Does FS9 Have A Gauge for True North?

[codetrucker]

Hello,

 

I have been trying to perfect my Celestial Navigation (CelNav) as opposed to just following a magenta line on the GPS. I attempted a flight from Whitehorse (CYXY) to Stevens Anchorage (PANC) which was a distance of 457nm. I embarked attempting to use the brilliant "Bubble Sextant." Long story short, I ended up near Eielson AFB, some 200-ish nm north of my intended destination. "What happened?" I thought when I took a glimpse at my GPS. Well, the problem was my not taking Magnetic Declination" into account or adjustment. Armed with new knowledge I tried the same flight. Only 20nm north of PANC this time. A 90% improvement, but not good enough in anything other than clear skies and hight clouds.

 

Like the subject says, I am looking for a gauge(?) which will allow me to check the difference in my magnetic compass heading against the True North standard. I attempted to search for over six hours (no joke), so I am here to seek assistance from those far wiser than myself. Does anyone else miss Opa? :)

 

Thanks for reading.

 

Calvin

[tiger1962]

You might find something you need here: http://www.kronzky.info/fs/

If not, the Driftmeter by Dave Bitzer might help: http://www.dc3airways.com/useful/downloads/gauges.htm

[jgf]

I've often thought these navigation anomalies were due to FS9 being a product of the Flat Earth Society. The FS9 world is mapped onto a flat plane, not a sphere, so coordinates are not linear and get worse the farther from the equator you go. Perhaps this is why you cannot fly over the poles in FS9, the coordinates become so off kilter either the game cannot process them or you couldn't navigate by them.

[Roger Wensley]

FS9 cannot deal with any scenery objects above 75 degrees north, that's for sure. I have tried with Grise Fiord CYGZ at 76 North! But ignorance of true north in a plane at the northern end of Baffin Island and searching for Pond Inlet just sounds like real life to me, even though runway headings in the "Northern Domestic Airspace" are given in degrees true and not degrees magnetic. Given that in the north a compass cannot be relied upon to tell you where magnetic north is, I would be surprised if any instrument on a plane would be able to tell you what the declination is between the magnetic that it cannot reliably measure and the true north. There is a free magnetic declination calculator at Natural Rescouces Canada that enables you to find out what the declination is at any point in Canada, but this is based upon what has been measured this year, not what it actually is at 3pm this afternoon. However, if you can feed in a series of declinations to your system you may be able to improve things. Or maybe feed in the whole range from NRC, if that is possible?

[tgibson_new]

Actually, to get within 20 NM on a 500 NM flight is within the limits of the sextant, so I don't think you could improve on that (or should you). In their manual, they state you should assume a 1 in 10 error, so for a 500 NM flight you should assume a possible 50 NM error. In anything but vintage days, once you are within around 50 NM of PANC you would pick up some kind of homing beacon (NDB or VOR, depending on the era), and that would guide you right to the airport. That's how the real ones did it. If there is no radio aid, then follow their instructions to offset your course north to allow for the area of uncertainty.

 

Now the manual doesn't describe flying in the far north, and that's where your problem comes in. Flying using magnetic headings is just about impossible in some areas. In the later years of the propliner era, they used a Polar Path Compass, which was an early form of INS (i.e. gyroscopes) used in the later early jet era. Before that, they used navigators and a Grid chart. This chart had a grid laid over the north pole, and the navigator could plot their position via the sextant, and estimate course *corrections* that should be made (not an actual magnetic course).

 

And that's what you could do as well. Create a chart with the great circle route you want to use. Fly out using a navaid using a known heading to your destination airport. Once you lose the navaid, fly a straight course (ignoring the magnetic compass) until your first sextant shot. When you have your position, plot it and estimate how far off the great circle route you are. Have the pilot turn towards the correct route, and wait. Then take another shot and repeat. This way you do not need true or magnetic courses - it's all based on positions and corrections.

 

If you don't want to go to the trouble to create a paper chart, this can be simulated by creating a great circle route to your destination in the GPS (Direct to Waypoint is fine if you don't want a flight plan). On your flight keep the GPS hidden. Every 20 minutes or so, take a shot and get your plane's position. Then pop up the GPS (simulating the navigator's chart) and check your position vs the great circle route. Then adjust your course to get back to that route. Again, ignore magnetic headings, just "turn 10 degrees left". Then hide the GPS and fly a straight course for another 20 minutes. Repeat as needed.

 

Hope this helps,

[Roger Wensley]

I am reminded of another technique by Tom's "offset to the north" so that when you should have the destination in sight you turn south to look for it.

This other technique works in featureless flat terrain and you fly a course that should get you to the destination if there is no wind. When you have flown the distance to the destination you turn and fly upwind. Good for finding a vehicle in the desert.

[davidjones]

Shift + Z will give you your game latitude and longitude on demand...

 

DJ

[Roger Wensley]

Shift + Z also does not exist in a real plane.

[louross]

If I understand correctly, fs is "built" on a cylinder, not a round world. Therefore, you can only go so far north, and there is no more. Read that once in a forum, but that was many moons ago.

lr.

[tgibson_new]

Neither does a GPS in this era, but sometimes we have to remember that this is a simulation. :)

 

That said, there is nothing keeping a pilot from also being the navigator, doing it all using a sextant and a paper chart. But you are going to be very busy.

[davidjones]

Shift + Z also does not exist in a real plane.

 

Nor does a local magnetic deviation gauge. What's your point?

 

DJ

[Roger Wensley]

Nor does a local magnetic deviation gauge. What's your point?

 

DJ

 

Reality

[il88pp]

codetrucker,

The link by tiger1965 looks promising.

I didn't try any of it out. Did the tools in that solve your challange already?

 

If not,

I think a gauge like this is an interesting idea.

It takes your position on earth and your magnetic heading,

It uses "magnetic north" and "the position of the magnetic pole" vs "the position of "true north pole",

And then uses that to calculate the difference in angle.

 

Much easier would be to make the gauge like this:

Assuming a primitive plane. (Magn Compass, and Sextant, only. No INS/MFD.)

Take your 'heading magnetic'. (you see that on your compass in the VC as well.),

Takes your 'heading True'. (You don't see that in your primive plane)

(Both those variables are extracted from FS2004 by the gauge, no manual input needed.)

-->>Then let it calculalate the difference between heading Magnetic and heading True. (Simple substraction.)

 

..-->>..---->>Example:

Magnetic is 285 degrees.

True is 192 degrees.

gauge spits out "Magnetic variation is:" "+007"

(no input of coordinates of any kind needed when doing it this way.:D)

----------------------

Would that suit your purposes?

Suits you sir, suits you.... (Monty Python -like series, can't remember name, but great sketch. Guy buying suit.)

(Ah, found it, it's from "THe fast show" (BBC))

 

Anyway, would that do?

 

I can fully understand you want to make it difficult for yourself (no MFD), but not make it impossible,

and give yourself an option to cross-check. Sound approach to have a fallback system.:)

 

 

-----------

I think the idea of using your position on earth is tantilising.

But I see problems along that path.

-I never made a gauge using coordinates.

-One of the required inputs would be the positions of True north pole, and magnetic north pole.

(with the difficult addition that the position of the Magnetic pole moves a bit each year.)

-Then, for what year to make the gauge, because:

-what year 1: It needs to work if you choose to fly with date set to today, but also when you prentend to be a 1944 Ace.

-what year2: To what year does the fsx star-sky apply.

As far as I know positions of stars change from year to year. (very slightly). A star that rose in the East on Sept-1 1817, 100 years ago, may not rise there today.

 

But, as some of you can probably see from the above, I aint the 'astrologist' I used to be!!!:):D lol.;)

 

 

------------

Let me know if that was sort of what you were thinking. (True - Magn --> Variation (-/+) )

 

il.

 

PS: I'm not one to use the Sextant for navigation.

If I do create a gauge, I would test basic functionality. (Let it calculate Variation in various locations).

I would not do a flight using the sectant and my gauge together. I would leave that kind of testing to you.

 

PPS: I can't give any promises on time frame. Making a gauge is best done in one go. Not in short spaced bursts. So I need a couple of quiet days to do it in. Quiet das gouped together are a rarity these days.:);)

 

The sooner you get back to me with an answer, and some feedback on my thoughts, the sooner I'll can your gauge on the calander.:D

il

[il88pp]

Maybe i need to rethink this. I looked up 'declination'.

Found an article on celestial declination. It looks like it's a lot more complicated then I first thought!:)

[tgibson_new]

Your looking for magnetic variation, not magnetic declination.

 

A gauge would be simple - just display the output of (A:GPS MAGVAR, degrees).

[il88pp]

Thank you HEAPS Tom!! :D

il.:cool: