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Guest DreamFleet

FSX and Aircraft ICE SYSTEM

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This question is more related to the ability of modelling a certain function of an aircraft's anti-ice system. Currently in FS9 if the aircraft you want to model has an anti-ice "AUTO" position there is no way for the aircraft to "know" if it is actually in icing conditions to "activate". Is there a way for this to be addressed?...............Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

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Guest tdragger

What is the definition of icing conditions? You should have access to weather variables already. Seems like this could be done now unless there's some special sauce I'm missing.

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Guest BlueRidgeDx

>What is the definition of icing conditions? Hi Mike,I'm not sure if you're asking rhetorically or not, but if you're really wondering, icing conditions exist in flight at a TAT of 10

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Nick, you do sound as if you were quoting a mathematical formula. All the conditions you are mentioning could be present yet there could be no ice. Mother Nature is far more complicated than this, tdragger perhaps realizes this.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

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Guest Peter Sidoli

I agree with Michael as icing is a very hard thing to predict. Other than for carb icing in a basic single I have never seen visible icing in plus anything.Most icing lies in the band of 0 to -10 deg C. Rain Ice has its own rules.I never liked the fact that aircraft used to break at VNE in MSFS as this appeared as Gimmicky.We all know in reality that an aircraft can dive way beyond VNE with no ill effect yet can break up way before VNE.If MS want to truly model the effects of icing and systems to remove or prevent it then that is fantastic. Icing is one of the major and most unpredictable threats to flight.If its a case of pick a number. Now you have it, now you dont then thats a poor gimmick. In my opinion if icing isnt realistically modelled then forget it altogether.That includes its effect on Lift, Drag and weight as well as effect on thrust. Other areas to consider are air friction.It would also be nice to see it visually modelled building up on the airframe and blowing off with boots :-) They can do effects with smoke why not ice.Peter

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Guest BlueRidgeDx

Okay, well, Bombardier defines icing conditions for the CRJ-200 and CRJ-700 exactly as I stated above...verbatim. It is easily referenced in both the AFM and the POH.I dispatch these airplanes everyday, and if its less than 10c with visible moisture present, I plan takeoff with the nacelle anti-ice on. If its less than 5c with visible moisture, I use both wing and nacelle anti-ice.I have dispatched the J-41, Do-328JET, CRJ-200, CRJ-700, A319, and DC-10. All have had the same icing limitations: less than 10c and visible moisture.You guys are looking at it the wrong way. Meeting the above criteria does not guarantee ice formation, but it is the envelope outside of which, structural icing will not form.Further, I thought we were talking about structural icing. If we're talking about carb icing, then thats a whole separate issue. Carb ice can form even in significantly warmer temperatures provided there is a high relative humidity. The carb's venturi lowers intake pressure and temperature, and given sufficiently low RPM and sufficiently high humidity, can cause ice formation well outside the envelope I mentioned above.Regards,Nick

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>Okay, well, Bombardier defines icing conditions for the>CRJ-200 and CRJ-700 exactly as I stated above...verbatim. It>is easily referenced in both the AFM and the POH.Nick,You are confusing two completely different things: recommended use of anti-ice systems on an aircraft and actual ice formation in flight. Bombardier may have you (wisely) turn on anti-ice systems in certain situations but it does not automatically mean that you would fall out of the sky had you had them off. Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

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Guest BlueRidgeDx

Hi Michael,I'm not cunfused. As I stated, the envelope for structural icing - as defined not only by Bombardier, but also BAe, Dornier/Fairchild, Airbus, and McDonnell Douglas - includes a temperature range from -10C to -40C when visible moisture is present. Barring a cold-soaked wing situation, structural icing will not form outside of this range. Being within that envelope, however, does NOT guarantee icing. Do you see the difference?Also, I never said anything about falling out of the sky just because you're in the icing envelope. I'm not sure where you got that from. Regards,Nick

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>What is the definition of icing conditions? You should have>access to weather variables already. Seems like this could be>done now unless there's some special sauce I'm missing. When one sets anti-ice to "ON" it is on because of pilot input but how does an anti-ice system know to activate from 'auto' to ON when the aircraft 'enters' icing conditions? In other words, the sim does not give any parameters to be read from to activate/de-activate the anti-ice system on it's own because there is nothing to tell it when it's in these conditions. Make sense? ...............Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

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Guest BlueRidgeDx

Everyone,I guess I should also point out, that my answer to tdragger is rooted in the real world, and not meant to construe that structural icing, in its infinite complexity, should or could be modeled in FS.Nick

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Guest Peter Sidoli

NickI think you will have to be more specific for the reasoning on +10 to -40.By that I mean by what methods those figures are come by.Example a jet is on the ground about to takeoff into a 300 foot overcast the temp on the ground is +10.We know that this jet will climb at maybe 3000 fpm ie it wont take long before it is in a temperature where ice will form.Hence in such a situation it would be prudent to turn on ice protection.I can only talk from my own experience, I have never seen ice form at above +3 or below -15.That doesnt mean that there are not rare situations where ice will form. An aircraft structure supercooled in an inversions layer could for a brief time pick up ice while climbing into +10 air mass.An aircraft could pick up rain ice in plus conditions as supercooled particles of water hit the airframe.It is normal to have a higher temp out side cloud only for the temp to drop entering cloud. Usually 3 degrees by experience but maybe more in certain situations.I would like to know the basis of those quoted temp bands which seem more precautionary figures rather than actual ice formation figures.Peter

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Depends on the aircraft and the system it uses. Same with the present autopilot-they all work differently depending on the autopilot model-FS has a "generic" one....I don't fly jets-I fly Ga and my real Baron has deice boots and the system on the Baron works this way:I have a 3 position switch with OFF,MAN, and AUTO. When in AUTO position the deice boots inflate for a period of 5-6 seconds, then deflate automatically and return to vacuum hold down position. The switch must be tripped for each complete cycle. When in the MAN position the deice boots inflate as long as the switch is held in the position-when released the boots deflate. I would love to see this modelled-and see the boots inflate/deflate, and various types of ice (rime, clear etc. ) break off. Pretty complicated to do though-and that is just to model a GA aircraft deicing system. My system also has alcohol for the props and windshield-other models of my aircraft have electrical systems for both.I assume you are talking about a jet aircraft and I have no knowledge of their systems.Shows how complicated it is to model-do they make a "generic" icing system which no one is completely happy about and doesn't duplicate complete reality-kinda like the "generic" autopilot that exists now?http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg

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Guest DreamFleet

Remember, Goef, what the jet has is essentially ice "prevention" (anti ice) via heated wings. What you have is ice "removal" via boots. You cannot prevent ice from forming. The jet can prevent it from forming, as they can keep the wing heated continuously.BTW, take good care of those boots, 'cause you will not like to see the bill for replacing them!As to simulating it in FS, we could do that right now, and we thought about doing it with our Baron. Problem was, many folks expectations that it must be "100% realistic", often without knowing just what "100% realistic" means. Ice comes in different forms, and can accrete at different rates. Affects on flight dynamics can also differ, and we are then faced with dynamically changing the flight dynamics as the plane is flown, not to mention creating different forms of ice, changing accretion rates, and making it look realistic when the boots break it off.Ultimately, we decided that the end result of the level of realism that we could accomplish would not be worth the price of doing so which, of course, would be passed on to the customer.With most, if not all piston-driven GA aircraft with boots, even those that are certified for FIKI, it is still known that once ice is encountered that you should look to leave the area of icing as soon as possible, not stay in it.The fact is, unless your aircraft is certified for Flight Into Known Icing, you cannot legally enter conditions where it could exist, that's the regs. Of course, we all know this is impossible at times to accomplish, thus we have aircraft equipped with boots even though they may not be certified for FIKI. I'm pretty sure that your Baron is not certified for FIKI.In FS, we would have folks staying in icing conditions, watching the ice, then posting "bug" reports in the support forum telling us how this and that does not appear to be "realistic". You'd have people going into spot view and looking at different parts of the aircraft to see if we have ice forming on it, such as antennas, etc.Imagine if we had to simulate clear ice, rime ice, a mix of both, etc. Along with accretion rates ranging from an inch an hour to an inch a minute, then make it look "realistic" as the boots break it off, then having to simulate varying affects on flight dynamics. Afterwards, we would have to provide support for all this, some of which would concern "frame rates".My philosophy is: If you cannot make it close to 100% realistic (I'd settle for 50% realism for icing), then it is not worth doing. The costs of doing it followed by the costs of support later make it impractical.Unfortunately, many folks expect that if you do it, it must be close to if not 100% realistic. When expectations are such, it is best to stay away from it unless you are certain that you can accomplish it.Regards,http://www.dreamfleet2000.com/gfx/images/F...R_FORUM_LOU.jpg

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Guest Peter Sidoli

Lou I know your post was directed at Geof but here is my take anyway ;-)Icing in my book comes very much under the heading of "weather".Take a world devoid of weather and flying would be a very easy occupation.We all know those rare days( In Northern Europe even rarer :-) when you get a clear blue Sky, 50 miles vis and no wind.Weather creates the biggest problem for a mechanical flying machine not only by the fact that the seeing pilot can no longer see but because it challenges the aircrafts ability to fly.As a realism nut for me there are two important parts of a simulation .The first is modelling the aircraft in a way that it reacts and behaves as closely to its real counterpart as possible.The second is that it reacts and behaves in its invironment as close to reality as possible.That means that it should operate in a moving living airmass with winds, air currents, temperatures, density, etc "as close as possible".The sim should then have to deal with the challenges that faced aircraft designers, ie that the pilot enters clouds or poor vis and has to keep the sunny side up while navigating to another strip of tarmac.He has to land on that strip of tarmac without hitting cumulus granitus enroute.The aircraft has to deal with weather and a major part of that weather is aspects of the weather which will destroy the aircraft or stop it flying.Icing is one MAJOR aspect of weather which effects all flying objects which require lifting devices to fly.Manufacturers go to great lengths to keep an aircraft flying when ice is present.Some do better than others. The worst off is the unpressurised GA aircraft which tends to operate in the worst weather, has the poorest performance and the cheapest deicing ability.Reading weather and making descisions becomes all important and one of the biggest challenges of flight. Icing is an integral part of WEATHER.What I am getting at as a realism NUT is that I want realistic flight dynamics and a realistic, living, breathing, moving weather system that challenges me and my aircraft in the sim as it does real world.Visually we are a very demanding lot. If a rivet is out of place or a shape not quite right the forums shout and scream.Why should we be any less demanding on the way an aircraft behaves or the invironment it behaves in?I would pay twice what you charge for an addon aircraft if it oozed realism in every way.;-)Peter

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Yes- I was addressing the comment about the anti ice switch being placed in "auto" or "on" and my point was the results and how one uses it would depend on the type of plane and system used (much like the autopilot of FS which seems to follow no particular model and trys to generically satisfy both GA and jet flyers-and ends up doing neither). Of course my Baron is not known certified-but I've used the boots a few times.....(which were replaced a few years ago-luckily before I got in the partnership!).All the variables of icing would be difficult-but I'd still like to see some progress here in FS. Just the other day I was shooting some practice approaches-out of no where a bank of clouds and snow squall appeared (non forecast of course!) and I started picking a little ice on the tail only-which sublimated when the short squall vanished after about two minutes. I'd love to see an attempt at windshields suddenly icing over,icing on the wing etc.-even if not 100% perfect.By the way-I have been told "unofficially" that any time in the winter there are clouds and conditions are near enough-they will forecast icing -primarily due to law suits that would occur if they hadn't-e.g. safer to just predict icing even if not warranted than miss it and then get sued after the fact.Unfortunately, that makes flying fairly impossible for a good part of the year where I live if one were to take the predicted icing which is in almost every forecast. For me it isn't a problem as I don't fly for a living and prefer not to push my luck. But there are many cargo flyers and instructors around here where I live whose attitude is that if you believed every icing forecast, you'd never be able to fly, and a good part of the time when forecast-it is not there.On the other hand-my dentist who is also a Baron driver-was at 50 f at 5000 ft.-he started his final approach and picked up "1 of clear ice on the way down in a minute(not in the forecast)-there was a temp inversion. Luckily, he had some boots......I'd love to see some of this in Fs....Better get that efb going-I sure am loving mine!http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg

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Guest Peter Sidoli

>The fact is, unless your aircraft is certified for Flight Into Known Icing, you cannot legally enter conditions where it could exist, that's the regs. Of course, we all know this is impossible at times to accomplish, thus we have aircraft equipped with boots even though they may not be certified for FIKI. I'm pretty sure that your Baron is not certified for FIKI.It's interesting to note that New Piper won't sell you ice-protection equipment piecemeal. You either buy the full, approved FIKI (flight into known icing) package or nothing at all

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Guest BlueRidgeDx

Hi Peter,The reasoning behind the temperature range cited is based upon flight test and certification data for the airframe in question. Apparently, it just so happens that many airframes are susceptible to icing within the same general temperature limits, assuming there is visible moisture present.Aerodynamic shape greatly affects the susceptibility of an airframe to ice accumulation. For instance, in the CRJ, we don't have any anti-ice provisions on the vertical or horizontal stabilizers. These surfaces have proven to be "aerodynamically clean" during certification. But again, so there is no mistaking what I'm trying to say, insofar as the CRJ is concerned the POH clearly states: "Icing conditions exist in flight at a TAT of 10

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><we thought about doing it with our Baron. Problem was, many>folks expectations that it must be "100% realistic", often>without knowing just what "100% realistic" means. >>>>Bingo. Give that man a prize! He was not refering to my question Jason since large airliner type aircraft do not have boots. Again, there is no precipitation descriminator in FS's environment so there is no way to know whether the aircraft is in dry, wet, ice, snow or rain unless you can prove otherwise? EDIT- Remember that on the Baron you do not have to worry about any anti-ice EICAS messages, one could simply model "AUTO" as "ON" ALWAYS whereas in the jet you would have to remove your eicas etc messages that the system was "ON" because that is the only way to model AUTO in the current sim so what you would be doing is giving up the visual for a work-around that is not exceptable.....................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

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I'll agree with that. Flying with Weather maker pro in icing conditions brought my plane to a crawl and at one point the mooney stalled and I flat spun into the ground. With downloaded weather, most people probably don't even realize they are in icing conditions most of the time or would realize it if they were. I even saw posts from people on the general forum from people who hoped FSX would model the effects of icing and did not realize FS9 models it pretty well.Interesting about the baron. Maybe a professional edition could include the boots? :)Ian.

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Guest tdragger

I think you missed my point, hence the quote.

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>I think you missed my point, hence the quote.Perhaps I am still missing your point? His reply and your reply should be in regards to my post? You said "bingo" as confirmation to his reply but his statements about what can be achieved regarding simulating the anti-ice does not make it so. Again he is talking about GA aircraft not an airliner with AUTO position modelling.. ...............Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

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Guest tdragger

His comment was to the effect of, "we could do it but people wouldn't like it and they wouldn't know why they wouldn't like it." I wasn't commenting on aircraft specifics.

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