Flying a polar route in FS

[mkonareff]

Hi all,

I know that polar route has been explained in several topics here, but I am still not sure about how to perform a polar flight.

In fact, The B377 seems to not be equipped with a Polar path compass like the DC7 or the Starliner and I do not really know how to follow true headings on a polar flight with the B377.
After reading again the propliners tutorials I know how to simulate the navigation with celestial navigation and the use of the FS9 GPS time to time to simulate the navigator reports but how to apply these advice where the magnetic headings are not reliable anymore?
The B377 is equipped with a slaved gyro with a flux gate which corrects the gyro drift and the only way to fly with this gyro is to fly magnetic headings...

So, how to fly correctly a polar route with the stratocruiser or any other aircraft without polar path compass?

Many thanks by advance.

Cheers,
Maxime.

[Tom/CalClassic]

It's not equipped with the polar path compass since it was not flying polar routes when the compass was developed in the late 1950's. In fact, I don't know of any polar routes that it ever flew. It was typically a transatlantic and transpacific aircraft. It really didn't have the range for true transpolar flights.

For polar flights they used special grid charts with lat and long values for positions (as I remember?). Before the polar path compass, they used celestial navigation to locate their position, and still used it after that to confirm/refine the PP compass results.

Do a web search for:

polar grid navigation

and you should get plenty of information.

An example:

www.radiocom.net/vx6/nav1.htm

The math:

www.theairlinepilots.com/forum/viewtopic.php?p=971&sid=..

Hope this helps,

[mkonareff]

Hi Tom,

Thanks for your answer.

Indeed the B377 was not a good example!
In fact I would like to fly the Air France Paris-Tokyo polar route with a Starliner but I was thinking to make some training flights on a B377, which is not possible as you said.
The Starliner does have a PPC gauge but it does not simulate fully the instrument so I still need to find a solution to fly true headings or grid headings.

I already know a bit grid navigation because I studied it a bit last year, but I really don't know how to apply that on a virtual flight and how to fly such routes on FS without a real printed chart and a gyro which indicates only Magnetic headings.

Flying a polar route requires to follow grid headings or at least true headings, but in FS our gyro compass allows us to follow magnetic heading only (except the great DC7 with the PPC gauge) and that's the point where I am lost.
I don't know how to follow the calculated tracks. Do I miss anything?

I have to say that I am not used to big magnetic declination which is near to 0 here in France ! 

Thanks for your help

[Dennis the menace]

I think from what I have read, the closest any Strat got to the North Pole was a C-97 flying generators and heavy equipment into Thule AFB in Greenland. And that would have just been a northernly route straight up from Dover or McGuire via Goose Bay. As far as scheduled passenger service routes up north, it would have to be Northwest's Stratocruiser flights from Seattle to Tokyo via Anchorage (Elmendorf Field).  That would be flight 801 "Oriental Express Stratocruiser" in September 1952.

For some odd reason, they weren't stopping at Shanghai or Seoul anymore.....

[Tom/CalClassic]

Hi,

As seen in the Math link I gave above, it takes some real knowledge to convert from a grid reference to a true heading. You cannot use magnetic headings in this area.

The way I do it is plot an FS or FSNav flight plan (giving the great circle route between two points), and use the PPC to follow that course line (manually). I use as my end points the start and end of the "polar" portion of my flight. Without a real navigator doing the math I don't know of another way?

[mkonareff]

Hi Guys,

Thanks for your help.

@tom :

If I understand correctly, you do not use Grid navigation calculations, and use only true track that you follow with the douglas PPC, so from time to time you have to change a bit the true track you are following. Is that correct?
But I did not understand what you plot on FSNAV?
Also I tried to get the True Track in FSNAV by adding the North Pole as a bearing point but it does not work, FSnav gives the Mag heading only, so how do you get your true tracks ? I guess that you export your flight plan in the fs format which gives also true tracks.

And by this way of flying a north route, it is impossible to follow it with the Starliner of which PPC uses magnectic headings or with any other aircraft which does not have a PPC like in the douglas panels, no?

I have put in attachements one of the polar route I would like to follow with a starliner, I would really appreciate if you could help me a bit. I am a bit lost, I think I am missing something in your explanation, probably because of the language barrier.

[Tom/CalClassic]

Hi,

No, I do not use true headings at all. I open the FS or FSNav flight plan every 10 or 15 minutes, check if I am left or right of course, and estimate a heading change (i.e. the number of degrees left or right of my current course) that will bring me back on course in the next 10 or 15 minutes. Then I fly on until my next check. It's as if the navigator is taking position shots every 10 or 15 minutes and then giving me a new course each time.

[Defender]

Hi Maxime,

When Tom produced the PPC gauge I added it to my Starliner panel and flew the Paris -Anchorage route a few times based on the Flight Global article.

It was quite a while ago but I recall it worked using as Tom suggests a flight plan with very short sectors between waypoints, particularly when north of 65N. Here's one I used, created on FSNav. This is the FS9 export version which you can paste into a text doc adding suffix .PLN. Apologies, but a few of the waypoints are historic beacons I've added and not in the default FS9 but it seems to work anyway because the coordinates are there.  

Let me know if you need anything else. I could send you the FSNav version.

Bill  

[flightplan]
title=LFPO to PANC
description=LFPO, PANC
type=IFR
routetype=1
cruising_altitude=18000
departure_id=LFPO, N48* 43.41', E2* 22.79', +000291.99
departure_position=26
destination_id=PANC, N61* 10.46', W149* 59.78', +000150.92
departure_name=Orly
destination_name=Stevens Anchorage Intl
waypoint.0=LFPO, A, N48* 43.41', E2* 22.79', +000291.99,
waypoint.1=Fix01, I, N48* 41.08', E2* 10.08', +000000.00,
waypoint.2=RBT, V, N48* 39.24', E1* 59.65', +000000.00,
waypoint.3=PO, N, N48* 54.52', E1* 55.93', +000000.00,
waypoint.4=GI, N, N49* 50.53', E2* 29.06', +000000.00,
waypoint.5=KOK, V, N51* 5.68', E2* 39.10', +000000.00,
waypoint.6=SBH, N, N59* 52.94', W1* 17.69', +000000.00,
waypoint.7=LIRKI, I, N61* 0.00', W1* 51.00', +000000.00,
waypoint.8=6505N, I, N65* 0.00', W5* 0.00', +000000.00,
waypoint.9=6910N, I, N69* 0.00', W10* 0.00', +000000.00,
waypoint.10=7214N, I, N72* 0.00', W14* 0.00', +000000.00,
waypoint.11=7520N, I, N75* 0.00', W20* 0.00', +000000.00,
waypoint.12=7830N, I, N78* 0.00', W30* 0.00', +000000.00,
waypoint.13=8040N, I, N80* 0.00', W40* 0.00', +000000.00,
waypoint.14=8150N, I, N81* 0.00', W50* 0.00', +000000.00,
waypoint.15=8270N, I, N82* 0.00', W70* 0.00', +000000.00,
waypoint.16=8280N, I, N82* 0.00', W80* 0.00', +000000.00,
waypoint.17=8284N, I, N82* 0.00', W84* 0.00', +000000.00,
waypoint.18=8285N, I, N82* 0.00', W85* 0.00', +000000.00,
waypoint.19=8286N, I, N82* 0.00', W86* 0.00', +000000.00,
waypoint.20=8287N, I, N82* 0.00', W87* 0.00', +000000.00,
waypoint.21=Fix02, I, N81* 49.17', W95* 0.19', +000000.00,
waypoint.22=Fix03, I, N81* 37.92', W100* 0.13', +000000.00,
waypoint.23=Fix04, I, N81* 22.12', W105* 0.58', +000000.00,
waypoint.24=81N10, I, N81* 0.00', W110* 0.00', +000000.00,
waypoint.25=Fix05, I, N80* 43.83', W112* 59.82', +000000.00,
waypoint.26=Fix06, I, N80* 23.97', W116* 0.03', +000000.00,
waypoint.27=80N19, I, N80* 0.00', W119* 0.00', +000000.00,
waypoint.28=79N25, I, N79* 0.00', W125* 0.00', +000000.00,
waypoint.29=78N29, I, N78* 0.00', W129* 0.00', +000000.00,
waypoint.30=76N35, I, N76* 0.00', W135* 0.00', +000000.00,
waypoint.31=74N39, I, N74* 0.00', W139* 0.00', +000000.00,
waypoint.32=72N42, I, N72* 0.00', W142* 0.00', +000000.00,
waypoint.33=BTI, N, N70* 7.84', W143* 38.63', +000000.00,
waypoint.34=FTO, N, N66* 34.80', W145* 12.77', +000000.00,
waypoint.35=CUN, N, N64* 50.32', W147* 29.71', +000000.00,
waypoint.36=UMM, N, N63* 19.69', W149* 7.84', +000000.00,
waypoint.37=BGQ, V, N61* 34.17', W149* 58.03', +000000.00,
waypoint.38=CF14, I, N61* 17.70', W150* 4.09', +000000.00,
waypoint.39=PANC, A, N61* 10.46', W149* 59.78', +000150.92,
  

[mkonareff]

Hi guys,

Thanks again for your help, I really appreciate 

Tom, you are right, it is a good way to simulate the navigator reports, I will try that also.

Bill, do you mean that you have installed the PPC of the douglas panels into the Starliner panel?
It could be a good idea to follow true tracks or grid tracks with the Starliner... I will take a look at that if it does not need any complex modification.

Thanks also for the flight plan which will help me to understand better how to plan a flight like this one, I would be interested by the FSNAV plan if you still have it.

Cheers,
Maxime.

[Tom/CalClassic]

When I installed it, I just put the files from the DC-7 in a folder called CalClassic (in the Starliner's Panel folder):

Into the main 2D panel:

gauge43=CalClassic!Polar_Path_1, 588,500,189,90

and the VC:

gauge53=CalClassic!Polar_Path_1, 459,725,235,104

Include all gauge and bmp files starting with polar_path, and WARN_LIGHT_YELLOW.bmp.

[mkonareff]

Thanks for the tip Tom, I will try it shortly.

[Defender]

Maxime,

If you send me a PM with your email address I can give you my FSNav version.

Tom,

I notice my Starliner PPC gauge is POLAR_PATH_L1649.xml. I can't remember why it's different but I'll check our previous exchanges tomorrow.


Best regards

Bill
   

[mkonareff]

Okay Bill, I just sent you a PM

Now I think I have almost everything to fly along polar routes. May be I will have some few questions again but I think now it is okay.

Here is a small summary just to be sure I have understood everything correctly :

• For Polar flight without Polar path compass : The navigation is done with VORs and magnetic tracks until it is not relevant anymore then the navigation is done by Celestial navigation and dead reckoning with a classic gyro indicating magnetic headings. It is feasible on a route like Seattle to Tokyo with the B377 like Dennis The Menace said.
• For Polar flight with a Polar Path Compass : The navigation is done with VORs and magnetic tracks until it is not relevant anymore then the navigation is done by maintaining true headings or grid headings with the PPC and we can crosscheck our position with a sextant. It is feasible with the DC-7 and Starliner equipped with a PPC.

Best,
Maxime.

[warbaby]

I have Amelia Earhart's L-10, and it has a working flight computer, drift guage, and a sextant. That might be beneficial for a flight like this.

[Tom/CalClassic]

Hi Bill,

I don't know if I ever got a different PPC gauge from you, not sure about that. I can't find one, other than the DC-7 version. Did you ever make it available?