Oh well, another concept completely ignored by flight simulator. Close to the poles you cannot fly normal headings, TRUE or MAG.... For flying on the poles you need to fly GRID. Normally you overlay a MErcator projection on the polar area you are flying in and convert your headings to grid headings. Complex and teeeedious topic.

For all those interested: http://boeing.com/co...olar_story.html http://www.smartcock...ps/navigation/7 http://www.smartcock...ps/navigation/8 It does exist for 737's. I'm just trying to find some documentation regarding the actual switch/system. Aside from a few ambiguous references in the IPC and the above docs I'm kickin' myself over this. I guess one just has to get Astrocompass out and start going' nuts...haha

Check out the FCOM Vol 2 page 541 !! Bottom of page !!

Yes that tells me that a True reference is possible, but mentions nothing of any automatic switchover. It doesn't switch over in the NGX...well...I haven't flown north of around 74 so well see. Ahh things much simpler with your old C6 Latitude compensating DG and good ol Astrocomp.

I'm going to bump this. I think we want to know where the physical switch is (If there is one), and not so much of when to use it. I'm still going crazy trying to find it. If there is not a switch, then is it automatic? If it's not automatic and there is no switch, then how do we get TRU heading?

Edited August 28, 201114 yr by NickC

To my knowledge,no airlines operating the NG have polar ops,I think your getting out of the realm of reality, Wait for the 777.

Wow, there is none...

So there is no switch on the real plane? Does change to true heading occur automatically then?

The switch is............................................................................................

The switch is............................................................................................

[Option - With HGS 2350 and polar navigation]Do not use HUD System at latitudes greater than 85 degrees latitude or when the Heading Reference Switch is in the TRUE position.

[Option - With HGS 2350 and polar navigation]Do not use HUD System at latitudes greater than 85 degrees latitude or when the Heading Reference Switch is in the TRUE position.

So there is a switch... But the question is where?

Polar navigation option.Boeing.com<These latitude limitations on flight operation do not apply to 747-400, 777, and 737-600/-700/-800/-900 airplanes equipped with the polar navigation option (heading reference switch and FMC Update U10.3 or later) >Boeing.com I have had a look in the 737 switches guide, and assuming the heading reference switch would be located on the IRS panel. The only switch documented and visable on the IRS panel relating to heading is the HDG/STA switch. NGX may not have the polar option ?

Would be nice to have some official word on this....

Oh well, another concept completely ignored by flight simulator. Close to the poles you cannot fly normal headings, TRUE or MAG.... For flying on the poles you need to fly GRID. Normally you overlay a MErcator projection on the polar area you are flying in and convert your headings to grid headings. Complex and teeeedious topic.

Do you know anyone who flies grid? And I always thought they'd just go -D-> NPOLE and continue... And after all, grid headings still just convert to usual headings...

Oh well, another concept completely ignored by flight simulator. Close to the poles you cannot fly normal headings, TRUE or MAG.... For flying on the poles you need to fly GRID. Normally you overlay a MErcator projection on the polar area you are flying in and convert your headings to grid headings. Complex and teeeedious topic.

+1I saw this on 747/400 (real) and PS1 747 simulator (GRID fully simulated) Regards, Richard Portier

Close to the poles you cannot fly normal headings, TRUE or MAG....

No, you should not be flying any headings but I think the standard procedure is simply to keep wings level, AP engaged but in a simple wings level mode (not sure about Boeing but in many other aircraft it is called a ROLL mode). Once you move away from the immediate proximity of the pole you switch to heading, LNAV or whatever you want.

Would be nice to have some official word on this....

+1

To my knowledge,no airlines operating the NG have polar ops,I think your getting out of the realm of reality, Wait for the 777.

I'm not necessarily talking about polar operations...ie: crossing the poles. But sometimes especially up here in Canada you may find yourself operating in airspace that requires a true reference - Northern Domestic Airspace. Although in reality you wouldn't see a NG running up there because of those low-slung CFM's and lack of a gravel kit - hence the -200's that remain prevalent today.

.2.1 Northern Domestic AirspaceCanadian Domestic Airspace is geographically divided into the Southern Domestic Airspace and the Northern Domestic Airspace as indicated in Figure 2.1. In the Southern Domestic Airspace, magnetic track is used to determine cruising altitude for direction of flight.The Magnetic North Pole is located near the centre of the Northern Domestic Airspace, therefore magnetic compass indications may be erratic. Thus, in this airspace, runway heading is given in true and true track is used to determine cruising altitude for direction of flight in lieu of magnetic track.