Hi I know you are supposed to turn on the engine Anti-ice at 10c or below in visible moister. The problem with that is that I am so busy flying the aircraft and setting the FMC that I forget to turn it on :-). Just some questions that the PIC manual did not clear up for me. Can I just turn on the engine anti-ice on the ground before take-off if I expect clouds on the climb even if it

I wouldn't recommend using anti-ice during take-off or landing unless absolutley necessary. Anti-ice is run by bleed air pulled off of the N2 compressor in the engines, and in turn, the engine doesn't produce as much thrust. If you look at your overhead panel when turning on wing and engine anti-ice, notice the drop in duct pressure.As for knowing when you're in a cloud...most clouds that are favorable for icing are in the lower levels, those levels where you probably will have your landing light on. I know its not very well simulated in FS, but you'll see your lights refracting off of the water particles in the cloud...thus knowing you're in it. If you don't have your LL on, flick it real quick to see...not gonna hurt anyone. Remember though, your AIRCRAFT has to be below freezing for ice to form on the wings, not the outside air. So if you're descending from low temperatures into a cloud of temperatures above freezing, you might get some. On the other hand, if you're taking off from a temperature well above freezing, and climbing into a cloud at a temperature at or just below freezing, you probably won't accumulate any ice.Anyone feel free to correct or add to my explination, as all pilots learn something new every day.

On a related note, the loss of bleed air being pulled off the compressor is the reason why pack flow is often reduced to a minimum at takeoff (or disabled entirely where extra power is needed).While icing can occur at any altitude at any time, it is most common in descents as you pass through visible moisture and on days when those surface temps are near 0C w/ wet, drizzly conditions.One of these days I hope FS technology advances to a point where we can turn on wing lights and visually inspect the leading edges for ice buildup. I imagine we're a ways off yet. Dare to dream, though.J

In the real aeroplane you have to get out of your seat. Even on the 767-200 you can't see the wings from the flightdeck. A good appreciation of airframe icing is to check out the windscreen wipers for ice build up.

You can also check your nuts. The nuts holding down the windscreen that is. Our commercial operations teacher taught us that.

"Can I just turn on the engine anti-ice on the ground before take-off if I expect clouds on the climb even if it

>>The 767 Anti-Ice systems have various safeguards to prevent >>overpressure/overtemperature and EICAS warnings are generated to >>remind the crew to switch them off when the temperatures get a bit >>warm, but you should keep an eye on that temp gauge anyway Are these EICAS warnings in PIC? also do you mean the temp gauge on the EICAS?? and how does the anti-ice operate, does it discharge hot air continually or does it run in intervals? Thank You.:-wave

>You can also check your nuts. Yep, mine are frozen solid. Lol. Randy

:-lol

"Are these EICAS warnings in PIC?"Not sure, November.On the 767 (GE engine), there are overpressure switches in the Wing Anti-Ice ducts which generate EICAS messages. There are WAI overheat switches also, but they don't appear to generate messages... just close the WAI valves. There are also overpressure switches in the Engine NAI systems. These generate "L/R ENG TAI VALVE" Status messages. Actually, I thought the 767 might have 747-400 type ">ANTI ICE" messages which pop up whenever the Anti-Ice is switched on and the TAT is greater than 12 deg C, but my 767 notes don't show this." also do you mean the temp gauge on the EICAS?? "Yes, the TAT indication."how does the anti-ice operate, does it discharge hot air continually or does it run in intervals? "The overhead panel switches open/close valves which allow hot engine bleed air flow into the engine nacelles (the front (intake area) nose cowls) and wing leading edges. The valves open and close to regulate the bleed air pressure into these areas. That is, they can be in any position. However a sensed wing overheat will close the Wing Anti-Ice valve totally, if the aircraft is on the ground.The hot bleed air enters the wing and nacelle areas via pipes and is then fed along ducts (pipes/cavities). These ducts have small holes in them which sprays hot air onto the surfaces to be kept free of ice (from the inside). The used air then vents to atmosphere through other small holes/slots in the wings/nacelles. Venting to atmosphere presumably ensures that hot air is continually flowing throught these areas. I'm not sure, however, if the vented air serves any other purpose, such as heating the surfaces aft of the nose cowl/wing leading edges. Hope this makes sense? (sorry, I don't have any diagrams which would properly show this setup)Cheers.Ian.

Off the top of my head you have to reduce the performance limited takeoff weight by 2300kg for wing-anti ice and 1200kg for engine anti-ice if you want it on during takeoff.

I don't know about the 767, but in the 737-700 CBT, it says that you can turn on Engine anti-ice prior to take-off if initial climb predicts passing through visible moisture and OAT is less than 5C.It also says that wing anti-ice should NOT be used with slats or flaps extended.George DorkofikisAthens, Greece