How to Deal with Magnetic Variation?

[exhausted]

What's the correct way to do this, by the book? 

What do pilots irl actually do?

What do pilots in game actually do?

[Sarowa]

 

[VZ_342]

Subtract an east mag var, add a west mag var.

Example: Mag var is 12⁰ East, your desired heading on a map is 120⁰ = fly 108⁰ to get where you want.

[Lace]

48 minutes ago, exhausted said:

What's the correct way to do this, by the book? 

What do pilots irl actually do?

What do pilots in game actually do?

The magnetic north pole is not in the same place as the geographic north pole.  To complicate this further, it moves, and to complicate it even further still, the magnetic field is not constant across the globe.

Each place will have a variation value which is valid for that chart issue date.  The chart should also show the rate of change. 

IRL, when flight planning you draw a line on a chart and read off a true bearing.  You will then convert this to a magnetic bearing using the variation value, and you will then convert it again to a compass value using the compass deviation value as placarded in the aircraft.  Note the values could be positive or negative.

C = D+M = V+T

Compass = Deviation + Magnetic = Variation + True

Cadbury's Dairy Milk Very Tasty.

It also works backwards, which is more useful when going from a chart to the aircraft

T+V = M+D = C

True Virgins Make Dull Company

Depending on where you are, and therefore how big the variation is, will depend on what you do with it.  a 1 degree error on a 60nm leg will result in a 1nm error.  If the deviation is small, and your typical leg distance is small, then you may well disregard it (most pilots can't hold a heading accurate to 1 degree anyway, 5 is more realistic for most VFR fliers, even in good weather).

I can honestly say that I've never used it in DCS.

There is a good app you can download called Aerovariation, which will give you current and historic values for anywhere on earth.

AeroVariation on the App Store (apple.com)

 

[exhausted]

Hey yall, I get the concept and the math is for those want to deal with the theory and the numbers.

@VZ_342 this is the solution I have been using, but I would like to know if the F-5's gauges can be adjusted for magnetic variation at the start of a mission, so you don't have to keep doing mental math on the fly.

[Lace]

Mental math is a big part of flying.

[razo+r]

11 minutes ago, exhausted said:

Hey yall, I get the concept and the math is for those want to deal with the theory and the numbers.

@VZ_342 this is the solution I have been using, but I would like to know if the F-5's gauges can be adjusted for magnetic variation at the start of a mission, so you don't have to keep doing mental math on the fly.

In a "recent" update the ruler now shows both Magnetic and True heading, so you just have to pick the correct one.

But besides that, the HSI should show magnetic. If it doesnt try pressing the FAST ERECT button.

[some1]

12 minutes ago, exhausted said:

I would like to know if the F-5's gauges can be adjusted for magnetic variation at the start of a mission, so you don't have to keep doing mental math on the fly.

They can't because real western pilots rarely have to deal with true bearings. Their charts use magnetic north, runways are referenced by magnetic north, VOR and TACAN use magnetic north etc. At least most of the time.

DCS map is skewed by its Russian origins, where use of true north in aviation is more frequent. Same with using QFE instead of QNH by ATC. 

 

 

[=475FG= Dawger]

Ignore it.

If you are VFR, look out the window and navigate via pilotage.

If you are not VFR, you are flying radio nav, in which case just follow the needle.

It only really matters when IFR trying to do precise dead reckoning and the maps are so small in DCS that it doesn't really matter.

[RustBelt]

On 9/22/2023 at 3:24 PM, some1 said:

They can't because real western pilots rarely have to deal with true bearings. Their charts use magnetic north, runways are referenced by magnetic north, VOR and TACAN use magnetic north etc. At least most of the time.

DCS map is skewed by its Russian origins, where use of true north in aviation is more frequent. Same with using QFE instead of QNH by ATC. 

 

 

Don’t forget the backwards wind directions. Who cares where the wind is going. Pilots need to know where the wind is coming FROM.