Can somone help me with when exactly I should use Anti Icing in FS. I guess in my mind it should be when you are in precipitation and the temp is below freezing. I am not sure how this relates in FS. I have heard both that icing is or isnt modeled but I am not too concerned about that since if I know the proper procedures I can avoid icing all together. So I guess in a nutshell I am asking what conditions need to be present for me to use Anti Ice as it relates to MSFS.Thanks Andrew

As far as I can remember, ok, you use anti-ice when there is freezing rain or freezing showers. This condition to be concerned about is where the collecting surfaces are below freezing, but there is no snow.. the rain collects very quickly on leading edges. I suppose you can have collecting surfaces below freezing when descending very quickly from upper altitudes through rain, or (of course) the air temps are below freezing (but there is rain).In real life you use if you notice icing anywhere on the cockpit windows or surfaces you can see, or you note the outside temps are below freezing and there is rain of any kind, or you start losing lift you can certainly suspect ice or frost as responsible.I suppose you also use it when you are also concerned about frost, which collects when your airplane surfaces are below freezing, and the air is at the dewpoint -- usually when you are going through clouds with supercooled moisture droplets. Different kinds of ice can form: kernel ice, rime ice or milky ice .. on the surface the air temp is usually above dewpoint. As you get higher the air temp usually drops (unless there is a temp inversion). The base of clouds should be where temp=dewpoint.Pitot heater is also important unless you don't care about a functioning airspeed indicator :)none of this appears to be modelled with fs9 but i'm not a long time user so perhaps someone else knows better.

FS9 does indeed model icing...it just doesn't do it well. But an aircraft in icing without anti-ice/deice will accumulate weight in FS, and in severe icing, you will accumulate weight and see your pitot probes ice up even with all the heaters on (not too realistic, especially with the probe heat on).I recommend using FSUIPC to disable severe icing, and also enabling the "allow FSUIPC to interfere with FS own weather" options to prevent FS from morphing the wx into a random severe icing event.In general, in real life, and as I like to fly my birds in FS,you use anti-icing systems in advance of encountering forecast or known icing conditions, or at the first sign of conditions favorable for icing...including induction icing which can occur at temps above freezing. Generally this means any time you're in visible moisture with temps below approximately 10 deg C. Visible moisture includes fog, clouds, and any sort of precip. Deicing systems are generally used only when actually encountering icing conditions as indicated by warning systems aboard the aircraft or by visual observation of ice buildup.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, DC

It's important to keep in mind that the systems modeled in FS are "anti-ice," with the exception of pitot heat which actually will "de-ice" a frozen pitot tube's venturii.Once you've accumulated ice loading on the a/c in FS, it's too late to turn on the anti-ice systems... ;)A few clever gauge programmers have managed to kludge together some code that will "sort of work" like de-icing boots, but they are still largely ineffectual.

Okay, guess I have to ask a question here.As winter progresses (the Pacific NW) I have been in the habit of turning on anti-ice and pitot heat automatically. I just turn them on right along with the nav lights and such. This is before I even taxi. Does this practice cause any problems? I haven't noticed any but then I'm not sure if I'd see anything even if it rose up and bit me. :D

It's hard to define a single "rule to follow" with regards to the use of anti-ice systems, but it is interesting to note that on most a/c that normally fly at high altitude, turning on the pitot heat is part of the normal checklist.On the Citation jet line, for example, other anti-ice systems are listed on the before takeoff checklist simply "as required," which essentially leaves it up to the PIC to make that determination... :)Keep in mind that many anti-ice systems depend on bleedair from the turbines to work, so the trade-off costs of engine efficiency loss vs. the possibility of ice formation must be weighed carefully...

Actually the Pitot heater is really anti-ice as you leave it on, as is the windscreen heater. Indeed, it is universal practice to switch the pitot heat on just before take-off on anything from the 152 to a 747.Wing boots, prop boots, prop fluid, bleed air can all be classed as de-ice as they are generally only operated when ice has actually formed...with the posible exception of bleed air on some systems.Regardless, bleed air cannot be used on the ground as it is so hot, that without the high speed air passing the leading edge it will simply melt distort and weaken the wing. In addition, it reduces the engine EPR (power) which is often unacceptable for take-off. Not modelled in FS.With regard to wing and prop boots, leaving them on makes them useless as a cavity will form in the ice so an inch or two is allowed, which is then cracked off by the expanding boot. In both cases wing and prop performance drop. FS does model this to some degree.Thereare electric prop de-icing systems available on most modern turbo-props. These could also be classed at anti-icing.

Thank you to every one that replied. I guess I was looking for an easy always put it on when... but as Bill has stated there is no such thing. It seems there are a few factors to be determined when flying as to use or not to use Anti ice or de-ice equipment. Thankfully there should not be any severe consequences in FS if I should happen to miss a step or sign once in awhile. I will probably take the suggestions and apply it to my checklist for different aircraft.Thanks againAndrew