Traffic data labels with swapped origin and destination

[somiller]

There seem to be many flights that have clearly swapped/reversed origin and destination. I posted this issue in the LNM forum and Alex confirmed that LNM simply reads the data using simconnect and that the bad data must be coming from RT. Is there some reason why this can't be corrected? I spotted traffic in RT and couldn't find a single flight with obviously swapped origin and destination - I suppose it's possible I didn't look at enough aircraft, but in MSFS/LNM it seems that maybe up to 1/3 have origin and destination swapped.

Another data label issue that is annoying is ground speed (or maybe it's not ground speed but rather true airspeed) for airliners at cruise almost always shows as 429 kts, for every aircraft at every cruise altitude regardless of winds. When I look at the data on RT for airliners at cruise it shows believable speeds, which I assume are ground speed. Examples in RT:

FDX1217 is flying west-southwesterly 399.1 kts clearly against headwinds

 

AAL1360 is flying northeasterly 521.3 kts probably with a bit of a tailwind

 

GTI4312 is flying north-north westerly 393.8 kts again probably into a headwind

[kiek]

5 hours ago, somiller said:

 Is there some reason why this can't be corrected? 

 

PSXT passes origin and destination coming from RT info 1-> 1 to SimConnect.
It often occurs that RT changes that info on the fly, and then PSXT replaces the complete aircraft in the Sim in order to make that change visible in LNM too, but only if you have checked GUID changes in the PSXT UI.

However, there are still a lot of flights without orig/dest info or wrong info. PSXT cannot change that, the problem lies in the sources RT is using. 

5 hours ago, somiller said:

Another data label issue that is annoying is ground speed (or maybe it's not ground speed but rather true airspeed) for airliners at cruise almost always shows as 429 kts, for every aircraft at every cruise altitude regardless of winds. When I look at the data on RT for airliners at cruise it shows believable speeds, which I assume are ground speed.

PSXT only puts the TAS in SimConnect. If you see -1 in RT it means that TAS is not available. What LNM makes of it, I don't know, I have not paid attention to it sofar.

[somiller]

I do and have always had GUID checked in the PSXT UI since that option was added.

Nico is it possible to send ground speed to simconnect rather than TAS?

[kiek]

1 hour ago, somiller said:

Nico is it possible to send ground speed to simconnect rather than TAS?

That is possible, but I'm reluctant to do that because it costs PSXT cpu cycles that have no meaning in PSXT. Remember, for each aircraft at each frame writing that data...

TAS is written because, for some strange reasons, it makes AI aircraft wheels on the ground cycle according to the ground speed.

You must know that on the ground, TAS is equal to the groundspeed (something PSXT does). And if there is no TAS in RT, PSXT fills in some "reasonable values" depending on height.

Maybe I should try to always give TAS the value of the groundspeed....

(hope you could follow me 😉 )

[somiller]

"Maybe I should try to always give TAS the value of the groundspeed...."

Interesting idea which would avoid any issue with aircraft wheels on the ground.

TAS is rarely exactly the same as ground speed even when on the ground - TAS airspeed is independent of winds. An aircraft on the ground with a ground speed of 100 kts with a 30 knot headwind would be at a true airspeed of 130 kts. An aircraft at 100 kt ground speed at 30,000 feet with no wind would be at a TAS of 100 kts. The difference between TAS and ground speed is only a function of wind, and we would all agree there can be wind on the ground.

 

[kiek]

2 hours ago, somiller said:

TAS is rarely exactly the same as ground speed even when on the ground - TAS airspeed is independent of winds. An aircraft on the ground with a ground speed of 100 kts with a 30 knot headwind would be at a true airspeed of 130 kts. An aircraft at 100 kt ground speed at 30,000 feet with no wind would be at a TAS of 100 kts. The difference between TAS and ground speed is only a function of wind, and we would all agree there can be wind on the ground.

 

But for LNM purposes it does not matter, the aircraft position is set by PSXT, TAS or GS have no real meaning in that.

EDIT: In LNM I see groundspeed displayed although PSXT is not giving that info.  Does LNM try to fill that in based on position changes?

Edited January 10 by kiek

[somiller]

7 hours ago, kiek said:

But for LNM purposes it does not matter, the aircraft position is set by PSXT, TAS or GS have no real meaning in that.

EDIT: In LNM I see groundspeed displayed although PSXT is not giving that info.  Does LNM try to fill that in based on position changes?

That's a good question. I wonder if LNM is calculating ground speed from TAS and winds? I'll ask on the LNM forum.

I am viewing AI in LNM and have LNM data labels set to IAS, TAS, and GS. A flight at 37,000 ft. shows IAS 229, GS 429, and TAS 430. Another flight at 34,000 shows IAS 243, GS 429, and TAS 430. These aircraft demonstrate the issue...it seems ALL airliners/jets at cruise altitudes have the same TAS and GS regardless of winds or altitude which can't be correct. GS should vary from TAS by prevailing winds. It appears that LNM is simply making GS match TAS. In real life GS and TAS would rarely match and depending on winds could vary by 10's or even 100 kts or greater.

Without Alex actually running PSXT/RT and looking at the simconnect data for PSXT injected aircraft I don't know how it would be possible to determine what is being presented for IAS, GS, and TAS in LNM.

In any case the speed data for jets at cruise altitudes presented in LNM from the simconnect data provide by RT is mostly worthless except for maybe IAS.

[kiek]

53 minutes ago, somiller said:

That's a good question. I wonder if LNM is calculating ground speed from TAS and winds? I'll ask on the LNM forum.

You should also remind him, that PSXT's aircraft are not controlled by the MSFS AI engine, but just plain aircraft objects, shifted through the skies by PSXT 😉 

[somiller]

Nico,

In the thread I started on LNM forum regarding swapped origin and destination Alex replied with: "LNM fetches the same fields using SimConnect since FSX times already"

Does that mean anything to you? I have practically no knowledge of simconnect data format.

[kiek]

Yes, what we already knew that the problem is not LNM, not PSXT but RT. These aircraft are making a return flight but the orig dest are still for their inbound flights...errors in the data source.

 

[somiller]

45 minutes ago, kiek said:

Yes, what we already knew that the problem is not LNM, not PSXT but RT. These aircraft are making a return flight but the orig dest are still for their inbound flights...errors in the data source.

 

I'm not understanding how a return flight could still retain data from a previous flight. Certainly the aircraft is not transmitting origin/destination data from a previous flight which is then pickup up by ads-b receivers. It seems to me the ONLY way this could be possible is that for some reason the origin/destination portion of the ads-b data is not being refreshed by RT at the same rate as say location, heading, speed etc. - which may also explain why a meaningful number of commercial aircraft flights from RT show no orgin/destination (although I also see flights with missing origin/dest but never swapped on Flightaware and Flightradar24).  If it's a refresh issue clearly it isn't working as intended.

I've emailed Balt to see if he can provide some clarification about these issues.

[kiek]

13 hours ago, somiller said:

I'm not understanding how a return flight could still retain data from a previous flight. Certainly the aircraft is not transmitting origin/destination data from a previous flight which is then pickup up by ads-b receivers. It seems to me the ONLY way this could be possible is that for some reason the origin/destination portion of the ads-b data is not being refreshed by RT at the same rate as say location, heading, speed etc. - which may also explain why a meaningful number of commercial aircraft flights from RT show no orgin/destination (although I also see flights with missing origin/dest but never swapped on Flightaware and Flightradar24).  If it's a refresh issue clearly it isn't working as intended.

I've emailed Balt to see if he can provide some clarification about these issues.

Balt is dependent on the data providers he has contracted.

If they provide bad data, what they often do unfortunately, he cannot do much about it, other then searching for better data providers (edit: but they cost a lot ore money I'm afraid).

 

Edited January 11 by kiek