AJS37 Viggen: Calculating QFE Tutorial | DCS WORLD

[@glennharrall8655]

QNH is sea-level pressure. It’s used to cause the altimeter to register height above sea level. When sitting on the ground at an airport, dialing QNH into the altimeter will cause it to display the airport’s altitude above sea level. QFE is air pressure at the current ground level. It’s used to cause the altimeter to register height above the ground (for a certain area). When sitting on the ground at an airport, dialing QFE into the altimeter will cause it to display zero feet. Western countries largely standard on using QNH during takeoff and landing. It allows you to accurately know your height above sea level, but you must know the height of the local terrain to know if you are at risk of impacting terrain. Eastern countries have sometimes standardized on using QFE, which allows you to know your height above the airport by just reading the altimeter.

[@grimreapers]

thx

[@AdurianJ]

or you can just take advantage of your altitude meter that measures in meters and take the height of your starting airfield settings minus your target height and voila you bypass knowing the QFE

[@grimreapers]

Interesting. Man this plane is complex. It makes my brain mushy.

[@W4lkerWings]

But If you have 'fog of war' enabled on your F10 map you'll need to use the 'on the fly' method.

[@davinci69]

You can also get the QFE for any waypoints from the kneeboard

[@wrmusic8736]

Converting feet to meters is an unnecessary step. You can just do QFE = QNH - alt / 30.5 for feet.

[@LazyBoot]

I think if you disable the "slav si" (set to F) switch it'll stop the symbology going away. Also, it's easier to get fine readouts if you press the reference button to set desired altitude.

[@voradfils]

I can recommend speedcrunch for doing calculations on the fly. Setting up custom functions is pretty straightfoward and it'll remember them over sessions. Autocomplete makes it very fast to use, too.

[@grimreapers]

thx

[@PaletoB]

Yeas, I needed this

[@PaletoB]

Oo right, happy Christmas and all that

[@smashy152]

python code for a viggen qfe calc while True : altfeet = input("Target Altitude ") qnh = input("Current QNH ") altmeters = (altfeet*0.3048) qfe = qnh - (altmeters / 9.3) print(qfe)

[@diacoal2433]

You need to put your altfeet and qnh inputs inside an int() or float() function, but otherwise nice code! Here is my slightly modified version, that makes you input the QNH once and then returns the QFE at any altitude in feet that you input.

[@fatalwarium]

@@diacoal2433 you forgot to put it here it is while True: altfeet = int(input("Target Altitude ")) qnh = int(input("Current QNH ")) altmeters = (altfeet*0.3048) qfe = qnh - (altmeters / 9.3) print(qfe)

[@wrmusic8736]

@@fatalwarium why do we even need conversion to meters though? You can just divide feet by 30.5 and then subtract the result from QNH.

[@brucewelsh1969]

Merry Xmas Cap.

[@grimreapers]

Merry Xmas

[@Scott.Farkus]

I'm trying to figure out what Lochini ATC means when they say QFE 873.29 when they give me take off clearance in DCS Huey.

[@bobburger137]

Happy Christmas all from the 🇬🇧

Rocket attacks and dive bombing is normaly done with the radar altimeter.

[@The_RussianBias]

the viggen cant use it for ground attacks

[@paulf1389]

Reapers recording on Christmas Day?????? Merry Christmas Cap.

[@grimreapers]

Merry Xmas

[@terryboyer1342]

we're gonna go after this hostile here. it's actually a friendly but we'll bomb it anyway. Well Merry Christmas!

[@S.ASmith]

Practicing for the USAF.

[@Paveway-chan]

Merry capmas!

[@grimreapers]

Merry Xmas

[@blasiushun]

QFE: Question is Field Elevation, aka russian used method QNH: Question is No Height, aka the 29.92 used in civil aviation everywhere else

[@mariushusejacobsen3221]

2992 is used over a specific altitude range to keep from having to readjust the altimeter setting every leg of a long flight. It's important everyone has separate altitudes, so the setting has to be synchronized, and rather than force pilots to update it every 15 minutes, they simply set that standard value. QNH is the airpressure at sea level for the location you're at. Meaning if the ground fell away, like it happens visually in dcs after having looked at something the other side of the map, that water height below you is where an altimeter set to QNH will show 0. In static weather, that's sea level anywhere. In dynamic weather, it'll vary with location, in particular distance from the various pressure system centers. QFE is the air pressure at ground level at a specific location. Field Elevation because that's what it was, and is, typically used for - the pilot needs to know the 0 elevation setting for the airfield he's approaching. The viggen uses that same method to find the altitude part of its ballistic calculations.

[@grimreapers]

thx

[@monkey.360]

I've just got his module, please tell me that there is a simpler way now as this is 2 years old....

[@grimreapers]

yes! It will be written in your kneeboard under the waypoint.

[@monkey.360]

@@grimreapers great, thanks for makes it easier Thanks for these vids they really do help novices like me.

[@jubuttib]

@@grimreapers You called this "cheating" in the video, Viggen flyers prefer the term "planning". =)

[@aliebalieb6731]

Just easy explained: All Q-Codes came from naval-morse-code. QNH = Altimeter shows Altitude above mean sea level. QFE = Altimeter shows Altitude above ground...that means when you sit on the runway altimeter shows Zero. So if you get QNH from the tower and want to know QFE, simply turn the Altimeter knob until the needle shows ZERO...then you can read the QFE from the altimeter-pressure number

[@grimreapers]

Thx. Cringey old vid :(

[@ilhankesmez183]

@@grimreapers as barometric pressure varies with weaher and altitude there is two reference points that you can use for altitude, eighter the sea level is assumed 0 then you have qnh as barometric pressure for 0. or the field you are taking of (or landin) is assumed 0 then you have qfe as barometric pressure for 0

[@olroxmo4050]

Thx Cap.

[@cmibm6022]

I would not recommend the 2nd method for a shooting target ;-)

[@jubuttib]

Wouldn't recommend using the bombs or rockets of the Viggen for those either. Better off with e.g. Rb-75s, at which point you don't need the QFE. =)