Fly heading 232 for 35, qfe 29.............

[Temphage]

I think the qfe figure, is the last two digits in the millibar pressure. (I.e. 13 in the standard 1013 alt setting (equals to 29.92 qnh).

 

Neg, taking off at... Tiblisi I think reports QFE 28, and the QFE is 'actually' something like 28.30.

[Focha]

In Europe, civilian operations, use QNH, if correct it will give you the field elevation and this is standard. But in some other cases, where is better to use other setting you use it, although not standard. For example, when flying helicopters in mountain (in VMC) we use QNE (standard, 1013 mb) as this will give us pressure altitude.

It's understandable that sometimes military aircraft use QFE (I think Russia use QFE in civil operations as standard which makes European pilots make some more math). Although they can also use QNH. You can always say a QFE based altitude with a QNH setting or vice-versa. You just add or subtract the field elevation to one of the settings.

So it's not a big deal if it's QNH or QFE. Although if you are in IMC, that is a different story, since charts have AMSL reference (and that was determined by MOC), so in this case you would use QNH.

 

Correct me if I am wrong here.

 

In the sim, they should say: "QFE 29.89". So my understanding is that it is incomplete. Simply saying "QFE 29" doesn't give you the accuracy you need.

 

Regards.

[636_Castle]

Seems like everyone is on the same page here then. Russian ATC normally gives pressure reports in QFE, all four numbers, millibars. It would only make sense that since the A-10's altimeter doesn't have a millibar window, the ATC is being kind enough to give us western USAF FOB pilots the QFE in inches, which you'd probably request IRL anyway. Now the question is, why isn't the report given in the standard ICAO format in DCS? I don't think anybody knows for sure.

 

EDIT: Dammit, Castle beat me to it.

:P:pilotfly:

Edited March 30, 2011 by 636_Castle

[Gunjam]

@ Rainmaker

 

If you set QNH on your altimeter it will read altitude above mean sea level.

If you set QFE on your altimeter it will read altitude above field elevation.

 

@ S77th-konkussion

 

Transition levels are different for each country and even regions, they are published in navigation supplements and/or even given in an aerodrome ATIS or by ATC.

 

Transition levels exist purely to separate traffic from each other by means of vertical distance. Above a certain altitude (transition level) everyone should put QNE (standard pressure) on their altimeter and report their altitude in 'Flight Levels' e.g FL090, below a certain Flight Level everyone should put the area/local QNH and report their altitude in thousand of feet eg. 9000 feet.

 

To put it (very) simple:

"Above the transition level you are mostly concerned about avoiding other traffic" i.e high altitude, en-route portions of the flight.

"Below the transition level you are concerned both with avoiding other traffic as well as terrain/obstacles and want to know your actual altitude above sea level" i.e approach and terminal area. (QFE also is sometimes used here instead of QNH, like in DCS A-10C)

 

This way makes it much easier to separate traffic when you for example have two 747's out in the middle of the Atlantic on opposite head-on tracks.

 

They have both set QNE (standard pressure 29.92) on their altimeters so if one is flying at say FL310 and the other at FL320 then they have an actual vertical separation of 1000'. What their actual altitude above sea level is, is not of much interest to them en-route.

 

Now let's say those two 747's were on QNH pressure with different settings. Say one had a regional QNH setting of 30.02 from New York, and the other 31.02 from London.

 

For ease of explanation, and to make the point clear, let's say that by chance the actual QNH of that part of the Atlantic happened to be the same as the New York regional QNH of 30.01. So the New York 747 "got it right" so to speak. This means his indicated altitude is correctly displaying actual altitude above mean sea level.

 

The New York 747 would still be flying at an indicated altitude of FL310, and the London 747 would still be flying at an indicated altitude of FL320, BUT they would both be flying at the same ACTUAL altitude.

 

Easy? :)

 

Gunjam

[636_Castle]

GGTharos replied to another thread earlier today and said it was a known bug. I hope it's fixed in the patch, it doesn't sound like a major thing to fix. I'm doubting it though, if people have been flying around with incorrect altimeter settings through beta 1, 2, 3, 4, release version, and .6 patch.

[nemises]

its definitely planned to be fixed, and I've seen the fix in action, but have no idea what patch it'll be introduced in....possibly 1108 ? (this is to increase the accuracy of qfe to2.2)

[Temphage]

GGTharos replied to another thread earlier today and said it was a known bug. I hope it's fixed in the patch, it doesn't sound like a major thing to fix. I'm doubting it though, if people have been flying around with incorrect altimeter settings through beta 1, 2, 3, 4, release version, and .6 patch.

 

Seeing as how QFE works fine in KA-50 I highly doubt it's a huge deal to fix.

 

 

On that note, ATC worked a lot better in KA-50. They respond to what you say immediately after you're done talking which makes it feel much more natural... instead of the awkward pauses you get now.

[effte]

<nitpick mode ON>

Transition ALTITUDES are published. When you climb through the TA you transition to QNE. The transition LEVEL is given by ATC and might vary depending on meteorological conditions, as it has to be high enough above the TA to ensure separation between traffic on QNE and QNH. As you descend through the TL you transition to QNH/QFE.

<nitpick mode OFF>

 

;)

 

QFE makes sense when you'll be taking off and landing at the same place, you'll be flying visually, you don't know the exact altitude of your take off location and there won't be ATC to give you altitude separation from other traffic.

 

Not visual? QNH is a better choice, as you'll be able to see your real altitude and compare it with obstacles in your map.

 

Going somewhere else? QNH is far better, as it varies only depending on met conditions, not due to field elevation.

 

You know your departure altitude? You'll be able to set QNH without getting it from ATC. See benefits above.

 

ATC altitude separation? QNH will enable separation between traffic in the area. QFE will cause a problem if the traffic originated from different airports.

 

 

In my neck of the woods, QFE has been the method of choice for military aviation due to the intended modus operandi. I've also spent most of my glider time on QFE, pretty much for the reasons outlined above, only switching to QNH when getting into controlled airspace.

 

 

QNH isn't sea level pressure. It is the pressure which gives you the MSL altitude at the threshold when at the threshold altitude. A subtle but important difference.

 

Cheers,

Fred

[airea]

Soi after all the debate of 6 pages, when the ATC says " QSE 29", how should we our altimeter? To 29something?

[BlackRazor]

If you watch the latest Wags' video (made with a pre-release version of patch 1.0.0.7) you'll notice that the altimeter setting is given with 4 digits.

[S77th-konkussion]

Soi after all the debate of 6 pages, when the ATC says " QSE 29", how should we our altimeter? To 29something?

 

I think that for right now- zero altimeter out for takeoff for landing at a different airport-- n/a-- not enough info provided to really mess with it.

 

after this patch- zero it out for takeoff. For landing you should be able to set the altimeter to the pressure given in the "inbound" callback..

 

If I'm not correct- please correct me in simple terms- applicable to DCS. While I do appreciate the RL technical info- giving out all that with no reference materials, and in the abscence of that detail in DCS ATC modeling-- honestly it's just confusing at this stage..

[BlueRidgeDx]

I see a lot of different ideas and assumptions in this thread. Here's a tad more info:

 

In the A-10, it's desired that you set the altimeter to whatever value is required so that the altimeter reads the known EOR elevation, or if not available, the Touchdown Zone Elevation (TDZE) of the departure runway; even if this value is different than the reported QNH or altimeter setting.

 

The reason is because the IFFCC will perform a Delta and Baro update of the system altitude at about 60 knots during the takeoff roll. This is to ensure the accuracy of the elevation data used by the IFFCC for ballistics computations during weapon delivery.

 

Once airborne however, it's essential to reset the altimeter to the reported QNH or altimeter setting to ensure that you're using the same pressure reference as all the other traffic in the local area.

 

Some countries and some militaries use QFE. The US in general, and the US military in particular, do not. There are a variety of reasons, but bringing them up is sure to invite an argument over which way is "better".

[S77th-konkussion]

Yes- but where is the reported QNH? I have only seen QFE reported.. that is unless I have gotten used to ignoring it due to the incomplete modeling..

 

Is this corrected here in this next edition?

Edited April 2, 2011 by S77th-konkussion

[Rainmaker]

Good news...

 

We now get our full 4 digit reporting...

 

Bad news...

 

Tower smokes crack. :megalol:

 

I got a QFE of 38.?? today when requesting takeoff from Kabuleti.

[miguelaco]

Same here :-(

[636_Castle]

I wonder if there's an LUA somewhere that'll allow us to fix it ourselves?

[S77th-konkussion]

Post -Patch .7 --

 

 

QFE 3980? :huh: I didn't bother to spin the altimeter dial a 1000 millibars, but that's several thousand feet higher than the 59 ASL indicated on the Kobuleti airport charts isn't it?

 

 

Edit-- I see I am fashionably late to this party..

Edited April 7, 2011 by S77th-konkussion

[Itkovian]

Hum, just where (and how) do you set the altimeter anyway?

 

I'm through the instruments section of the flight manual, and must have missed that part.

 

Thank you.

 

Itkovian

[GGTharos]

Obviously not. Still a bug to be fixed. Assume 29 not 39 ;)

 

QFE 3980? :huh:

[S77th-konkussion]

Yes- I did. Coincidentally, or not- when I dialed that # in- it happened to be -60 instead of +60.. Don't know if that matters or not..

[GGTharos]

You mean the displayed altitude was off by 120 feet?

[S77th-konkussion]

Yes- if I understand you. The "published" elevation was 59. That mB reading produced about a

-60 reading on the HUD, and of course- the altimeter itself.

 

 

Published-- shu's charts.

[GGTharos]

Alright, I'll have a closer look at this and report it as necessary - thanks!

[hog_driver111th]

Not to bring up that "which way is better" arguement... which I'm not, however, since the A-10C is a USAF jet, and the altimeter setting is in inches, shouldn't ATC call "Altimeter 29.92" like they would real world? Before anyone says it, I do understand that this is made for everyone... but since there isn't a millibars window, it should be announce in inches and not QFE or QNH... right?

[GGTharos]

I don't see him announcing anything in millibars ... maybe I'm wrong?