Too warm temps +15C at high altitude AS2012 solution

[pvarn 0]

For those struggling with suddenly unrealistic +15C temperatures at high altitude, I've been testing this problem for months and have something for others to try.

 

I've not seen this problem except while using DWC, so if this is you, try setting the AS: WX Options: Dynamic Rate of Change slider in Active Sky to zero. This slider also moves the same feature in FSX: Display->Weather->"Rate at which weather changes over time." What this slider does is allow FS to internally morph whatever weather is loaded into it (whether it's the built-in weather themes, weather you created as custom yourself, weather saved with a flight, or downloaded weather.) The further to the right the slider, the faster the changes occur, so those using low setting may appear to have random results. I used "20" which is the lowest setting in AS which results in the lowest setting above zero in FS so my morphing was happening between 40 minutes to an hour into the flight. My theory is this morphing can create the single layer of +15C ground temperature used as "Clear and Calm" which sets the entire FS envirnment to one unrealistic temperature at all altitudes for a random period of time.

This may affect ASE also.

 

See if this helps and let us know. Thanks.

-Pv-

[Paul Deemer 13]

Are you using FSINN? If so that could be your problem. Right now at FL380 with DWC its -17c outside. Don't forget its summer time and with some of these record breaking heat days its not uncommon to be taking off from an airport where its 40c which is 104F. When I am in this kinda heat I dont hit the - side of the scale until I hit the higher end of FL200s. As for Dynamic rate of change the recommended setting is 0.

[cappinsuruje2 1]

MY dynamic rate of change slider is set to zero and I still get high temps at altitude. The trick for me is to start FSX then start AS2012.

 

Gideon Warde

[pvarn 0]

You'll see this issue discussed elseware in topics close due to age. Others who fly airliners at the typical 30K-40K ft have noted this problem in advanced aircraft which are sensitive to excessive heating and shut down the engines at cruise. The SR71 I fly will lose an engine when the engine intake exceeds 450C as it does when the +15C hits.

 

Although I'm using FSINN, it's weather feature is tuned off. I typically fly between 60K to 85K ft where the real world temps are between -50 to -80C. To get +15 at 80K ft isn't season related. It's simply impossible in the real world. I have been researching why AS generates this temperature since the Fall and have narrowed it down to this setting. In my opinion, this slider should be removed or disabled from AS when using DWC since it has no positive effect. In "Normal" mode it can have a SLIGHTLY positive effect in helping to prevent jarring and sudden changes in weather since FS itself will gradually morph the weather between what it has and the new load. However, this is at the cost of creating unrealistic weather at times. In Normal mode, this setting has not caused any +15C jumps at high altitude. Those who have FSUIPC and use the smooth winds feature, can get rid of the wind direction jumps without using the Dynamic Rate of change in Normal mode.

 

Turns out it isn't AS generating the anomaly, but FS, I believe, but this setting triggers it.

 

-Pv-

[ailchim 216]

Please, please forget FSInn, I beg you. I've never ever used that product and yet I've had repeated problems with excessive TAT! It must therefore be a complete red herring.

 

I've been flying the PMDG 737 NGX pretty regularly for a couple of months now under AS2012. I have DWC on and [coincidentally] the Rate of Change slider set to zero. Whether it's AS2012 or just a fluke of hitting on these settings, I'm not having a big problem with TAT, whereas I was plagued with it a while back while the PMDG MD-11 was the thing to fly.

 

I do notice that there is still something going on: the engines do occasionally throttle right back and when I look at TAT it's at some number well above zero [>+15 degrees at FL300?] but it seems to rectify itself within seconds, so you don't fall out of the sky with zero thrust!

[pvarn 0]

Even with the slider at zero, I still had another +15C episode at cruise, so now back to testing an older theory that it's related to download interval.

 

In airliners, the default interval of 10 or more works fine (or should.) In the case of the SR71 which covers 33+ miles a minute, it doesn't take long to fly past the FSX in-air weather radius of 30 miles which means an external weather program must update the weather in FS frequently to avoid FS generating Clear and Calm if there isn't replacement weather available for the next geographic area. Damian informs me DWC updates the weather every 300 ms from available download weather cache.

 

When I have used 6 minute download interval (which means AS is gatherin new weather reports every ~200 miles of SR-71 cruise distance) I have not had any what I call temperature "flips" (ground temperature at cruise altitude.) These "Flips" can be transitory (1 second or less) or last for several minutes. They can appear randomly (it's possible to fly the same flight plan many times and see the flip only once. However, there are geographic areas of the world, where if I fly it often enough, I'll eventually get a flip and when I fly anywhere else, I never get a flip. Why? Who knows. Some observations:

 

1) I always use a flight plan. Is there a negative influence on the downloaded weather sent to FS based on the plan (misinterpretation of the plan so the required weather for an area isn't available to FS? Perhaps there are weather holes created by the interpretation of the plan where a slight deveation in flight causes a miss?

 

2) Is there an interaction problem in FS where something prevents one or more of those 300ms updates from "taking" and AS doesn't know about it?

 

3) I also use FSUIPC. I see in the V4.827 notes there are recent fixes where AS and FSUIPC communication has been improved. However, supposedly AS doesn't use FSUIPC to transfer the weather, but uses simconnect.

 

4) I do used FSINN because I fly on the VatSim network. At this point, we "Vat" flyers use Squawkbox of FSINN and the later is the most stable and useful of the two. I've pretty much ruled that out as a contributor.

 

5) Because these flips are tied to geographic areas, I suspect there may be data in those areas either FS itself, or the combo of AS DWC is a trigger.

 

6) FS's won internal "Jeppeson" weather simulator/data never triggers the Flip.

 

7) AS's "Normal" mode (most like FS's Jeppeson) never triggers the flip.

 

Note: DWC is focused on writing "global" weather, while "Normal/Jeppeson" style simulation actually write individual stations.

 

FS's global behaves in two ways:

 

a) When written on the ground, the created environment is truly global. That is, with no more weather writes, the player can fly the entire world with no change in environment.

 

B) When writing global while airborne, FS creates that weather within a 60 mile circle of the current position of the aircraft. Fly outside that circle, and if there is no geographic weather for that specific area, FS will revert to it's default clear and calm (which if the created weather you were flying in was quite different, the impact on the aircraft can be quite jarring.)

 

8) When FS internally reverts to clear and calm, one layer is created with +15C on the ground (as observed in Downson's Weatherset program.) This is also what I see when I get the flip in AS flight (where normally AS generates multiple layers.) This suggests, FS has detected no current weather for the area, and substituted C&C until it gets new valid weather data for the area (whenever this occurs.)

9) There are only 3 areas of the world where I get the flips. Season is not a factor:

a) US mountain area timezone (mountain states: Idaho, Utah, Colorado, Arizona, New Mexico, Nevada)

b Canada New Foundland area

c) South Eastern England

 

This is all I know for now. Other player experiences are welcome.

 

-Pv-

[ailchim 216]

Thanks for the comprehensive post.

 

Let's hope the HiFi people are reading this forum. I was hoping those that had submitted tickets on this issue would give us feedback on the response they got but i haven't seen any.

[pvarn 0]

HiFi has been very aggressive on this issue. Unfortunately, the few people affected (those that know it at least) the complex combinations of environment data and program settings have made this very hard to nail down. This is why I have started a new thread after the old ones died in hope of getting others who have seen the problem to contribute, compare observations in hope of gaining more insight. The closer to the ground and slower, the less likely to see the affect of a brief disturbance. 99.9% of the aircraft out there have been made so forgiving (especially the engines) it might look more like a weather burp to most people where the engines surge or lose power momentarily. Because the temp change at high altitude and speed is so drastic ( change of 50-100C and back again) AND the limited part of the world affected, many pilots will not see it at all.

-Pv-

[ailchim 216]

When you say "very aggressive", what do you mean?

 

Very aggressively trying to find and solve the problem? Or something else?

[pvarn 0]

Very aggressively trying to find and solve the problem.

 

On Sunday I had the flip using 6 minute updates on a flight where I had not had it before flying from Guam to Honolulu. I then flew the same flight again using "Normal" mode and although the flight was not "normal" (wide, non-smoothed temp variations) I did not get any flips (which is what I expected. I then flew the same route Monday with the new SP1 feature "Local Station Writes with DWC" and had a very nice flight. All temps were within expected ranges and no flips.

-Pv-

[ailchim 216]

Excellent.

 

I don't have "Local Station Writes with DWC" ticked but since a) I'm not having much trouble with temperatures at the moment [although I have had in the past] and B) I can't stand cloud cover flicking in and out, which is apparently a side effect of this feature, I'll leave it un-ticked.

 

It's interesting I'm flying over densely packed Europe whereas your flight was over water. I wonder if the big blank area of sea with no weather stations is a factor?

[pvarn 0]

I get these over the Western US and Eastern England which are of average density or more. I'm hoping more people who have experienced this problem will share their observations. Every setting in AS has its trade-offs which is why they're there.

-Pv-