone is operating on the same altimeter setting. In Korea that altitude is 14,000 feet.
Field generally refers to anything that aircraft operate out of.
-
Sorry for the slang. Field is short for airfield also known as airport, aerodrome, airbase, etc. Back in WWI and even WWII days airports were just grassy fields.
You’d set QNE when you wanted to stop talking about “altitude” and start talking about “flight levels.” In commercial and other high-altitude long-distance operations most times all airplanes switch to a single altimeter setting above a certain altitude. This means that at a reading of 22,000’ on the altimeter will probably not be at that altitude. But this is OK because all other planes are using the same setting too and all airplanes will be wrong the same amount so spacing is preserved. You can fly the entire route on this setting and only have to change when descending to land because only then does true altitude become important again.
But AI in BMS do not fly pressure altitude “flight levels.” They flight true altitude so it is a good idea that you do so too. Because of combat considerations (bomb dropping calculations) and AI you will probably never use QNE setting.
You probably won’t use QFE either since that isn’t something USAF does very often. It’ll be QNH 99.99% of the time, once before take off and again when landing to make sure it didn’t change since takeoff.
-
thanks for clearing that up for me… so i want the"Q" that brings my altimeter to 0 ft when parked doing ramp start then right?
-
QNH (field elevation) is most often used when parked at ramp start.
-
QFE is the “poor man’s radar altimeter” showing 0 at the airfield surface but you really want to use QNH.
http://en.wikipedia.org/wiki/Q_code#Aviation -
QNH (field elevation) is most often used when parked at ramp start.
Depends on nation and/or SOP regulations, I suppose. There are some countries that still use QFE by default.
-
They don’t stand for anything
Incorrect. The Q stands for ‘question’ and so the whole abreviation is a request. Indeed in morse followed by a question mark it means a request for whatever follows. Without, it will be follow by the value.
QFE = Field Elevation
QNH = Nautical Height
QNE = Nautical ElevationSince the radios its hard to hear the difference wether someone is asking so you add ‘request’ before the abbreviation.
Thus where ‘QNH?’ Woul be in morse we say ‘request QNH’. The reply would be the same as in morse. ‘QNH 1030’ for example and so we also reply by radio. -
Incorrect only the Q stands for nothing.
QFE = Field Elevation
QNH = Nautical Height
QNE = Nautical ElevationThat’s also how I remembered what each Q meant, even though it’s technically wrong. QNH is used to know your ALTITUDE above sea level, whereas QNE and QFE are used to know your HEIGHT above sea/ground level. Might be a bit confusing to have the only Q using height in its “name” not refer to height at all.
-
I think you missed part of my message eagle. I was editing it that will explain the Q.
What you say about the abreviations is incorrect aswell. They infact ARE correct. They just dont refer to the aircraft’s vertical position (as most people mistakenly assume) but referes to the vertical position of the pressure level you are referencing with your altimeter.
With QFE you dail in the pressure which is dominating at the local ground level. Thus the pressure level you reference is the one of the field ELEVATION. Hence the name…
You now read the ‘height’ of the aircraft.
Not used in practice in aviation. Although I assume this is the setting of choice for a carrier landing.With QNH you dail your altimeter to the height of the mean sealevel. Which could be a certain value above or below the standard. You now read the ‘altitude’ of the aircraft.
The QNE is pure pressure LEVEL referencing. Standard atmosphere barometric pressure is 1013 hpa. So you tune in that. Now…when you fly at sealevel you know the EVEVATION of the sea compared to standard atmopheric conditions Again its pure pressure LEVEL referencing so we now see ‘flight level’ on our altimeter.
-
Not official, but from word of mouth / tradition I was told the “Q” is some maybe greek “word” for pressure.
In the 737, theres an artificial feel unit that provides feel to the elevator controls based on pitot pressure, the unit which senses this pressure is know as the “q-pot”.
-
Negative. Read my 2nd post above….
-
so if i wanted to do a fully heads down instrumental landing qfe would be most effetive so i dont hit the runway before expected by the altimeter, and i should also request this again upon approach or during arc because this may change from take off to landing time? thanks for all the great info.
-
Charts usually have both altitude (QNH) and height AGL (QFE) on them, so you could use both. Only thing you can’t use is QNE.
-
so if i wanted to do a fully heads down instrumental landing qfe would be most effetive so i dont hit the runway before expected by the altimeter, and i should also request this again upon approach or during arc because this may change from take off to landing time? thanks for all the great info.
Theoretically…yes. and what eagle eye says is true aswell.
However IRL QNH is used at all times, taking the field elevation into account. -
thanks guy i think i got it now … i actually jus started another thread…probably see you guys there too… thanks again everyone!!!
-
I believe Q stands for question or more likely query but I believe the meaning of the following two letters has been retroactively assigned to aid memory. If you look at the other Q codes the suffix isn’t tied to the meaning of the content. People assign memory aids to the suffix and until I see the 1929 telegraph handbook explaining the suffix letters that’s what I’m going to believe.