Primarily for general aviation discussion, but other aviation topics are also welcome.
#1870686
Ibra wrote:I was referring to arrival time which is more headwind component, how accurate this was? or things were relaxed “will be there early afternoon”


Speaking personally, it tended to work out within 30 seconds for me.

It was better than I currently do with GPS! ;-)
By Ibra
#1870702
Paul_Sengupta wrote:
Ibra wrote:I was referring to arrival time which is more headwind component, how accurate this was? or things were relaxed “will be there early afternoon”


Speaking personally, it tended to work out within 30 seconds for me.

It was better than I currently do with GPS! ;-)


With CV19 restaurant table booking time you won’t miss you lunch slot :lol:
#1870749
Tim Dawson wrote:
lobstaboy wrote:Do today's military use Skydemon?


Many militaries use SkyDemon, yes.


;) very good Tim. I apologise for my imprecise language. What I meant was, would today's RAF or USAF use Skydemon operationally on a mission needing the highest accuracy and resilience against hostile interference as their primary navigation tool?
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By MattL
#1870751
@lobstaboy you are talking about system integrity there which is about far more than an app - you would be into GNSS source, hardware, air vehicle integration, EMC/EMI etc
#1870754
MattL wrote:@lobstaboy you are talking about system integrity there which is about far more than an app - you would be into GNSS source, hardware, air vehicle integration, EMC/EMI etc

Yes I know. It was a rhetorical question...
SD is lovely. Even theFarmer uses it! But it is not the holy grail.
#1870758
would today's RAF or USAF use Skydemon operationally on a mission needing the highest accuracy and resilience against hostile interference as their primary navigation tool?


That would probably be a secret. But I'd imagine even if they did use this, they'd need to closely vet all their hardware and software to make sure there are no backdoors for transmitting their plans and current locations to anyone not authorised to read it.
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By kanga
#1870817
lobstaboy wrote:.. Do today's military use Skydemon?


In the 1930s the Air League promoted a scheme whereby cities and town in UK could 'adopt' a RAF Squadron, often one then based locally. The Borough of Cheltenham 'adopted' 57 Sqn, then based at Upper Heyford (with Hawker Harts).

When 57 disbanded as a Victor Sqn at RAF Marham in 1986, I got permission to fly (a Cherokee) carrying the Deputy Mayor (RAF veteran, former Hurricane Fitter in Burma; work colleague and my local Councillor) up for the disbandment ceremony, to 'fly the Borough flag' (actually, it was draped over the cowling when I got there, IIRC). All other visiting aircraft were military, nearly all jets. I was given a 5 minute arrival 'slot'. This was quite challenging (for a strictly VFR bimbler) before any electronic aids and no very close ground-based navaids (ISTR we had an ADF and possibly VOR, but no DME). Fortunately, my Air Cadet instructor colleague was in RHS, and had just come off the Air Cadet Instructor's Nav course (done at Finningley, IIRC), and helped with the Plog, headings and ETAs. Somehow we made the time slot, with a late slowdown .. I'm sure the Marham SATCO had thought the request quite reasonable, as any of the military types flying in (most with Navs) would have found it trivial :?

Good day, and it was gratifying for the Councillor how many visitors stopped on the flight line to ask why we were there. It was also the first time he'd ever been, let alone eaten as a named VIP guest, in an Officers' Mess :)
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#1870888
Ibra wrote:
Genghis the Engineer wrote:
Ibra wrote:One thing that has changed when doing old nav today is the quality of wind forecast on long legs, you can really get it down to ETA+/-5min, I wonder how accurate this was in the old days?


We didn't in the "old days" assume the wind forecast was accurate, we used it for an initial heading, then refined it as we established our variation from track.

G



I was referring to arrival time which is more headwind component, how accurate this was? or things were relaxed “will be there early afternoon”


But exactly the same applies.

You give your best initial estimate for the right heading and predicted groundspeed, then use waypoints to tell you how much reality varies from your predictions. From that you revise predictions of groundspeed and drift, correct, carry on.

But anybody who has done a PPL since WW2 knows that of-course.

I'd say that once I'm past halfway, my ETA is usually within a minute, and within two minutes past my quarter way point so long as the leg is less than a hundred miles or so.

G
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#1870923
I started flying in 2005 and have never flown without GPS (excepting my FAA/JAA training and check flights). That's 21 years of following the magenta line and for all the talk of "what it it doesn't work" - it always has.

Electronic moving maps have been around since the early 2000's, yet many speak of them as if they're a new development.
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By Rob P
#1870972
Of course the earliest moving maps were greyscale, so we had to wait for the arrival of magenta.

I do recall a time using my Pilot3 to navigate across France flying very neatly down an airspace boundary rather than the magenta (grey) proposed track.

Rob P
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#1870975
RisePilot wrote:I started flying in 2005 and have never flown without GPS (excepting my FAA/JAA training and check flights). That's 21 years of following the magenta line and for all the talk of "what it it doesn't work" - it always has.

Electronic moving maps have been around since the early 2000's, yet many speak of them as if they're a new development.


I got my PPL in 1993: The first GPS I bought was c 1996 IIRC which was a Garmin GPS90. with a screen the size of a' large letter' 1st class postage stamp.

I remember trying it for the first time walking around the back garden and being gob-smacked watching the icon move when I only walked a coupla yards...........

I must admit for long journeys I doubled it up with the trusty Narco RNAV for a coupla years as I didn't really trust it.

I even bought a Pilot 3 with a US Basemap which saw Keef and I succesfully around the West Coast on our numerous jaunts in the early noughties........
Only marginally bigger screen than the 90 and still grayscale.......

After that I bought a Garmin 295 which though colour was as heavy as a house brick and was too heavy to go on the yoke: Eventually sold it to a forumite and replaced it with the lighter 296.- which I still use today as my quadruple navigational back up. :wink: