Question for DME UPDATING:

Every flight during first 150 nm of Flight Plan, INS gradually starts to loose signals.It goes to 9 from 0. I establish  "DME Position Updating".
Signals slowly goes back to "0". Then during the next 150nm, it starts all over again, signal slowly goes back to 9.

Is this a normal INS procedure ? (I dont think so.Otherwise just fly VOR to VOR)
Do I need to do DME Updating always?

Thx

Hey, guys, I've just received the approval for attaching those mentioned panel.cfg files to my tutorial post.
So if you don't want to go through all the manual steps for installation, just load that small package and pick the right cfg file. Just surf to page 1 of this thread and look for the "edited" box there.  
The all work for the corresponding variants if version 1.3 of the 707 is installed.

Sanal, seems like you are getting really interested in the Civa INS.  
First of all, you are right with your assumption, you will always have to update the INS because it's always losing its accuracy when the plane moves or shakes (which happens all the time after getting off the Gates).
So every time you don't update, accuracy slowly goes down (seems to depend on the actual shaking or course corrections made), while the opposite happens when you tune and set up a DME station for the update. So, in theory, you could tune one VOR when 200nm out, leave it there, overfly it and leave for another 200nm, getting 400nm of range and low workload.
So the best time to start updating is at the Gates. Choose the nearest DME VOR station, tune it, enter the coordinates and start updating just before engine start or taxi, so you are free for the next 100+nm if you like, and the units stay aligned.

For the update itself, you need some DME VOR in range, not necessarily one which is on your route, but in reception range which gives you around 200nm of possible radius. With two CDUs, you should chose one VOR which is on your route (you will overfly it) and one with an offset. You will see that the accuracy index then stays well within limits.
The green "Nav" light shows you that an accurate navigation is possible, which leads to an index of "5" as worst one, while "0" is best. Value 6 (which is too high) corresponds to 0.5 NM of error for example.
When you are using the Civa gauges together with the Update Flags, you will see if an update is in progress or not. You can see it on the CDUs too, but these flags are easier to read. If not, one has to check the error source there as this means that his units are losing accuracy now, instead of gaining it.


Here's what the OperationsManual states about updating.
Quote:


So, as you see, there's no need to plan your flights from VOR to VOR. I'm using my Civa equipped planes on all standard routes in US and European Airspace for example. So they mainly consist of Intersections, like they would do on the FMC aircraft. DME Updates take place when the workload allows it, so the final descent or the initial climb are not distracted by this procedure.

2-Do you just turn A/P mode selector to NAV?
That should do it in the 707. Make sure to switch to INS on the Doppler/INS switch too, and everything will be set. The INS then drives the HDG bug.
The FD should go to HDG then, showing you the way to the INS driven heading value.

To set the initial location on the INS, press 2/N the number then INSERT to enter the North co-ordinate, then 6/W the number then INSERT again to enter the West co-ordinate. e.g. To enter these co-ordinates, N33^o 56.33' W118^o 24.2'9 press 2/N, 33563, INSERT, 6/W 118242, INSERT.

Hope this helps.

Masrk

CoolP wrote on Mar 11^th, 2011 at 3:22pm:
Rats! And I thought I wrote Marsk.

You're welcome yallu.

Now for something I'm curious about:
Say I have a waypoint with these co-ordinates: S37^o 14.49' E144^o 29.24' - Would you enter them into the INS as S37144 E144292 or S37145 E144292? Because S37145 E144292 would put the INS location closer to the actual waypoint, rather than using 4, which is slightly further away. We can really do as we please, it's just that I put it as close to the waypoint as I can, so I would enter it as S37145 E144292.

Mark

I'm working like you too, Mark. The initial fix should be as accurate as it could be while the rest is done with the DME updates. We should operate as accurate as we can to allow the system to do it the same way.
If the accuracy at the end of the flight really reflects this whole investment? I don't know, but I hope so.  
You won't land at the wrong airport when picking the 4 instead of the 5 there though.  

By the way, did some of you ever land at the wrong one? I did once, but this wasn't a Civa flight. I laughed about this "incident" for quite some time when thinking about a real pilot acting like this.
"Oops, either they've rebuild the place since last week or I'm at the wrong place. However, lets act as if nothing happened".