Primarily for general aviation discussion, but other aviation topics are also welcome.
By VinceGod
#1856050
We have 3 aircraft flying together, one with pilotaware linked to transponder broadcasting PI3 & ADSB-17, another with SE2 broadcasting ADSB-18 & MLAT, and the third with just MLAT. A pilot of one aircraft reports strange or unexpected behaviour which could be could be caused by either the transmitting unit or receiving unit or a failure of MK1 eyeball. Why would anyone not want to understand and figure out what is happening or do people think their device is the best and can not be at fault?

Here’s a track of the 3 aircraft.
Image
#1856138
ls8pilot wrote:One oddity maybe someone can explain is that at one point the plot seems to show four tracks?


This is because there are multiple sources overlayed MLAT and DF17
I think we only need to concentrate on DF17 here - this is the only format visible by the OP using SE2 in this scenario, in this case the aircraft has the following DF17 track
This is the aircraft which I understand is being fed with the PilotAware GPS data
the altitude profile is at the bottom of the screen

Image

Thx
Lee
User avatar
By marioair
#1856145
I’ve in the past had some odd / unexpected pop ups on a SD/PAW combo. I suspect we’re all experiencing a knowledge and experience gap / combination of

1) diverse sources of raw data with different behaviours, failure modes etc
2) display/processing (PAW, SE2) that have subtle differences and different means of in flight and post flight diagnostics
3) more and more first hand demonstration of what we’ve always known - MK1 eyeball is fallible

Pilot training will take years to churn out pilots that ab initio understand these complexities.

But in the mean time I wonder whether we are at a inflexion point - we need to grow our confidence in un certified tech. There’s a real danger than word of mouth, forum speculation and old views harm adoption.

So how do we battle this? I really applaud, for example @leemoore1966 [usermention=16577]’s attempts to do a fault diagnosis. We do of course need to take this with a pinch of salt due to conflict of interest.

However I would personally love to see more PIREP style write ups about issues seen and then post flight diagnostics so we can understand what/why happened.

Is this something we could champion via Flyer? We have strong(read vocal) tribes from each vendor. Rather than sniping maybe a cross-vendor panel can be created to investigate PIREPs?
#1856233
The tracks shown on the screenshots are dead right as far as I can tell.
The anomaly is the timing of the lead aircraft in the East Wittering to Mayfield section.
As I posted originally; I took off 3rd of 3 and can never catch the lead aircraft - its faster.
I saw the other 2 go off up the Solent and out of sight, ahead.
Then mysteriously the lead aircraft is beside me ( details in op) on screen but not in reality ( according to me and my passenger anyway) and I gently manoeuvre to spot it, basically all the way to Mayfield, with no success.

My passenger has logged time in more aircraft than anyone I've ever known and flies every week at least; I bored him silly asking "can you see it?" and neither of us could, whatever I did.
Not proof I know, but it would be odd if neither of us could see a familiar aircraft half a mile away that I could pinpoint to a certain geographical position and height - over and over again for about 20 minutes.

The second odd thing, is the time me taken by the lead to get from Mayfield VOR to Crowborough/T Wells - on my screen- it seemed to be only a couple of minutes.

For what it's worth I think the boxes were 'catching up' at this point and from Crowborough onwards the track/time was correct.
Relative arrival times back at base support this.

I'm not blaming any particular bit of kit or system - it's all wonderful.
I'm only asking if it's happened before to anyone else and for a reasoned explanation.
By riverrock
FLYER Club Member  FLYER Club Member
#1856234
So if you track back on one of the systems above, and the lead aircraft in the system above is further from you than what you saw on your screen, the issue was your receiver / screen.
#1856298
@thegasguy @riverrock
Hi

Thanks for the updated information
I concur with @riverrock as far as the analysis is concerned
At no point during your flight was the lead aircraft (G-AYGG) anywhere other than in front of you

This would indicate either a traffic report error or GPS error on your device, ie

1. your receiver was telling you that G-AYGG was behind you when it was in fact in front of you

2. your receiver GPS was telling SkyDemon you were ahead of your real position, erroneously reporting G-AYGG as appearing behind you

The ground based tracking has G-AYGG always in the lead position

@Cub is there no post analysis or logging information capability that can be obtained from the SE2 to confirm what @thegasguy has reported here ?
Alternately does SD contain any traffic report logging ?

Thx
Lee
#1856367
Leemore1966:
I agree on lead 'reality' position - I could not have caught it.
The position beside, and more or less parallel track to me - on screen - is indisputable.
Seen by two of us, and a wide awake jolt to me as it was converging a little.
I was properly concentrating then, as it looked as if we would converge in a few minutes. No mistake about that.

I took a picture on my phone of the screen at one point, I'll have a look to see if it is of anything useful.

I have it, just north of Plumpton racecourse, I'm apparently just behind and 400' above.
I'll try to put it up now.
Image
By VinceGod
#1856417
The playback seems to match up with your screen shot!
Image

However there is a little loss of or corrupt data at this spot.
Image

This could be due to the ground stations at some distance or poor GPS signal / position on the PAW unit.
By DirkGently
#1856418
{{I was going to say}}:
thegasguy wrote:A rather odd experience yesterday flying back from Lee on Solent to our strip in North Kent.
I haven't ploughed through the responses, but, I think it's reasonable to ask:
What EC IN/OUT was being used by each aircraft.
What EC IN was giving the results of the strange readings.
What analysis of each ship's EC has been performed?
It reads like a Daily Mail expose. The facts are with the OP, it's ridiculous to speculate without full disclosure
Disclose, expound, enlighten us with facts. Try to reduce uncertainty with information. Don't invite uninformed speculation.

Or

Love Island. Voyeur Paradise
{{but I decided not to, as you were}}
#1856445
DirkGently;
A bit lazy to ask those questions while admitting you haven't read any of it!
Everything you ask is in the first few posts.

All the facts available are out there; no one is going to do any forensic investigation- I certainly don't know how to and don't want to, plus I have no access to other people's 'data'.

My original question- " anyone else seen this?" is all I'm interested in really.

If not, so be it and I'm off to spec savers.