I have just started flying EagleSoft's Citation X - which is great, even if it does drag my machine to it's knees. Have done a search on the forum for use of anti-ice on jets but not much luck... At the moment I am turning ON pitot heat & windshield before I taxi, the rest I tend to put on when the temperature goes below zero - however I am sure that this is not the correct useage, can anyone enlighten me to the correct use of engine / airframe anti-ice ??Any details appreciated..CheersG

Sounds about right.There is de-ice and anti-ice. Pitot is anti-ice as is windscreen heat. However, the windscreen heat also helps make the screen more flexible should it be hit by birds, hail, etc.Anyway, de-ice in a jet is usually in the form of hot bleed air from the engines. The bleed air is taken from the second stage of compression so will reduce the EPR (Pressure at Exhaust / Pressure at inlet). A lower EPR is lower power so it helps to reduce the amount of bleed air taken. Therefore, the engine nacel and wing leading edges are generally only supplied with hot bleed air when there is ice to remove. In addition, feeding hot bleed air to those areas on the ground would cause serious problems due to overheating.Hope it helps,Kef.

Kef; That's not exactly correct. Simply put, de-ice is used to remove ice that has already accumulated/is accumulating. It is generally only activated upon entering actual icing conditions. Anti-ice is a preventative measure. It is used to prevent ice from forming in the first place. It is, therefore, turned on prior to entering forecast icing areas, or when conditions might favor icing (e.g. use of engine A/I in clouds or visible precip below 8 deg C). There are both electric and pneumatic de-ice and anti-ice systems. Most jet engine anti-ice systems are pneumatic, using bleed air applied to the nacelle, inlet guide vanes, and/or nose cone fairing. Most wing anti-ice systems are pneumatic, applying bleed air to the leading edges...but there are also electric strip heaters and even pneumatic boot devices that inflate a rubber bag embedded in the leading edge to break ice formations off. Then there are empennage de-icers, windshield heaters etc, mostly electric devices. The bleed source also varies...some jets use bleed air from the low pressure compressor, some from the high-press compressor, and some use both (like the Gulfstream V which uses LP bleed air augmented by HP bleed under high-demand conditions). In general, you should turn on the pitot heat and windshield heat before taxi, as you are doing. Most jets do not allow use of wing A/I on the ground or during takeoff, but do allow engine A/I during ground ops. Typical is to turn engine A/I on if in fog/clouds/precip if temp is below approx 8-10 deg C. Wing A/I is used inflight when expecting icing or if actual icing occurs. One other rule of thumb, activate both wing A/I and engine A/I 10,000 ft prior to climbing or descending through forecast icing conditions. Turn on any deicing systems at first sign of icing. These are general rules...each acft operating manual will have specific guidance.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, DC

In prlonged taxi/queue situations with freezing precip I have found it necessary to turn on structural deicing to prevent build up. Just before I start the take-off roll I turn it off to get max engine power and when established on climb with enough airspeed and agl (gears up) not to require max engine power I enable it again. Not deicing during taxiing prior to the take-off roll has caused me to stall in freezing rain conditions in intial climb due to ice build-up on the ground with twin turbo prop aircraft including a Saab 340B and Beech 1900D.

The better solution is to adhere to the limitations section of most airplanes that prohibits flying in severe icing (to include freezing rain).In general, the only acceptable way of deicing an airplane during ground ops is by use of heated deicing fluid applied by a deicing truck. Aircraft structural ice control systems do not heat entire airframe surfaces, and specifically, ice can build up around the flight controls enough to interfere with free movement. Very bad juju.In FS, the best way to avoid these ice accumulations is to set FSUIPC (full version) and/or your wx add-on to prevent icing. You'd have the truck take it all off before takeoff anyway.regardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, DC

Bob,Errrm, yeah that's what I said??Moreover, hot fluid is generally anti-ice and de-ice fluid is applied cold. Sounds the wrong way around. Anti-ice fluid is very viscous so that it sticks to the airframe for a prolonged period to be effective as anti-ice and so is heated to about 60-70degs to allow it to be sprayed.

One of the payware scenery add-on airport collections has three or so airports with deicing stations. I suppose they could be functional.I probably should have stated that the condition I was describing was a drizzle at slightly asove freezing that might form ice on contact with the cold metal.You are correct in that for smaller commercial commuter flights that in severe icing they would probably be cancelled, but in lighter conditions I think they would probably go. Anyway, for my purposes, I'd rather do the extended taxi distance with structural de-icing on just to work around FS limitations of no working deicing stations than to eliminate the effect entirely.Perhaps a scenery macro could be designed or even an AFCAD placed object that would place a deicing station effect on the airport layout, similar to the auto fuel station fill, that could clean up the aircraft before the hold short points.I usually fly in IMC, unless I'm sightseeing in GA, equipping the commuter panels with functional radar to give me a more immersive experience dealing in weather avoidance navigation and techniques when appropriate to give variety to each flight.

I am a strong believer in trying to achieve reality in the sim hence the motto "if you cant do it properly dont do it at all".For me icing is poorly modelled in FS as are many weather conditions.I would rather a living weather invironment was worked by Microsoft and its effect on the aircraft was accurately modelled.Otherwise we end up with gimmicks and the whole experience becomes gamey.Just a thought??Peter

Kef;Well, no, not exactly what you said. I think if you look, you'll find that most true aircraft de-ice systems are electric rather than pneumatic, and that most aircraft wing heating systems are anti-ice systems and not de-ice systems.I think you have it backwards...deicing is done with heated fluid, anti-ice fluids are put on unheated so they stay thick and stick better.From http://pubs.acs.org/cen/whatstuff/stuff/7901scit5.html"Deicer performance is measured by holdover time, which is the length of time an aircraft can wait after being treated prior to takeoff. For Type I fluids, the holdover time is only about five to 15 minutes, so the aircraft has to take off right away or else wait to be deiced again.When a longer holdover time is needed, a two-step process is used in which deicing is followed by treatment with an anti-icing fluid. Anti-icing fluids can be either Type II or Type IV, although Type II is slowly being discontinued in favor of Type IV. Type III anti-icing fluid, designed for small commuter aircraft, is no longer used. The anti-icers, which are sprayed on unheated, are 65% glycol and usually are not diluted further. They contain a sufficient amount of a polymer thickener to enable a heavier layer to be applied. For Type II and Type IV fluids, the holdover times are about 30 minutes and 80 minutes, respectively."RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, DC

Hi Bob,In Canada we use Type I for De-Icing and Type IV for Anti-Icing. Where I live about 6 months of the year will require some form of De/Anti-Icing. You are also correct in stating that De-Icing Type I fluids are applied heated and we use a 60/40 glycol/water ratio. Our Type IV is a new environmental fluid that is pre diluted so we don't add anything to it or our hold over times are invalid.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Re the de-icing fluid: Yup! You're correct. It appears my training course and, less so, the UK CAA documentation was out of date. I have emailed them and the CAA appears to be updating their information.Its good the learm!

>I am a strong believer in trying to achieve reality in the>sim hence the motto "if you cant do it properly dont do it at>all".>>For me icing is poorly modelled in FS as are many weather>conditions.>I would rather a living weather invironment was worked by>Microsoft and its effect on the aircraft was accurately>modelled.>>Otherwise we end up with gimmicks and the whole experience>becomes gamey.>Hi Peter,I'm very much in agreement with this. Let's get these kinds of features modelled well and then move on to more 'gimmicky' items.That's not to say I don't dream of great eye candy and other kinds of icing on the cake, if you'll excuse the pun!

Sure. But until then, do we only fly CAVOK? That is not realistic either.I use AS2004.5 for weather and the application is constantly being improved to work around admitted faults in the FS9 weather rendering. It gets closer all the time to providing realistic challenges. What is provided does not appear gimmicky and works most of the time providing visual and flight dynamics effects. Weather does dynamicly change and I want the experience of operating aircraft (or not!) through various conditions as happens in the real world. In my application I archive interesting weather situations (downloaded real weather).Regarding pitot icing, I have seen the IAS slowly drop, not suddenly dump to zero. Not too gimmicky there.Same with structural icing.I'd rather have some of these effects modeled rather than none even if not done perfectly. It keeps me alert to what is needed to conduct aircraft through various conditions and what will happen if I do not heed the cautions required for the environment at hand.It is nice that adverse weather and the effects on aircraft are not ignored in this sim. We can only hope for improvements in this and all areas by MS and the third party developers that are doing well to coax maximum realism out of the sim working within its limitations.There were two main reasons I upgraded from FS2K2 to FS9:1. Local weather manipulation as opposed to a global environment everywhere at the same time. You can see weather building ahead if you are above the cloud layer or varying density of cells of embedded storms if using a radar product such as modeled by Reality-XP.2. The use of parallel runways by AI. Now with a workaround by the PAI/AFCAD folks, simultaneous non-parallel ops can be performed by AI.The point is, things are improving.Right now, engine deicing, prop deicing, and structural anti-icing do not appear to be modeled seperately. We do have seperate carb heat for non-turbine aircraft that is modeled.