Compass headings?

[alb469]

Read an article about Alert, it mentioned that the runway headings are aligned to their true headings because it is above the magnetic pole. I have noticed when flying in the very far north that the rwys do not correspond to fs9 headings. Some headings are as much as 50 or 60 degs off. In the GPS as well. Is there a fix for this problem? Its a little upsetting when you think you are lined up on final and no runway in sight when you are 3 or 4 miles out or less!  :-/

[Calb]

How can you possibly even "think" you're lined up on final unless you have the runway in sight ?

Cal (CYXX)

[Woodlouse2002]

As the magnetic pole moves runways have to have their bearing in true otherwise it would never be correct.

Now imagine the magnetic pole is three degrees from true on the equator. The further north you go the greater the angle between true and magnetic will become which is why the difference between true and magnetic is so great the further north you go.

[alb469]

Yes woodlouse you are correct. I have been flying the DEW line in fs9 and for example one site where fs9 gave rwy headings of 20 and 200 deg.Going by the a/c compass and the gps Iwas lined up on 20 rwy when about a mile out you could see the gravel rwy almost directly across my path. The actual runway was at a guess 60 deg from 20 so we lined up by eye ball and landed. For an adventure in flying try the DEW line from Greenland to Alaska. My question is does fs9 have any way to compensate for this or does anyone have a formula to change magnetic to true depending on how far north you are.

[SilverFox441]

Magnetic deviation isn't just a factor of how far North you are...it's also how far East/West.

If you take a look at the image below it can be better understood:

You are looking at Earth from the top, the Black dot is the geographic North Pole, the Grey dot is the Magnetic North Pole.

An aircraft travelling along line "A" will see no deviation, it's aligned with both Poles...right up until it crosses over the Magnetic pole. It's heading will then flip over to South, even though it is travelling North still.

Line "B" is further West of line "A". An aircraft travelling along this line will see a small deviation at the equator that increases as it travells North. As it crosses the circle at "D" the deviation is almost 15

[Woodlouse2002]

I simplified my explaination somewhat, but now there should be no more queries.

[Calb]

The statement about the angle between true and Magnetic changing as you go north is oversimplified. If you follow a Meridian (go STRAIGHT north) it is so. However, you can go north and follow a line of constant variation. That line will take you to the Mag North Pole.

FS has always had a problem with it's presentation of the world in the far north. It's a built-in anomoly that results from flattening a sphere. There's no way around it. You either live with it or fly elsewhere.

I use FSNavigator for navigation and flight planning -- the only payware add-on (if ANY kind) I will ever buy. It allows me to see the runway in relation to my inbound track -- I am never surprised. I know well in advance how I need to plan my approach which is what any good pilot must do -- plan ahead.

Perhaps you already have these charts, I don't know, but if not, I suggest you go to http://bathursted.ccnb.nb.ca/vatcan/fir ... harts.html and download CAP1 (for runway layouts), Lo5, Lo9, Hi1 & Hi2. The Magnetic Variation is shown on them and the runway layouts in CAP1 should allow you plan ahead with GPS co-ordinates to get you lined up without reference to the compass.

And no, there's no formula or "fix" like you'd like. In this case you gotta compromise and innovate.

Cal (CYXX)

[alb469]

Thanks all for the help. I know from my own days in the airforce our navigators had trouble the further north we flew..I recall when in a search and rescue unit our albatross had a radar where the top of the screen could be set up for true north or magnetic north. It would be helpful if something like that was available in fs9. Or is that wishful thinking.

[Calb]

Did you ever have occasion to stop in at Winisk ?

Cal (CYXX)

[alb469]

Calb- Not that I can remember. The unit I was with  was based in CYTR. In my last 10 years it was with 437 squadron in the CC106 days.

[Calb]

1964-65.

In Sept 64 they sent us up an Albert (9304), piloted by F/L Christie to search for two Aboriginals feared drowned in Hudson's Bay. I went as a spotter for 3 hrs.

Another time, probably in early 1965, an Albert on its way down from Hall Beach put into Winisk to investigate a suspected electrical problem. They found the stbd generator lead came loose from the regulator box and was flailing around behind the engine. They were lucky.

I think they were from TR but I have no idea what Sqn.

Winisk was a Sector Station, part of the Mid-Canada Radar line (McGill Fence) put in place while they built the DEW line. It was located on the East side of the Winisk River where it empties into Hudson's Bay. You can still see the runway on Google Map.

Ah, the good ole days.

Cal (CYXX)

[Wingo]

I saw this for the first time today, landing at Perth Intl the runway was 30 but the heading was 16, not as drastic as other but still there

[Calb]

Ummmmm......  Perth?? As in YPPH ? As in Western Australia ?

YPPH doesn't have a Rwy 30

Cal (CYXX)

[beaky]

Ummmmm......  Perth?? As in YPPH ? As in Western Australia ?

YPPH doesn't have a Rwy 30

Cal (CYXX)

That might explain the heading of 160... LOL.

[beaky]

FS9's inaccuracy aside, the situation is even more complicated than just the magnetic and geographic poles being out of alignment...
This chart is from 1900, and doesn't show the far arctic/antarctic regions, but you get the idea... and as others have pointed out, the lines of isogonic force are drifting slowly but surely all the time.
  For those who don't know, that area where a bunch of lines converge at the top of N. america is the magnetic North Pole...
 The other trouble with mag. compasses near the poles is that the Earth's magnetic field dips lower closer to the poles(imagine the surface of an apple).
but things get pretty weird in other areas, too- check out the southern ocean regions!!