Rainmaker Posted July 7, 2018 Posted July 7, 2018 I dunno how accurate this is, but I see roughly the same math in a lot of places so it mist be true right?!? :) https://www.onthesnow.com/news/a/15157/does-elevation-affect-temperature Temp appears to drop pretty fastbat altitude, so I would say that temp is not so mich of an issue as the whether or not there is moisture in the air. Without inowing how simplistic/advanced the atmospheric model is in DCS...it’s anyone’s guess on how the conditions are met.
Rainmaker Posted July 7, 2018 Posted July 7, 2018 A-10C was easy to ice over probes at altitude, so something is in the sim...
Flamin_Squirrel Posted July 7, 2018 Posted July 7, 2018 I dunno how accurate this is, but I see roughly the same math in a lot of places so it mist be true right?!? :) https://www.onthesnow.com/news/a/15157/does-elevation-affect-temperature Temp appears to drop pretty fastbat altitude, so I would say that temp is not so mich of an issue as the whether or not there is moisture in the air. Without inowing how simplistic/advanced the atmospheric model is in DCS...it’s anyone’s guess on how the conditions are met. If you're getting icing indications with inlet temperatures well out of the range that suggests you should be getting them, something isn't right. This could be due to: Icing modelling wrong (could be temperature issue or something else) Inlet temperature modelling wrong Icing detector modelling wrong It isn't necessary to isolate the cause of a bug to know it exists.
Rainmaker Posted July 7, 2018 Posted July 7, 2018 If you're getting icing indications with inlet temperatures well out of the range that suggests you should be getting them, something isn't right. This could be due to: Icing modelling wrong (could be temperature issue or something else) Inlet temperature modelling wrong Icing detector modelling wrong It isn't necessary to isolate the cause of a bug to know it exists. Again, you don’t know the inlet temps other than using the engine inlet temp reading, which some are trying use, which is not useful or accurate in this situation. The only way to know if it’s bugged or not is to know current atmospheric temp/humidity in which you are flying. If someone knows how to get that info then awesome, but I don’t know that anyone can.
Nealius Posted July 8, 2018 Posted July 8, 2018 A-10C CDU page gives current OAT. I know ED said they will be modeling humidity, but it hasn't been implemented yet, has it?
Ahmed Posted July 8, 2018 Posted July 8, 2018 For icing to develop you need a temperature range AND moisture. At the moment the advisory is going off when clear of cloud so the logic is definitely bugged
Flamin_Squirrel Posted July 8, 2018 Posted July 8, 2018 ...the engine inlet temp reading, which some are trying use, which is not useful or accurate in this situation. Why not?
Rainmaker Posted July 8, 2018 Posted July 8, 2018 Why not? As I already explained in previous posts...different sensors, different places.
Rainmaker Posted July 8, 2018 Posted July 8, 2018 If corrective actions are about checking inlet temp indication then the warning IS subject to that. No!
Flamin_Squirrel Posted July 8, 2018 Posted July 8, 2018 As I already explained in previous posts...different sensors, different places. I get that; your earlier post was certainly valuable and has solved part of the puzzle. As far as I can see now though, the question is not whether anti-ice makes the inlet ice caution go away, it's should the inlet ice caution have appeared in the first place. The caution seems to be appearing at inlet temperatures outside of the icing envelope, but is this a bug with the Hornet, or the icing model?
Rainmaker Posted July 8, 2018 Posted July 8, 2018 I get that; your earlier post was certainly valuable and has solved part of the puzzle. As far as I can see now though, the question is not whether anti-ice makes the inlet ice caution go away, it's should the inlet ice caution have appeared in the first place. The caution seems to be appearing at inlet temperatures outside of the icing envelope, but is this a bug with the Hornet, or the icing model? What are you basing the inlet temp on? What are you using to measure that? I’m not arguing for or against it being a bug for the record as it may very well be, I just question what people are using as a benchmark to say it is a bug.
chief Posted July 8, 2018 Posted July 8, 2018 If someone is getting the ice indication at 20 degrees at 8000 feet in the Nevada map with no clouds or moisture (Nevada is already drier than a popcorn fart), then it's definitely a bug. You just aren't going to be in icing conditions with those atmospheric conditions.
chief Posted July 8, 2018 Posted July 8, 2018 For icing to develop you need a temperature range AND moisture. At the moment the advisory is going off when clear of cloud so the logic is definitely bugged Kinda true. You can get icing on clear skies if the humidity is high. Rare but can happen.
Eldur Posted July 8, 2018 Posted July 8, 2018 I had it say 10 without INLET ICE already, sure is strange to throw a message when it went up.
=Panther= Posted July 9, 2018 Posted July 9, 2018 If someone is getting the ice indication at 20 degrees at 8000 feet in the Nevada map with no clouds or moisture (Nevada is already drier than a popcorn fart), then it's definitely a bug. You just aren't going to be in icing conditions with those atmospheric conditions. Maybe in the sim there’s likely no ice, but I do know it gets cold at some the altitudes these fighters fight in Nevada. Leaned on a 370 gallon fuel tank to debrief a pilot discrepancy and it was ice cold. Meanwhile the outside temp was rather warm, certainly above ground ice levels. Fun fact the discrepancy was because the fuel system got too cold and froze the externals. (Not related to engine icing but wanted share the real Nevada experience. Twitch Channel [sIGPIC][/sIGPIC] Virtual Thunderbirds, LLC | Sponsored by Thrustmaster Z390 Aorus Xtreme, i9 9900k, G.SKILL TridentZ Series 32GB, 1080ti 11GB, Obutto R3Volution, Thrustmaster HOTAS Warthog, TPR, Cougar MFDs, FSSB R3L, JetSeat, Oculus Rift S, Buddy-Fox A-10C UFC, F/A-18C UFC, Tek Creations F-16 ICP
Knives Posted July 9, 2018 Author Posted July 9, 2018 Maybe in the sim there’s likely no ice, but I do know it gets cold at some the altitudes these fighters fight in Nevada. Leaned on a 370 gallon fuel tank to debrief a pilot discrepancy and it was ice cold. Meanwhile the outside temp was rather warm, certainly above ground ice levels. Fun fact the discrepancy was because the fuel system got too cold and froze the externals. (Not related to engine icing but wanted share the real Nevada experience.It is a known fact that the higher you go the lower atmospheric temperature you will get. Because what is really heating the air or atmosphere is the earth/ground and not directly by the sun. The fuel temp is way colder because the fuel is volatile and the system is pressurized plus the effect of the OAT. At high altitude even in Nevada the fuel temp could be -20°C or even lower. (high altitude means 30,000ft MSL and above) But the problem with DCS even as low as 8000ft MSL (5000ft AGL) the INLET ICE Warning comes on. So most of the people here think it is a bug. On the other hand, whatever people here were arguing or telling and you too sir was very informative. I think someone from ED has to jump in to either confirm it as a bug or refuse it with an explanation to better understand the Hornet System Operation Procedures.
Ahmed Posted July 9, 2018 Posted July 9, 2018 (edited) Jet engine icing happens only in a narrow margin of temperatures and requires moisture in the air (i.e. clouds, mist or other kind of visible moisture). We are talking about roughly about the 0 to -20C (static air temperature) margin mainly though it may still exist at lower temperatures (up to -40). That's the general consensus. Current caution goes of several thousand feet above the nearest cloud with the ENG page reporting 22 degree inlet temp. So the icing model at least is wrong. But in one of the latest updates they commented that some changes were coming to the atmosphere model as some of the wing vapor effects were going to depend on humidity, so maybe the icing model will be revamped too. Edited July 9, 2018 by Ahmed highlighted the moisture thingy
Nealius Posted July 9, 2018 Posted July 9, 2018 The NATOPS clearly states that an Inlet Temp of +5°C should prevent icing, yet we are getting icing with Inlet Temps way above this....so why has this not been recognized as a bug?
Slant Posted July 9, 2018 Posted July 9, 2018 According to natops, when inlet ice warning comes in, you have to check your AoA as well. You check AoA to prevent ice from being ingested, not to check if ice is actually present, do you not? Perhaps I read it wrong. http://www.csg-2.net/ | i7 7700k - NVIDIA 1080 - 32GB RAM | BKR!
lemoen Posted July 9, 2018 Posted July 9, 2018 PSA: At standard atmospheric conditions (15ºC at sea level, standard pressure) the temperature versus altitude is as follows: As you can see, you get to subzero temperature pretty quickly. Alt(m) Temp (Celsius) 0 15.00 1000 8.50 2000 2.00 3000 -4.49 4000 -10.98 5000 -17.47 6000 -23.96 7000 -30.45 8000 -36.94 9000 -43.42 10000 -49.90
Rainmaker Posted July 9, 2018 Posted July 9, 2018 The NATOPS clearly states that an Inlet Temp of +5°C should prevent icing, yet we are getting icing with Inlet Temps way above this....so why has this not been recognized as a bug? Jet engine icing happens only in a narrow margin of temperatures and requires moisture in the air (i.e. clouds, mist or other kind of visible moisture). We are talking about roughly about the 0 to -20C (static air temperature) margin mainly though it may still exist at lower temperatures (up to -40). That's the general consensus. Current caution goes of several thousand feet above the nearest cloud with the ENG page reporting 22 degree inlet temp. So the icing model at least is wrong. But in one of the latest updates they commented that some changes were coming to the atmosphere model as some of the wing vapor effects were going to depend on humidity, so maybe the icing model will be revamped too. For about the 5th time in this thread...STOP trying to use the engine page inlet temp to justify this. It’s a completely different set of sensors and in a different location. The two are not related.
Ahmed Posted July 9, 2018 Posted July 9, 2018 And for the 5th time too, stop trying to justify the presence of an inlet icing warning in clear air regardless of the temperature (to be honest I dont have a clue about where the inlet temp sensors are located).
Nealius Posted July 9, 2018 Posted July 9, 2018 For about the 5th time in this thread...STOP trying to use the engine page inlet temp to justify this. It’s a completely different set of sensors and in a different location. The two are not related. Right.....because your opinion overrides what's written in the NFM-000....
Rainmaker Posted July 9, 2018 Posted July 9, 2018 (edited) Right.....because your opinion overrides what's written in the NFM-000.... The manuals are correct, you just are not interpreting them correctly. That’s not an opinion. Edited July 9, 2018 by Rainmaker
Nealius Posted July 9, 2018 Posted July 9, 2018 "Inlet Temp of +5°C should prevent icing" leaves absolutely nothing in need of interpretation. That's direct and straightforward.
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