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DME updating (Read 37 times)
OZ flyer
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DME updating
Feb 26th, 2018, 7:25pm
 
ive been - for the first time - messing around with DME updating new feature. I’ve never seen the INS to be honest actually get that far off track with API on 9. I’ll often fly long hauls and it’s accurate anyway but i thought I’d do it to relieve the boredom. Cheesy

Question I had was, is it really necessary to update it every 45 mins when it goes from API 1-9 considering it will only be innacurate to perhaps a couple hundred metres at best on API 9?

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Marco Ravanello
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Re: DME updating
Reply #1 - Feb 26th, 2018, 8:02pm
 
> is it really necessary to update it

It depends on how realistically you want to manage it.
Crews would keep as many INS units in DME Update mode (as dual DME update is much better than single dme update) as long as they could.
Only exception were when flying:
- Over large water areas (oceans) (no navaids available) [any kind of updating is IMPOSSIBLE]
- When flying (especially at night) over Africa [only manual updating available if no VOR/DME available, so only ADF. For manual updating it would be sufficient to have the lat/long coordinates of a well visible geographical location but at night that's hard too]. I believe Africa was the only area when Manual Updating was used.

> I’ve never seen the INS to be honest actually get that far off track with API on 9

Maximum acceptable "displacement" is 3NM/hour. Such "displacement" (which in the real world is INU error) grows with time. The rate it grows is calculated "pseudo randomly" by INS gauges, so it could be quite different from flight to flight, and still within the 3 NM/h limit, but just "a couple hundred metres" sounds strange to me. How long was the flight (in terms of flight hours)?

Marco
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OZ flyer
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Re: DME updating
Reply #2 - Feb 26th, 2018, 11:11pm
 
All the flights I do are long haul - 6-10 hours in the RFP 747. I’ve flown it for years and never ever seen it be that far of track by the end of the flight. It always tracks where it should.
I only started doing it out of interest not because it flys off track. I’ve seen other simmers in forum posts when I researched say it’s not needed because it will always fly pretty accurately which I see from my experience.
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« Last Edit: Feb 26th, 2018, 11:12pm by OZ flyer »  
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Marco Ravanello
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Re: DME updating
Reply #3 - Feb 27th, 2018, 8:40am
 
That's because you're using Triple INS config and what you see is the result of TripleMix-ing. Try disabling it if you like drifting  Grin
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OZ flyer
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Re: DME updating
Reply #4 - Feb 27th, 2018, 3:16pm
 
AH ok. Makes perfect sense. Last flight - as I was typing above info - was 3800nm flight. By the end I noted where I flew over a waypoint/vor. With no updating it looked no more then .5nm away but let’s say 1nm. Which was pretty good.

I guess to accurately be at a waypoint the DME updating is important. I’ll certainky do this is future. It gives me more reason to pay attention in the cockpit.

And I’ll give the one unit a try next time. Smiley


Thanks though for a FANTASTIC add-on. I’ve never had issues and the odd random failure keeps you on your toes. Brings so much realism to ‘flying’.
Great job!
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Marco Ravanello
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Re: DME updating
Reply #5 - Feb 27th, 2018, 3:57pm
 
Correct, minimizing drift lets you be in the correct position, where controllers and other traffic expect you to be.

To see how much the unit would drift you could easily DISable TripleMixing in Triple INS configurations, try searching for "EXITING FROM TRIPLE MIXING OR DME UPDATING" within OperationsManual.pdf

Happy you like the CIVA  gauges, thank you!
Marco
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« Last Edit: Feb 27th, 2018, 6:35pm by Marco Ravanello »  
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