High Altitude Destructive Turbulence?

[RandallR 444]

I've experienced heavy turbulence from time to time in this sim - occasionally in the FL240 - FL300 zone.  I've usually adjusted my altitude and sometimes got relief.  Today at FL280 in the TBM I hit occasional heavy chop over the Alps while in cruise.  I didn't adjust this time (I was actually on a phone call and figured I'd try a higher level in a few minutes if the turbulence continued).

I was drawn back to the screen when there was a loud tone - the screen was blank.  This was followed shortly by a screen message (paraphrased):

You have taken the aircraft beyond its designed limits - there has been a structural failure and you have crashed.

So much for 1 1/2 hours of flight time... Anyone else ever experience this?

[Flyfaster_MTN002 412]

Have always turned the crash stuff off for this very reason.... also because I may or may not crash often 🙂

[marsman2020 1,310]

I've seen a couple of reports of this on MSFS forums.

I think what is happening is that there are 'cells' in the weather data and when you cross the 'cell' boundaries it creates a very rapid change in weather conditions which over stresses the aircraft.  It also shows as a large instant change in speed/altitude, with a corresponding single turbulent event.  I've seen this on a small scale in my Bonanza a few times and it can be scary.

The transition between weather 'cells' should be feathered over several minutes or seconds where the sim interpolates between the old values and the new values, to avoid an instant change.  Or as a workaround if that is too difficult, the structural damage detection should be automatically toggled off around the 'cell' boundaries to allow things to settle down.

Unless there is some kind of a giant storm, a modern aircraft should not be structurally destroyed by turbulence.

I'd recommend filing a ZenDesk ticket and a bug on the official forum. 

Edited March 12, 2021 by marsman2020

[JRBarrett 3,070]

6 minutes ago, marsman2020 said:

I've seen a couple of reports of this on MSFS forums.

I think what is happening is that there are 'cells' in the weather data and when you cross the 'cell' boundaries it creates a very rapid change in weather conditions which over stresses the aircraft.  It also shows as a large instant change in speed/altitude, with a corresponding single turbulent event.  I've seen this on a small scale in my Bonanza a few times and it can be scary.

The transition between weather 'cells' should be feathered over several minutes or seconds where the sim interpolates between the old values and the new values, to avoid an instant change.  Or as a workaround if that is too difficult, the structural damage detection should be automatically toggled off around the 'cell' boundaries to allow things to settle down.

Unless there is some kind of a giant storm, a modern aircraft should not be structurally destroyed by turbulence.

I'd recommend filing a ZenDesk ticket and a bug on the official forum. 

This happened to me a couple of days ago in the CJ4. I was cruising at FL390 with a 125 knot direct headwind, and the wind direction suddenly and instantaneously shifted about almost 180 degrees, causing a major over speed and pitch up. Fortunately, I had crash/damage detection turned off, and was able to recover. I assume it was a data error in the wind parameters for one weather cell. 

[marsman2020 1,310]

Just now, JRBarrett said:

This happened to me a couple of days ago in the CJ4. I was cruising at FL390 with a 125 knot direct headwind, and the wind direction suddenly and instantaneously shifted about almost 180 degrees, causing a major over speed and pitch up. Fortunately, I had crash/damage detection turned off, and was able to recover. I assume it was a data error in the wind parameters for one weather cell. 

I don't think there is anything that says the cells need to be the same at the boundary, since it's one value being used for the entire cell.  Imagine it as the value at the centroid of that cell.

They need to do some kind of smoothing to prevent this.

[Hyperfocal 186]

Out of curiosity, were you above maneuvering speed?

[RandallR 444]

54 minutes ago, Hyperfocal said:

Out of curiosity, were you above maneuvering speed?

I don't believe I was at that moment.  However, the aircraft went beyond the maneuvering speed boundary (for a few seconds) earlier in the flight.

Since the last update the performance envelope of the TBM930 (and the modified version too) has changed significantly at cruise!  The aircraft is still great to fly for the most part, but the old trusted settings at cruise are now way off.  Before the last update I could set torque right near POH of 96% for high altitude and leave it there for best performance.  During descent I wouldn't have to reduce very much to maintain a high (but safe) rate of speed.

Now I have to reduce to around 60% to keep the tape out of the barber pole at cruise!  I noticed this for the first time yesterday - after level-off she just kept accelerating and I kept pulling back and pulling back.  Today as I began to enter the turbulence she was doing the same thing, though I was prepared for it.  Even then, she caught me for a few seconds a couple of times and crossed the boundary for a second or two.  At the time of the catastrophic failure (at least the last time I had glanced at the speed tape) she was about 10 KTS below the boundary.

[Pilot53 544]

I think its pretty realistic, I was flying the cj4 in the 30's over the Himalayas with a wind speed of over 80kts above maneuvering speed.  I hit severe to extreme turbulence, but that's exactly what I would expect in the real world with winds that high in those mountains.  

[marsman2020 1,310]

15 minutes ago, Pilot53 said:

I think its pretty realistic, I was flying the cj4 in the 30's over the Himalayas with a wind speed of over 80kts above maneuvering speed.  I hit severe to extreme turbulence, but that's exactly what I would expect in the real world with winds that high in those mountains.  

This isn't mountain driven.  It happens over flat terrain, and it is massive instant shifts in wind and barometric pressure.  It's down to how they have implemented weather engine.

[Pilot53 544]

6 minutes ago, marsman2020 said:

This isn't mountain driven.  It happens over flat terrain, and it is massive instant shifts in wind and barometric pressure.  It's down to how they have implemented weather engine.

Maybe thats something else, but the OP mentioned heavy chop over the alps, which I think is pretty realistic depending on the winds. 

[JRBarrett 3,070]

6 hours ago, marsman2020 said:

This isn't mountain driven.  It happens over flat terrain, and it is massive instant shifts in wind and barometric pressure.  It's down to how they have implemented weather engine.

That was the first major wind shift I have seen at high altitude, which I think was a data glitch. I have seen many baro pressure shifts at cruise in the flight levels though. Since the altimeter is set to standard, it manifests as a sudden gain or loss of altitude - typically 100-300 feet. If altitude hold is enabled the aircraft usually works its way back to the selected altitude.... until the next time it happens. Both upper wind and pressure do change with horizontal distance in the real atmosphere, but not so quickly. Definitely needs a better smoothing algorithm. That is one of Active Sky’s strengths.

I do experience actual turbulence at high altitudes too. That is realistic as it can happen to real flights.

[skully 1,045]

Extreme Clear Air Turbulence- Be wary when you see a sudden drop of outside air temp, especially when near the jet stream.

[RandallR 444]

I think they've made a decent effort in modeling turbulence, and I have no issue with working my way around the levels to see if I can get relief.  One time the stall warning even went off.  However, it shouldn't rip my wings off!

Also, I second the suggestion re: having a more gentle transition between BP areas.  I had rather violent changes in altitude in the same region just from changing pressure zones (along with shouts from ATC that I was at the wrong altitude).