Huge airspeed loss passing from day to dusk! Help pls.

[Berthin Hudon 0]

Hi everybody,

First, sorry for my English...will try to explain my prob. the best I can.

I have been simming for about 20 years. I switched to P3d v4 mid-july and all was working well, great flights with PMDG 737-800 and 747-400, MJQ Dash8, FsLabs A320. I usualy fly in the afternoon, ending my flights at CYUL (Montréal, Qc) between 5 and 6 pm. 2 to 4 hrs flights. As I said, all was OK till the beginning of November. Then. I had a flight (KSFO/CYUL) with FsLab. A320
when  suddendly, at cruise altitude, airspeed dropped in 1 second to 40-50 kts, of course, autopilot disc. and plane went in spiral dive I could not recover from.
First thing I thought was a scenery or plane prob.. I repeated the same flight plan some days later with another plane (PMDG 744). Same thing happened but 40-50 nm before. So it was not the plane.
Did another flight KMIA-CYUL with PMDG 738, same thing. So was not a scenery/plane  prob.
The day after, I repeated the second flight but with take off in the morning as I had to leave house in mid afternoon and all went good and landed at CYUL without prob.
Scratching my head I thought that with all those incidents were arriving at the end of the PM, were they related to time of day???
So, I repeated the KMIA-CYUL flight this morning here but changing sim time to 4h45pm local at MIA. The flight lasted only 1h14...........and the prob. appeared.
So, could it be when the sim change from "day" to "dusk" ????  It would explain why was OK for me in august, sept. oct. and has only begun in november after switchong back to Normal EST. Before that, dusk was after 6 pm here.
Have some of you had this prob. and how to solve it?
Thanks

Berthin

Win7 64bits,   I7-3930K @  3.20MHz,  16G RAM,  2 x  GTX560 SLI, FSUIPS5 reg., ACTIVE SKY for P3d v4

[Nighthwk 566]

This has been known to happen with Active Sky changing the winds abruptly as it receives new data for winds aloft. Try disabling Active Sky and see if that solves the problem.

[Bob Scott 7,720]

Could be icing.  ESP platforms have always had extremely unrealistic severe effects when pitot icing occurs.  You might try disabling or limiting the max level of icing in AS/P3D.

Regards

[thetford569 104]

This is curious because I have had the exact same issue as you are reporting but with a completely different aircraft and flight plan.  I've been using the Carenado Citation CJ2 and it will suddenly spin out of control while climbing or at cruise.  I have not thought about time of day and I only fly using real weather.  I would be curious to see if this happens to you while flying to another airport at the same time of day.  I am at a loss as to the cause of it on my machine but now I will do some more testing as well.  I thought it was Active Sky winds as well until yesterday when I spun out of control with a light tailwind around 10/15,000 ft.

Brandon

[Berthin Hudon 0]

Thanks Milton, Bob and Brandon.  This week, will test same flights without AS and  if it not conclusive, will try flights at day/dusk change in differents parts of the world.

Will give feedback.

 

Berthin

[scottb613 1,188]

Hi Folks,

RE: AS4

Been trying to fly approaches into Block Island KBID all day - massive (plane falling out of the sky) wind shear on approach (@ transition to feet dry) to 28... Airspeed goes from 80 to 0 in the blink of an eye along with the freefall... Never had this problem before... Odd...

Regards,
Scott

 

[Nighthwk 566]

34 minutes ago, scottb613 said:

Hi Folks,

RE: AS4

Been trying to fly approaches into Block Island KBID all day - massive (plane falling out of the sky) wind shear on approach (@ transition to feet dry) to 28... Airspeed goes from 80 to 0 in the blink of an eye along with the freefall... Never had this problem before... Odd...

Regards,
Scott

 

You can turn down the windhsear intensity settings in AS.

[scottb613 1,188]

Hi John,

Yep - familiar - just stating it's odd as I use it all the time and this weekend is the first time I've ever seen it...

Regards,

Scott

[Nighthwk 566]

1 minute ago, scottb613 said:

Hi John,

Yep - familiar - just stating it's odd as I use it all the time and this weekend is the first time I've ever seen it...

Regards,

Scott

Maybe it's to do with real world weather somehow.

[scottb613 1,188]

Hi John,

Regards,
Scott

 

[thetford569 104]

I've used Active Sky for P3D with every flight.  I wonder if this is something to do with their latest update because recently I did update the program to the latest version and am now having this issue.  Will do some testing myself to see if it's AS causing the problem.

Brandon

[BrianW 124]

6 hours ago, scottb613 said:

Hi Folks,

RE: AS4

Been trying to fly approaches into Block Island KBID all day - massive (plane falling out of the sky) wind shear on approach (@ transition to feet dry) to 28... Airspeed goes from 80 to 0 in the blink of an eye along with the freefall... Never had this problem before... Odd...

Regards,
Scott

 

It’s interesting you bring this up. I had the same issue with windshear at KBID a few weeks ago and the METARs today look very similar.  There were gusts with winds between 300-320 when I experienced it too.  I’m not sure what was causing the windshear, but the winds were pretty consistent at all altitudes and at nearby airports with no convective activity. So far it’s the only airport I’ve seen this happen.

[thetford569 104]

OK!  Here are the results of my testing with the sudden loss of airspeed and subsequent stall and unrecoverable spin....

I tried the same flight KLAX to KDFW departing at the same time of 16:00 Local (00:00 Zulu).  This time is about 13 minutes before dusk.  I tried it both with Active Sky running and without.  Each time when the clock in my aircraft gets to 00:13 Zulu (and some seconds after) the aircraft loses airspeed and enters an uncontrollable spin.  There is no wind shear or sudden wind change.  I tried using anti-icing and it didn't change anything.  The only thing that kept me from entering this spin was to fly at 10:00 local during the day time where there was no transition between day and dusk.  This sucks because that is my personal favorite time to fly.  Something is wrong here and I can't believe others are not having this issue.  I will take this to the Lockheed P3D forums because to me this does not seem like a real weather (Active Sky) problem but a P3D bug.  I would appreciate maybe if some more of you could test this out and see what you come up with.

For more details on my flight and testing purposes I was climbing using the auto-pilot to FL350.  Didn't matter the altitude I was at the time it was just when the clock went to 00:13 Zulu everything happened.  I have not tried a low level flight to see if the clock causes the same thing.  I may try that next since someone above reported the issue on approach to BID.

Brandon

[scottb613 1,188]

Hi Brandon,

Since Brian saw something very similar at the same spot - I reported what I described to HiFi this morning - via support tix - no response yet - I'll post here if they find something...

Regards,
Scott

 

[thetford569 104]

I just tried a default aircraft in 2 different locations not using any add-on airports. When the day to dusk transition happens the aircraft loses airspeed, stalls, and then spins. I also was using no weather add-ons. I can replicate this problem. The last time I was in the default Mooney at 3,000 ft. and it happened. This is a bug. Flying between day and dusk is not working.  I have reported all of this at LM forums...

Brandon