A really weird one, PAW grabbed traffic and held it.

[PeterG]

I had a similar thing coming back from France recently. One aircraft stayed close all the way back across the channel.

But I ran the track file through the viewer and the aircraft was dropped soon after takeoff. Is this an issue with the way SD handles things?

[Admin]

I need a track file to determine if we have latched traffic or not
Thx
Lee

[GeoffreyC]

Hi Lee

I’ve had an experience of “latched” traffic on playback.   I very rarely play previously recorded tracks but I needed to look at this one, but when I played it back, fast forwarding to the interesting bit, I found that a ground station and another plane had got “latched” to me.

Couldn’t work out how to attach the file to a pm so uploaded to box and sent you a link.

Cheers Geoffrey

[Admin]

Thats great, I will take a look
Thx
Lee

[jollyrog]

I've had this twice. Once a month ago and  friend flying in loose formation with me had exactly the same, with the same "latched" traffic. Had it today too, on the way to Rougham. A C152 with Mode S only, red ring, sat with me all the way.

[Ian Melville]

Rog,
That just sounds like there was another aircraft following your route?
Red ring (other colours available  ) will always be centred on your aircraft.

[GeoffreyC]

Rog,
That just sounds like there was another aircraft following your route?
Red ring (other colours available  ) will always be centred on your aircraft.

There's definitely a pattern of this issue because it happened to me today from Lee on Solent back to Sandy.   In the circuit I noticed that GAWPW was above and behind me, but ‘stuck’ a constant distance behind, and apparently flying backwards!
En route realised that there was GMISJ, GKEVH and GCECL also stuck.  GCECL was one of our group and according to my pilot aware he was flying through Southampton’s airspace at 0mph but 4000’ up.

GCECL eventually disappeared but I gained GCKDE.

Some screen shots and traffic captures below.  Interestingly GCIJO and GCIGG are both appearing as zero km away, they were flying with me but not that closely!  GCECL who was also with us is reported as 52km away.

When I finished the flight I turned off paw then turned it on again to download the track file; but found that nothing had been saved from this flight.  Prior two flights today both logged ok.

Geoffrey

Ps: unable to upload the photos as they were too big, and after I’d shrunk them I found that the forum wouldn’t allow .jpeg uploads, only .jpg.
Here they are therefore in Dropbox https://www.dropbox.com/sh/rdnh4tuol2c8rny/AABF7_YMw8MHrZeq9UxVUDoma?dl=0

 

[jollyrog]

Ian,

No, it wasn't traffic following me, it was a defect.

The first time I noticed this, a friend and I were flying from Turweston to Redhill. We both had the same latched aircraft. I recycled my PAW enroute and the latched traffic disappeared. My friend didn't and it was still on his at Redhill. There was no third aircraft, the latched traffic was something in the circuit at Turweston when we left.

[Admin]

Hi Lee

I’ve had an experience of “latched” traffic on playback.   I very rarely play previously recorded tracks but I needed to look at this one, but when I played it back, fast forwarding to the interesting bit, I found that a ground station and another plane had got “latched” to me.

Couldn’t work out how to attach the file to a pm so uploaded to box and sent you a link.

Cheers Geoffrey

Hi Geoffrey
Thanks for this, I loaded this into aircrew, and I do not see any latched traffic, are you only able to see this when you perform playback via SD ?

Here is the aircrew playback
https://aircrew.co.uk/playback/1094fe

There is an aircraft G-DYNA, which flies a parallel path - definitely not latched as its relative distance changes.
the fact that it is also pointing North looks like a transponder track error - we have seen this a lot on the Funke transponders

Can you indicate a time I should look at ?

Thx
Lee

[Admin]

Ian,

No, it wasn't traffic following me, it was a defect.

The first time I noticed this, a friend and I were flying from Turweston to Redhill. We both had the same latched aircraft. I recycled my PAW enroute and the latched traffic disappeared. My friend didn't and it was still on his at Redhill. There was no third aircraft, the latched traffic was something in the circuit at Turweston when we left.

Roger, can you supply the track file, this will allow us to investigate.
power cycling PAW would not necessarily indicate the latched data was from PAW, because SD would also clear its cache of aircraft as it lost connection.
a track file will help to determine.
Thx
Lee

[Admin]

En route realised that there was GMISJ, GKEVH and GCECL also stuck.  GCECL was one of our group and according to my pilot aware he was flying through Southampton’s airspace at 0mph but 4000’ up.

GCECL eventually disappeared but I gained GCKDE.

Does GCECL also have a transponder in addition to PilotAware ?
if so do you know the manufacturer ?

Some screen shots and traffic captures below.  Interestingly GCIJO and GCIGG are both appearing as zero km away, they were flying with me but not that closely!  GCECL who was also with us is reported as 52km away.

This is more interesting. I notice you have vertical/horizontal filters selected. This is only really intended for systems such as skymap which does not have filters available, in SD, it has its own filters. So I am wondering if something screwy is happening with filters applied.

Thx
Lee

[PeterG]

Attached the Track log from my cross channel flight and 3 screenshots from SD showing 2 aircraft (N95GT and f-GYKL) locked into the same relative position across the flight. The Aircrew track does not show this,

On another point. When you replay the track, which I did to get these images, the replay will pick up aircraft that are about now. For example on one image it shows an aircraftwithin close range - in fact it was sitting on the apron in front of me when the replay was running.

[exfirepro]

On another point. When you replay the track, which I did to get these images, the replay will pick up aircraft that are about now. For example on one image it shows an aircraftwithin close range - in fact it was sitting on the apron in front of me when the replay was running.

Peter,

This is a known phenomenon - if you replay PAW track files on PAW, it treats the track data as if it was ‘live data’ and if it is also receiving external data from it’s antennae, it will parse (combine) this and pass the combined data to the Nav Display. I don’t think this is what Geoffrey and the others are experiencing though as the initial reports are of apparently latched aircraft ‘in flight’ not during replay.

Regards

Peter R

[exfirepro]

Lee,

Strange that no Track Log has been created for this flight in Rosetta which would have allowed analysis.

From Geoffrey’s post yesterday, he seems to be reporting this as occurring ‘live’, during flight, which is indeed very strange - as from yesterday’s screenshots GAWPW clearly seems to be maintaining a relationship with Geoffrey’s ‘Ownship’ yet doesn’t appear in any of his Traffic Table screenshots at all.

This reminds me of a similar effect which if you remember Ian Corse from Perth experienced with latching PilotAware and Mode-S signals from the same aircraft back in February 2018 with Version 20180129 and which from my notes you fixed in Eng. Version 20180212. IIRC Ian’s plane was initially receiving both P3i and Mode-S direct from the other aircraft then lost the P3i signal due to separation, but PAW latched the last known P3i position to the Mode-S report. Could this be something similar?

Regards

Peter

[Admin]

Attached the Track log from my cross channel flight ...

Hi Peter
I do not see any attachemnts. If they are too large you will need to use dropbox/googledrive or similar
Thx
Lee