Hi Nico.

Not sure if this is related to PSXT or RealTraffic, but I'm experiencing a slow-motion effect seconds after takeoff of any aircraft. Also, I see that most aircraft are not banking on turns. All this is with version 15.6.4.

Thank you
Jaime
Monterrey, Mexico

Edited July 1Jul 1 by jcuellar

I saw that too yesterday, will investigate.

9 hours ago, jcuellar said:

I'm experiencing a slow-motion effect seconds after takeoff of any aircraft

I have seen this too.

15 hours ago, kiek said:

I saw that too yesterday, will investigate.

This is caused by bad RT data. I have made a change so that aircraft wait a little longer before rotating, hoping that valid airborne data will become available shortly. Please try 15.6.5
(btw that version also fixed a bug in the livery scan. Try that too, maybe you will get some more liveries).

Edited July 1Jul 1 by kiek

2 hours ago, kiek said:

This is caused by bad RT data. I have made a change so that aircraft wait a little longer before rotating, hoping that valid airborne data will become available shortly. Please try 15.6.5
(btw that version also fixed a bug in the livery scan. Try that too, maybe you will get some more liveries).

With version 15.6.5, the strange slow motion appears 3 seconds after takeoff.

6 hours ago, jcuellar said:

With version 15.6.5, the strange slow motion appears 3 seconds after takeoff.

Yes maybe. But not with all aircraft. Just watch a bit longer.

I have tested at EHAM and maybe 1 out of 8 departing aircraft slowed down a bit because of bad RT data.

What airport are you?

Edited July 2Jul 2 by kiek

1 hour ago, kiek said:

Yes maybe. But not with all aircraft. Just watch a bit longer.

I have tested at EHAM and maybe 1 out of 8 departing aircraft slowed down a bit because of bad RT data.

What airport are you?

I'll also test EHAM for just one hour; it is late here in Mexico. I'll give you my feedback.

Jaime

25 minutes ago, jcuellar said:

I'll also test EHAM for just one hour; it is late here in Mexico. I'll give you my feedback.

Jaime

I am also at EHAM now and I see no problems.

There has always been a small adjustment effect after take-off, because PSXT has to align the aircraft with the airborne RT data. During the take-off roll, PSXT overrides the RT data to achieve the required speeds. But that has been the case from the beginning.

EDIT: I recommend to use RT Direct, that gives slightly better results (data every 3 seconds average instead of 4,5 seconds average with RT App)

Edited July 2Jul 2 by kiek

26 minutes ago, kiek said:

I am also at EHAM now and I see no problems.

There has always been a small adjustment effect after take-off, because PSXT has to align the aircraft with the airborne RT data. During the take-off roll, PSXT overrides the RT data to achieve the required speeds. But that has been the case from the beginning.

EDIT: I recommend to use RT Direct, that gives slightly better results (data every 3 seconds average instead of 4,5 seconds average with RT App)

Yep, no problems at all at EHAM. A few hours ago I tested at KSEA and saw the slow-motion effect over there. As you said, this must be bad data from RT.

Hi Nico,

I continued testing, this time at KSFO and KSAN. In SFO the departure traffic never took off, there was no rotation, and it was running into the city. At KSAN they took off, and immediately the slow-motion appeared.

If you need more testing, I'll gladly help to find the issue.

Cheers!
Jaime
Monterrey, Mexico

I know the issue. I mean the algoritmes of PSXT produce good results at most airports and bad results at some other airports. The only difference is the input data from RT...

I have to find heuristics to overcome this bad data.

On 7/3/2026 at 1:22 AM, jcuellar said:

In SFO the departure traffic never took off, there was no rotation, and it was running into the city.

I'm testing at KSFO now with a 14 hours time shift, but everything looks normal.

Could you specify exactly in utc time if and when you see such things? Then I can check it.

On 7/5/2026 at 9:07 AM, kiek said:

I'm testing at KSFO now with a 14 hours time shift, but everything looks normal.

Could you specify exactly in utc time if and when you see such things? Then I can check it.

Hi Nico,

I think data is normalizing now. Last night I spotted LSZH for a couple of hours without issues.

Hi Nico,

Unfortunately the slow motion effect is back, I'm spotting right now (0547z) at LSZH. All departures have this behavior.

If I can help with some testing, I'll gladly do ti.

Jaime

11 hours ago, jcuellar said:

Hi Nico,

Unfortunately the slow motion effect is back, I'm spotting right now (0547z) at LSZH. All departures have this behavior.

If I can help with some testing, I'll gladly do ti.

Jaime

I've checked LSZH, only a few aicrat slow down, which is caused by bad RT data. I cannot do much about it.