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QFE


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Hello

 

Sorry if this have already been answered in some of these posts, as far as i have seen the QFE on a target is vissible in the kneepages but only on the pre planned waypoints from the mission editor, not if you input your own waypoints like in a blue flag type of mission.

 

Is there some other way of knowing the QFE on the different places on the map or we will just have to live with being more unprecise in for instance blue flag?

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I guess you can guesstimate it by using F10 map, since it tells the cursor position's altitude above the sea level. Since the air pressure at sea level is 1013 millibars and the pressure decreases about 1 millibar per 10 meters, then you can calculate the appropriate altimeter setting from that.

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QFE

 

Good point. I need to figure out a good way to solve this, when I eventually (hopefully) have more time. The workaround for now is:

- When idling on the ramp/runway:

- Check the altitude on the location of your target point. Use F10-map and hover your mouse over the point and the altitude is then shown next to the latitude/longitude.

- Compare this with the altitude of the runway you are on.

- Subtract the runway altitude from the target altitude. If the target altitude is above the runway altitude, you should get a positive number, and vice versa.

- Set your altimeter so it displays the difference between the altitudes. For example if the runway is at 150m and the target is at 100m altitude then set you altimeter so it displays 50m. If the runway is at 40m and the target is at 80m set the altimeter so it is 40m below zero.

 

Hope that helps!

DCS AJS37 HACKERMAN

 

There will always be bugs. If everything is a priority nothing is.

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The Dream would ofc be if ED could add the QFE number to be displayable together with the altitude above ground on the F10 Map.

 

But the solution you guys made with the Waypoint / Kneeboard page is very nice and makes it a whole lot easier for us soon to be Viggen pilots =).

 

Though many of the players on the Blue flag servers are already into going a bit more hardcore on mission planning etc so im sure some of them might actually like the added complexity of having to calculate the target QFE setting using the technique Ragnar just mentioned ^^.


Edited by mattebubben
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I know this does not really relate to DCS, but how would the RL pilots figure that out? Specially if there is weather at the target area or vice versa, take off in weather while the target area is clear. QFE is affected by weather right? (atmospheric pressure)


Edited by mvsgas

To whom it may concern,

I am an idiot, unfortunately for the world, I have a internet connection and a fondness for beer....apologies for that.

Thank you for you patience.

 

 

Many people don't want the truth, they want constant reassurance that whatever misconception/fallacies they believe in are true..

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I know this does not really relate to DCS, but how would the RL pilots figure that out? Specially if there is weather at the target area or vice versa, take off in weather while the target area is clear. QFE is affected by weather right? (atmospheric pressure)

 

Well, most of the targets a Swedish Viggen pilot would encounter was always at the same altitude - sea level. So not something to worry about on a daily basis :thumbup:

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I know this does not really relate to DCS, but how would the RL pilots figure that out? Specially if there is weather at the target area or vice versa, take off in weather while the target area is clear. QFE is affected by weather right? (atmospheric pressure)

Yep, QFE depends on weather. Each air wing had its own meteorology section that did weather flights daily, usually more than once. Figuring out the target altitude was trickier. For preplanned missions (that is, the only kind of mission the AJ 37 flew for the majority of its career) you'd usually just look at a map (militaries love maps), so the kneeboard QFE data is a pretty good abstraction of this going on in the background. If you were doing something a bit more improvised you'd hopefully have a FAC or someone like that who could figure it out for you. If not, well, you'd have to either eyeball it or use the radar altimeter on a similarly elevated section of the terrain.

 

Artillery has the same problem of finding the target elevation, and the solution is the same - either you guess based on a map or you have your forward observer figure it out.

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Thanks

To whom it may concern,

I am an idiot, unfortunately for the world, I have a internet connection and a fondness for beer....apologies for that.

Thank you for you patience.

 

 

Many people don't want the truth, they want constant reassurance that whatever misconception/fallacies they believe in are true..

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U can calculate the QFE on any spot of the map as long as u know your current elevation and the target elevation, assuming that the pressure remains constant over the whole map.

 

 

Lets say your current elevation is 500 ft.

 

If u set the altimeter to zero, then you know your current QFE, lets say its 995 hpa.

 

Now lets say the target altitude is 2000 ft.

 

2000-500 = 1500, thats the difference in altitude between you and the target.

 

On a standard day 1 hpa = 27 ft, so 1500 / 27 = 55.5

 

Since pressure decreases with increasing altitude, you need to subtract 55.5 from 995 = 939.5

 

That is the target QFE.


Edited by addde
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There's a section in the SFI (flight manual for the real aircraft) that describes procedures for check flights - that is, test flying the aircraft after maintenance or some other event and putting it through its paces to ensure that all onboard systems are working as intended. When it gets to the part when you're checking the barometric altimeters, the procedure is as follows:

 

1. Level flight, 500 km/h IAS, 100m AGL, SPAK mode engaged, LD/RHM switch in RHM position (sets aircraft to use radar altimeter as altitude source)

2. Set the HUD reference altitude to 100 m as per the radar altimeter. Adjust barometric altimeter to read 100 meters and note down the pressure.

3. Accelerate slowly while keeping the 100m altitude, using the pole track on the HUD.

 

Note down by how much the barometric altimeter differs from the 100m reading at M 0.6, 0.8, 0.85, 0.9, 0.92 and 0.95. Ensure the differences are within permitted tolerances (haven't found where these are listed).

 

Note

This check shall be done over water, while flying parallel to the isobars and covering a distance over the ground shorter than 50 km.

By parallel to the isobars they mean ensuring that you're not flying towards or away from a low or high pressure center, so something like the blue line I've drawn here as an example:

 

YH2osyj.png

 

Does DCS model pressure centers at all? :V

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I've never figured dynamic weather out in DCS. I feel like I am missing out.

 

I have a deep strike mission I originally wrote for the Frogfoot which should adapt well to a Viggen, or possibly to a mix of aircraft with different opposition based on player choice, a la Asset Extraction. I have a lovely dynamic weather setup all ready for it.

 

It isn't all that hard, although bafflingly, there's no way to adjust it in the editor. You either have to fiddle with pressure centers until they're placed randomly more or less where you want, or edit the mission file to place them by hand. (You can adjust the pressures, though.)

Black Shark, Harrier, and Hornet pilot

Many Words - Serial Fiction | Ka-50 Employment Guide | Ka-50 Avionics Cheat Sheet | Multiplayer Shooting Range Mission

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I've never figured dynamic weather out in DCS. I feel like I am missing out.

 

I never master it either and I really do not understand much of it, but I tend to create missions with 6 systems ( with various pressures) and through trail and error have manage to takeoff with little wind and few clouds and the target area might have rain and strong winds, so it will be interesting to try bombing like that.

To whom it may concern,

I am an idiot, unfortunately for the world, I have a internet connection and a fondness for beer....apologies for that.

Thank you for you patience.

 

 

Many people don't want the truth, they want constant reassurance that whatever misconception/fallacies they believe in are true..

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