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Timothy
Timothy
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If I do a relatively long East/West leg (yesterday was Biggin to Exeter, for example) if find that the line on SD is significantly displaced from that on the plumbed in GPSs (530/430/Pilot IIIc) to the extent that there is probably over a mile between them at the mid point. Thus, one can have a significant fly right on one and fly left on the other.

Is this because the GPSs use GC and SD rhumb?

I think that the standard is GC. This could cause an issue tracking an airway centreline, I guess.
Edited 10/15/2012 10:30:18 AM by Timothy
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ckurz7000
ckurz7000
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Excuse me but this discussion is largely theoretical.

1) In 99.9% the difference between rhumb line and GC track is not an issue.

2) In those cases where it might be you can always put intermediate points on the GC track and approximate the GC course by several rhumb line legs.

So we are talking about the 0.1% cases for which the work-around solution is impractical.

-- Chris.
Timothy
Timothy
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I agree it is theoretical.

It's just a question of industry standard, how aeroplanes fly, how radio aids propagate and how all aviation GPS' are designed.

For example, SD could never be RNP certified, for exactly the reason 2high2fastagain gives.

There are more important things for Tim to focus on, such as getting all the airway centrelines in the system, even 3D SIDs and STARs, but that doesn't mean that it shouldn't be mentioned, just to sit on the back burner and simmer.
2high2fastagain
2high2fastagain
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Timothy - LOL - I'm sure you know what I mean! Try 'short hops from airport to airport anyway' instead.

In terms of that big crossing, I'd concede it would cost a few bob to hire the two Queen Elizabeth aircraft carriers (when they are finished) and to strategically position them as refueling stations for that weekend trip to Bangor Maine (and we'd be the only aircraft on them LOL)

Yes, this is a theoretical thread and I completely agree there are more important things for Tim D to do, but nonetheless it's still interesting.

The thread drew my attention as I would like to attempt the Atlantic Crossing one day (perhaps to fly into Oshkosh). Timothy, I'd go via Iqaluit as well with a thumping great ferry tank in the C182, though my routing would be Wick, Reykjavik (BIRK), Kulusuk, SondreStrom, Iqaluit and then down through Canada. Having worked in Greenland and seen the spectacularly rapid weather changes, my criteria would be that I would like to have enough fuel to go back to where I came from or even further back if the fog rolled in (I'm a project manager not an adventurer). But that discussion is one for another forum.

In terms of constructive advice for Tim D. Perhaps if someone puts in a very very very long track, a gentle warning that you are getting a rhumb line would be an ample response from Skydemon, but I wouldn't stick it at the top of any lists.
Timothy
Timothy
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2high2fastagain (07/11/2012)
I'm sure you know what I mean! Try 'short hops from airport to airport anyway' instead.
I think you are missing my point. How many airports are there on either of the tracks you have drawn?

My longest single flight not passing a single airport was 1385nm, though it has to be said that the GC coincided with the rhumb on that one Laugh
2high2fastagain
2high2fastagain
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None of course, which is why I at least, would take short hops across the northern route in a single.


Richard747
Richard747
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I would like an option for SD to display the GC, the Plog to show Initial True/Mag Track and a changing en-route track required to follow the GC. Thanks.
GO

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Timothy - 10/15/2012 10:29:59 AM
ckurz7000 - 10/16/2012 1:00:11 PM
Timothy - 10/16/2012 1:20:28 PM
Tim Dawson - 10/18/2012 1:00:43 PM
ckurz7000 - 10/18/2012 5:31:47 PM
Tim Dawson - 10/25/2012 3:53:26 PM
Timothy - 10/26/2012 9:15:09 AM
Timothy - 10/28/2012 12:33:43 AM
Tim Dawson - 10/30/2012 10:30:19 AM
Timothy - 10/30/2012 6:18:02 PM
2high2fastagain - 11/6/2012 8:42:50 PM
Timothy - 11/6/2012 11:03:28 PM
ckurz7000 - 11/7/2012 9:04:54 AM
                         I agree it is theoretical. It's just a question of industry...
Timothy - 11/7/2012 11:08:14 AM
                             Timothy - LOL - I'm sure you know what I mean! Try 'short hops from...
2high2fastagain - 11/7/2012 11:46:14 AM
                                 [quote][b]2high2fastagain (07/11/2012)[/b][hr]I'm sure you know what I...
Timothy - 11/7/2012 5:31:40 PM
                                     None of course, which is why I at least, would take short hops across...
2high2fastagain - 11/8/2012 8:44:41 AM
                                         I would like an option for SD to display the GC, the Plog to show...
Richard747 - 12/12/2013 5:52:21 PM
Tim Dawson - 12/13/2013 12:14:26 PM
Richard747 - 2/14/2014 10:43:53 PM

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