JS4100 Icing

[Guest pjpilot]

I enjoy the JS4100, which I am running with Active Sky Advanced. However, I find it is very sensitive to icing, even in conditions that should not produce icing, such as flying well above or clear of any cloud cover. It seems to be necessary to engage all deicing systems, including manually engaging the airframe autocycle on a very frequent and repetetive basis in order to prevent an icing warning on the Cap and/or engines shutting down in flight. Is this normal for the real world JS4100? I don't see much posted on this topic, so maybe my simulation is not running properly.Paul Lowry

[Guest Jimmatc]

I agree, icing accrual happens far too often. It seems to me that if the temperature is between +5

[Zachiii 0]

I enjoy the JS4100, which I am running with Active Sky Advanced. However, I find it is very sensitive to icing, even in conditions that should not produce icing, such as flying well above or clear of any cloud cover. It seems to be necessary to engage all deicing systems, including manually engaging the airframe autocycle on a very frequent and repetetive basis in order to prevent an icing warning on the Cap and/or engines shutting down in flight. Is this normal for the real world JS4100? I don't see much posted on this topic, so maybe my simulation is not running properly.Paul Lowry

It is too sensative.I fly with all deice ON.PMDG needs to address this issue.zach bogue

[Guest realatp]

agreed. Seem like no matter what your getting icing everywhere in the clouds even if your at FL25 goin' through Cirrus (ice crystals).

[vivek 0]

i have seen icing on hot summer evenings when there should have been none,vivek

[emvaos 13]

Gents,Precipitation information is obtained directly from FSX. Let me repeat that : Precipitation information is obtained directly from FSX !You are right that FSX will often report precipitation above cloud layers. From that point, rate of accumulation/removal/dissipation is modelled by us using real physics. The rate model is based on TAT not SAT (static temperature is entirely irrelevant on a moving object...). Unfortunately apart from modulating icing rate based on total temperature and real world physics we are in no position to cross-check whether said precipitation information is correct. There is no mechanism or SDK function or direct/indirect manner to do this. Incidentally this is why all WX radar information in FSX is a joke in terms of realism. Developers face the exact same issue. Accordingly there is nothing to patch other than FSX itself in this respect. Begin a petition and I'll gladly join in this area.A word of caution : FSX does feature an ice weight accumulation and prop icing model. After 15 minutes in severe icing the aircraft performance will degrade considerably even if precipitation conditions should not be reported in the first place (visible moisture etc). If total temperature is within range of our rate model then you have to use deice otherwise you 'll find out that in high ISA, high altitude you will experience performance difficulties.Vangelis

[Buzz313th 0]

Gents,Precipitation information is obtained directly from FSX. Let me repeat that : Precipitation information is obtained directly from FSX !You are right that FSX will often report precipitation above cloud layers. From that point, rate of accumulation/removal/dissipation is modelled by us using real physics. The rate model is based on TAT not SAT (static temperature is entirely irrelevant on a moving object...). Unfortunately apart from modulating icing rate based on total temperature and real world physics we are in no position to cross-check whether said precipitation information is correct. There is no mechanism or SDK function or direct/indirect manner to do this. Incidentally this is why all WX radar information in FSX is a joke in terms of realism. Developers face the exact same issue. Accordingly there is nothing to patch other than FSX itself in this respect. Begin a petition and I'll gladly join in this area.A word of caution : FSX does feature an ice weight accumulation and prop icing model. After 15 minutes in severe icing the aircraft performance will degrade considerably even if precipitation conditions should not be reported in the first place (visible moisture etc). If total temperature is within range of our rate model then you have to use deice otherwise you 'll find out that in high ISA, high altitude you will experience performance difficulties.Vangelis

The built in FSX icing does not hit the model hard enough... I wish you guys would sync the FSX ice acumulation with your own VISUAL ICING MODEL so that VISUAL ICING ACTUALLY AFFECTS MODEL PERFORMANCE.JB

[MELKOR 5]

Developers face the exact same issue. Accordingly there is nothing to patch other than FSX itself in this respect. Begin a petition and I'll gladly join in this area.

Unfortunately, ACES is toast... there won't be any FSX patches forthcoming.However... where there's a will, there's a way.I've heard that the weather code is isolated to a single .DLL. If that is true, a replacement could be written from the ground up to fix the huge number of issues with the existing code.I have concrete ideas on how this could be accomplished. But, alas, I simply don't have the time to take this on (there is a very substantial amount of work involved!)If there are any experienced developers out there that have the time and the will, let me know, and I'll share my ideas.

[EvgenyK 0]

A word of caution : FSX does feature an ice weight accumulation and prop icing model. After 15 minutes in severe icing the aircraft performance will degrade considerably even if precipitation conditions should not be reported in the first place (visible moisture etc). If total temperature is within range of our rate model then you have to use deice otherwise you 'll find out that in high ISA, high altitude you will experience performance difficulties.

Just wonder - can I fall because of it?Also would like to mention for other posters that just today I've been reading great post about icing from real airline pilot (sorry, post is in Russian), and one of things I've learned from it - that it might happen in places where you really don't expect anything like this, he wrote that he experienced it in Dubai.

[Guest pjpilot]

Thanks to all who took the time to respond to my icing post. If this were exclusively an FSX problem, then I would have thought other aircraft would have similar icing issues. But this is not the case. I have enjoyed PMDG's 737NG (for FS9) and the MD11 for FSX, as well as other add-on aircraft, none of which have had similar icing issues. I find that if you do not deploy full deicing shortly after take off in almost any conditions, then the engines will simply quit in the climb (I have yet to get them restarted, so for me the flight ends). I also find that while the CAP shows an ice warning, neither the amber, nor the red, warning lights and audio signal engage before the engines shut down, so there is no opportunity to avoid engine shut down. This is a bit of a problem because I am not normally monitoring the CAP on a continuous basis, and I tend to rely on the warnings. Perhaps nothing can be done about this. Fortunately, you can enjoy this otherwise excellent aircraft by ensuring that deicing is fully and continuously deployed in most conditions, whether or not you would normally expect icing in such conditions. Not quite realistic on this particular point, but still a good simulation overall.Paul Lowry

[Buzz313th 0]

Thanks to all who took the time to respond to my icing post. If this were exclusively an FSX problem, then I would have thought other aircraft would have similar icing issues. But this is not the case. I have enjoyed PMDG's 737NG (for FS9) and the MD11 for FSX, as well as other add-on aircraft, none of which have had similar icing issues. I find that if you do not deploy full deicing shortly after take off in almost any conditions, then the engines will simply quit in the climb (I have yet to get them restarted, so for me the flight ends). I also find that while the CAP shows an ice warning, neither the amber, nor the red, warning lights and audio signal engage before the engines shut down, so there is no opportunity to avoid engine shut down. This is a bit of a problem because I am not normally monitoring the CAP on a continuous basis, and I tend to rely on the warnings. Perhaps nothing can be done about this. Fortunately, you can enjoy this otherwise excellent aircraft by ensuring that deicing is fully and continuously deployed in most conditions, whether or not you would normally expect icing in such conditions. Not quite realistic on this particular point, but still a good simulation overall.Paul Lowry

Paul, are you actually getting the engines to shut down because of Naucelle Icing? Thats good news, since the release version of the J41 (before SP1) was unaffected by ice buildup and the only consequence was a visual layer of ice.JB

[downscc 1,327]

Not quite realistic on this particular point

My ice protection is always turned on below 10C flying real world (Cessna C-414), except the boots. Those wait for visible ice.

[curt1 79]

Thanks to all who took the time to respond to my icing post. If this were exclusively an FSX problem, then I would have thought other aircraft would have similar icing issues. But this is not the case. I have enjoyed PMDG's 737NG (for FS9) and the MD11 for FSX, as well as other add-on aircraft, none of which have had similar icing issues. I find that if you do not deploy full deicing shortly after take off in almost any conditions, then the engines will simply quit in the climb (I have yet to get them restarted, so for me the flight ends). I also find that while the CAP shows an ice warning, neither the amber, nor the red, warning lights and audio signal engage before the engines shut down, so there is no opportunity to avoid engine shut down. This is a bit of a problem because I am not normally monitoring the CAP on a continuous basis, and I tend to rely on the warnings. Perhaps nothing can be done about this. Fortunately, you can enjoy this otherwise excellent aircraft by ensuring that deicing is fully and continuously deployed in most conditions, whether or not you would normally expect icing in such conditions. Not quite realistic on this particular point, but still a good simulation overall.Paul Lowry

Our experiences totally differ on this. I always get an amber warning, along with a chime alerting me to icing conditions. If I'm staying aware, I'll get the anti-ice on beforehand; if not the warning makes me take action. I've NEVER had the engines shut down in flight, so I wonder what the difference is in our setups? I do use ASA, maybe I have a setting in that program that limits icing, but I don't think so. I believe you're the first to report engine shutdowns from icing, so you may want to examine what other addons you're running. Just a thought, I hope you find the cause.Curt Branch

[Guest pjpilot]

Our experiences totally differ on this. I always get an amber warning, along with a chime alerting me to icing conditions. If I'm staying aware, I'll get the anti-ice on beforehand; if not the warning makes me take action. I've NEVER had the engines shut down in flight, so I wonder what the difference is in our setups? I do use ASA, maybe I have a setting in that program that limits icing, but I don't think so. I believe you're the first to report engine shutdowns from icing, so you may want to examine what other addons you're running. Just a thought, I hope you find the cause.Curt Branch

ASA does have several settings re icing. In "Options - Clouds", the default for "Maximum Cloud Icing" is 100%. After reading your post, I have reduced that to 50%, and will see if that makes any difference when I have a chance to run a test.Paul Lowry

Paul, are you actually getting the engines to shut down because of Naucelle Icing? Thats good news, since the release version of the J41 (before SP1) was unaffected by ice buildup and the only consequence was a visual layer of ice.JB

Yes, I think it is nacelle or engine icing, as there appears to be some visual effects confirming that. Also, I have SP1 installed.Paul Lowry

Our experiences totally differ on this. I always get an amber warning, along with a chime alerting me to icing conditions. If I'm staying aware, I'll get the anti-ice on beforehand; if not the warning makes me take action. I've NEVER had the engines shut down in flight, so I wonder what the difference is in our setups? I do use ASA, maybe I have a setting in that program that limits icing, but I don't think so. I believe you're the first to report engine shutdowns from icing, so you may want to examine what other addons you're running. Just a thought, I hope you find the cause.Curt Branch

P.S. The only add-ons I am running are ASA and the TrackIR 5 software.Paul Lowry

[michal 44]

whether or not you would normally expect icing in such conditions. Not quite realistic on this particular point, but still a good simulation overall.

Paul,This is a big problem with icing and realism within confines of FS.I am afraid that if someone wanted to deliver realism people would complain that there is no ice at all. I still recall what editor of Flying McClellan once wrote about real world icing - it is extremely rare even if conditions seem to indicate that icing should be there. He has accumulated over 4000 hrs in Beech Baron flying hard IFR in North-Eastern US in low altitudes (where Baron goes) and had to use his boots only once or twice. You would need a very sophisticated weather engine in FS to give you this realism - but then again, folks would complain 'where is the ice', I am in visible moisture, it is -2 C and I see no ice. A good way to solve this problem would be ad some sort of probability setting - this way a user could control how much icing he/she wants.