I'm a little unsure when the correct time to use the Anti Icing systems is?From what I read on the ground at all times the engines are running.What are the times in flight? Is it to do with OAT say between 0 and -10 or something or are there other criteria?Any input would be appreciated.Pete

I think you got it wrong. For example in a 747 you are not allowed to use ant-ice on the ground, I am not sure about other types but I never heard the rule that anti-ice should be turned on on the ground as a rule. Also there are many anti-ice systems - engine, wings, etc.You use anti-ice in flight and only when you see visible moisture **AND** when oustide temperature is anywhere between +5 to -10 Centigrades.On the other hand pitot tube anti-ice is pretty much always left on in larger transport aircraft.Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2http://www.precisionmanuals.com/images/forum/747400.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

In the 737-300/500 (I assume it's similar in the NG), we ran pitot/window heat all the time, engine anti-ice (on the ground or inflight) in visible moisture (clouds, visibility <= 1 mile, or precip), with temps between +10 and -40 C, and wing anti-ice as needed based on actual ice accretion (although it was never used on the ground or before the first power reduction on takeoff).

Ah right..this is from my reading at http://www.b737.org.uk/I am probably confusing the engine anti ice with the wing anti ice.So engine anti ice is allowed on the ground.

I just checked the 744 manual. Wing anti-ice is inoperative while on the ground.Michael J.

Does Ice have any effect in FS9? I've seen options in FSUIPC but I can't say I've had anything that would make me think I've been effected.As much as I like to fly realisticly, I don't see the point with certain things unless they actually have a cause and effect.

NORMAL PROCEDURES1.1 ICING CONDITIONSIcing conditions exist when OAT (on ground) or TAT (in flight) is 10C or below and one or more of thefollowing conditions:

Rule of thumb...visible moisture in the air and an OAT of of 10+ degrees and down... Turn Nacel anti ice on...Wing anti ice I am not sure of...Boaz...

Also on a 777 Wing AI is not used, only airborn under - well icing conditions ;-), you will know if you have ice if it is acculimating on the windscreen post/wipers etc..[h4]Randy J. Smith[/h4]

Nice to see many different procedures among Companies and Constuctors:Our company with MD11All anti-ice when OAT is at or below 6 C and:-Visible moisture in any form is present-OAT and dewpoint are within 3 degrees of eachother (high risk of visible moisture)We have an auto option on the MD11 which controls this. But we switch it to manual ON during descent when we expect icing conditions. Switching it on gives us a higher idle N1/N2.Pitot heat is always on IRL..... If you forget to switch on the heat in FS2004 you will get an airspeed of 0 in due time during icing conditions)Fly safely,Remco

I think this is to prevent overheating of the wing, as the air flowing to the wing's leading edge has a temp around 180

another thing - most aircraft cannot use wing anti-ice with flaps deployed. we run into that problem in the winter in the holding patterns for KEWR and KLGA and KPHL because they are 210kt holding patterns. any icing and we can't use those patterns.Chris Saunders

Interesting Lenny where did you find that out.I fly the 320 for a living in temps of up to 45C and noone has told us nor have we had any problems with bleed leak detectors in those conditions.Be interesting to track it down.Darren Howie

>another thing - most aircraft cannot use wing anti-ice with>flaps deployed. we run into that problem in the winter in the>holding patterns for KEWR and KLGA and KPHL because they are>210kt holding patterns. any icing and we can't use those>patterns.We could use wing anti-ice in the 737-300/500 with the flaps extended...that's a surprising limitation you mention since it's fairly routine to conduct approaches in icing conditions with the flaps extended. Which airlines / types?