sudden wind change during landing

[snoopy_belgium 0]

I'm have a problem with wind changes during landing in P3D 4.1 with AS4.

Yesterday I had  a flight with a Cherokee to Antwerp (EBAW). The metar for this airport in AS4 showed that the wind was 238/8 knots. During the approach for runway 29 the wind was correct, but when I was ready for touchdown the the wind changed suddenly to 30/33 knots for the last 10-20 feets. So the airplane was pushed in the sky again because of the strong winds and it turned diagonal towards the runway.

I have performed a missed approach and when I was climbing the wind changed again to normal. I made a second attempt and during this approach the same behavior was observed. On the AS4 map I saw that the metar of the weather station was correct, but when I clicked on the aircraft symbol the displayed wind was the strong wind and there was also a red text about wind shear. 

So it seems that AS4 is causing some wind shear around the aircraft and this wind shear is following the aircraft during some time around the airport. This is not very accurate. Wind shear is happening during a very short time period and it should be different every-time it happens.   

I have seen this behavior already several times in AS4.  Yesterday evening there were some thunder storms in the area so wind shear was a possibility. But when I fly to Tenerife South (GCTS) with an airliner I see this behavior during every landing on runway 08, also in perfect weather conditions.  With an airliner there is no time anymore to correct the flight when the wind changes suddenly the last 10 feet because the airplane looses the its lift and it will come down very hard.

Do other users have this same experience with AS4? What can we do to prevent this behavior?  Is there a way to have some realistic wind shear in AS4?

Best regards,

Snoopy

Belgium

[BuddyDog 36]

I believe in the settings for ASP4, you can tick a checkbox "Prevent downloads during approach", which should eliminate that problem.  You can also limit maximum wind speeds on the ground in the settings.

[snoopy_belgium 0]

Thanks for your reply.

I was also thinking about this checkbox, but I think this is a different problem. During the final approach there is no weather update. Otherwise the problem would not be happening each time a land on the same runway.

I believe there a two possibilities:

- AS4 adds a thin layer above the runway on particular airports  in which the wind comes from a completely opposite direction and the strength is much higher. So the wind layer doesn't follow the metar of the airport. Both airports have non default scenery installed, so maybe the airport elevation has some influence on this.

- or, and since what I saw yesterday I have more believe in this: during landing the aircraft comes in a kind of Wind Shear modus. When this modus is triggered the wind changes completely to other values until the conditions are not met anymore. But this is not very realistic because the strong wind stays in that way in the vicinity of the airport.

Best regards,

Snoopy

Belgium

 

 

[kterz 49]

Hi, not sure the exact time you've been there. This is what I get for yesterday:

 

at 1400z:  EBAW 181420Z 27015KT 250V310 9999 BKN027 07/02 Q1002 TEMPO 25025G35KT

at 1500z: EBAW 181520Z 28012KT 9999 SCT032 SCT045 07/02 Q1002 TEMPO 25015G25KT

at 1600z: EBAW 181620Z 27010KT 9999 SCT032 SCT045 07/01 Q1002 TEMPO 25015G25KT

at 1700z: EBAW 181720Z 26006KT 9999 SCT032 SCT045 07/02 Q1002 TEMPO 30015G25KT 3500 SHRA

at 1800z: EBAW 181820Z 21006KT 9999 SCT032 SCT045 06/02 Q1002 TEMPO 30015G25KT 3500 SHRA

at 1900z: EBAW 181920Z 23008KT 9999 -TSRA SCT020CB SCT045 06/03 Q1002 TEMPO 30015G25KT 3500 TSRA

 

while the TAF for the following hours was:

EBAW 181711Z 1818/1903 25010KT 9999 SCT025 TEMPO 1818/1903 30015G25KT 3500 SHRAGS SCT008 BKN012CB

Please refer to the exact metar when reporting an issue or claiming that something is not realistic, so that we can be on the same page

[snoopy_belgium 0]

The Metar was the last one:

at 1900z: EBAW 181920Z 23008KT 9999 -TSRA SCT020CB SCT045 06/03 Q1002 TEMPO 30015G25KT 3500 TSRA

So I had some wind (8 knots) coming from my left side during ILS approach for runway 29. But then suddenly when I was nearly at touchdown the wind changed to 30/33 knots. It remained so when I was flying over the runway and was trying to land which was impossible of course. 

When I left the airport the wind changed again to the normal values in the metar. During my second try 15-20 minutes later the same happened with the same values for the wind.

I can reproduce this behavior at GCTS for runway 08 so I can make some screenshots and record the precise data at this airport.

Best regards,

Snoopy

Belgium

[fppilot 4,352]

Hummm. Can you turn off the weather engine and see what happens?

[JesC 88]

27 minutes ago, snoopy_belgium said:

The Metar was the last one:

at 1900z: EBAW 181920Z 23008KT 9999 -TSRA SCT020CB SCT045 06/03 Q1002 TEMPO 30015G25KT 3500 TSRA

So I had some wind (8 knots) coming from my left side during ILS approach for runway 29. But then suddenly when I was nearly at touchdown the wind changed to 30/33 knots. It remained so when I was flying over the runway and was trying to land which was impossible of course.

I may be confused (not unusual). But, isn't that behavior consistent what would be expected from that METAR; "TEMPO 30015G25KT"?

Jesse

[pasterke 4]

there was a heavy storm over Belgium yesterday with heavy gusts
air traffic has even been shut down for a while

as real as it gets

[snoopy_belgium 0]

Yes, there was a storm yesterday, but it was in the morning between 7 and 10 UTC. After that the wind went down and in the afternoon it cleared up. Only in the evening there were some showers.

When I was flying there were inderdeed some gusts now and then, but mostly the flight was very stable because the wind at EBAW was 230/8knots. So Active Sky really made the flight very realistic!

But during landing it was not very realistic.

But I will reproduce it at GCTS in weather conditions that are not stormy at all and I come back with my results.

 

Thanks for the replies,

Snoopy

Belgium

[skelsey 765]

26 minutes ago, snoopy_belgium said:

When I was flying there were inderdeed some gusts now and then, but mostly the flight was very stable because the wind at EBAW was 230/8knots. So Active Sky really made the flight very realistic!

But during landing it was not very realistic.

But the METAR for the time you were landing did not just state 230/8: it also stated that there were thunderstorms and gusts of 25 kt (bearing in mind that the gust in the METAR is simply what was recorded in the 10 minute period prior to the METAR and so there's no reason actual gusts couldn't be more). This is what AS was replicating.

[DaveCT2003 1,820]

I'd like to add that wind is never, ever constant, and landing an aircraft with changing winds is a very normal and routine occurrence.  This happens not only due to wind variability (nature and due to natural and man made structures) but also compounded by the aircraft changing altitude on approach. The only constant is that it will be variable - always!

I'd roll with it, and get used to compensating for it. 

Best wishes!

 

[snoopy_belgium 0]

I did some investigation about this subject.

First GCTS:I now realised that I always had this behavior in P3D3 and AS16, and since I'm not using these two anymore I cannot go back to reproduce it. And in P3D4 and AS4 it works fine with the weather conditions of this evening. So good news!

But back to EBAW. Indeed, gusts can be higher than the metar says, but gusts are gusts and should not be constant.

So I did the following test now:

- I parked the plane on Runway 29 of EBAW. AS4 is set to the current time 19/01 at 2041UTC, so no gusts at all. I see the following in AS4:

When I move the cursor to the aircraft on the map I get following info:

So everything OK now!

But then I switch to historical time in AS4 and go back to yesterday evening 18/01 19UTC. We get the following conditions:

and for the airplane:

So 336/31 knots and a wind shear alert. In P3D I see the following information:

The strong wind is constantly blowing from a constant direction with the same strength. So no gusts at all, just constant wind. When I take off the wind starts to change slowly when I leave the airport area and becomes normal again.

But now comes the best part!!!!

I switch AS4 back to the current weather. So no gusts anymore and indeed the clouds and rain get removed out of the sim because the weather changes to the current conditions. But the strong wind and wind shear alert don't disappear at all, both in the sim and on the AS4 map.

So there must be something wrong. Why is the wind shear a constant wind and why doesn't it get cleared when the conditions change?

Best regards,

Snoopy

Belgium

 

[kterz 49]

Hi,

 

unable to reproduce the "change back to live weather and ws warning not going away". In my case, once live weather was downloaded and injected, the winds and warning disappeared (as they should). May be it's a timing issue and since this is easily reproducible, I welcome any fellow simmer/ ActiveSky user to give this a test. If there is an actual bug, then please open up a support ticket so that we can investigate in which configurations this surfaces up.

One other thing that would be really helpful is to enable the "Shear" button on the map. This would show something like this:

 

 

This shows the presence of a microburst around the airport at the time. Please keep in mind that gusts are a different thing compared to wind shear/microbursts. The wind direction in a microburst is centrifugal (and not "steady") from a specific "center" where also the downdraft is maximized. This is the way this phenomenon is described in real life and that's the way we simulated it.

As for your landing issues, I suggest (at least for GA aircraft that don't have an on board radar), that you install XGauge and enable the aural prediciton warnings. Cause in these conditions you are really lucky you didn't actually crash :)

[snoopy_belgium 0]

I did some more research on this issue.

First of all I switched to default scenery to make the comparison easier. By doing that I found out why other users see normal behavior.

For reproducing this issue you have to do the following:

- start AS4 and P3D and park your plane at R29 of EBAW

- change the date and time in AS4 to 18/01 19UTC -> the wind is now what you expect from the METAR

- enter slew mode and move your plane forward past the white line of R29 (you can also push the thrust lever to get there) -> I have now a wind of 334/31 knots!

- switch AS to live weather mode again -> the strong wind remains until AS4 is closed and started again.

Can anyone reproduce this issue?

Thanks,

Snoopy

Belgium

[snoopy_belgium 0]

My previous testing was done in a configured P3Dv4 with lots of scenery and add ons, so in order to eliminate any influence of these I have performed the same test in a virgin P3Dv4 installation and newly installed AS4, all with default settings.

First step: go to EBAW Runway 29 and set AS4 date to 18/1 19UTC:

Wind is according the metar information, so nothing special here.

Step 2: move the plane some meters further towards the white line:

Now suddenly the wind is blowing 31 knots! When you move the airplane around the airport the wind keeps the same strenght.

Switching AS4 again to current weather doesn't remove this strong wind.

Only when AS4 is closed and started again the strong wind is gone.

Maybe it is a bug??? Word Not Allowed, do I have to open a support ticket for this problem? Do you have another idea about this bug/problem?

Thanks a lot,

Snoopy

Belgium