should i turn while on cruize (when the temperature is lower)? or there's an specific temperature for turning it on?

Forum search function is your friend: http://forum.avsim.n...e/page__hl__ice

Hi,ON THE GROUND:If TAT is +10 °C or below and you are in visible moisture (mist/fog/precipitation), then switch engine anti-ice on. Remember that as air enters the air intake, as a result of the reduction in pressure the temperature of the air entering the engine inlet will drop considerably and can result in intake icing. When you apply TO thrust this ice can break off, enter the engine, and cause damage/flame-out if severe enough.IN THE AIR:If TAT is +10 °C or below and flying in visible moisture (e.g. precipitation/mist/fog/clouds).If SAT (note the change to SAT!!!) is below -40°C then it is considered unlikely you will accrue icing so use of anti-ice systems is not necessary, as the water droplets in the air will be in a frozen state.Note that super cooled water is a big killer. SAT can be at -30 °C but the water droplets are still in a liquid state until they contact something (anything) then they instantly freeze solid.Another point to note about icing is that whilst the aircraft is free of ice it is less likely to start icing, but once ice starts to build, the progression can be rapid (seconds not minutes), so stay vigilant.If you do encounter icing and your anti-ice/de-ice systems can not cope then the quickest ways to exit are to descend if able to warmer air and turn around and fly out of the conditions. Note that flying out of the conditions is not always possible, either laterally or vertically.The biggest killers are ice on the wings and tailplane. Once you change configuration (e.g. extend the flaps), the tail icing shows itself, but it may be too late. There is a great video by NASA on this problem as it relates to the Twin Otter - it is an eye-opener.

Best regards,Robin.

Hi,ON THE GROUND:If TAT is +10 °C or below and you are in visible moisture (mist/fog/precipitation), then switch engine anti-ice on. Remember that as air enters the air intake, as a result of the reduction in pressure the temperature of the air entering the engine inlet will drop considerably and can result in intake icing. When you apply TO thrust this ice can break off, enter the engine, and cause damage/flame-out if severe enough.IN THE AIR:If TAT is +10 °C or below and flying in visible moisture (e.g. precipitation/mist/fog/clouds).If SAT (note the change to SAT!!!) is below -40°C then it is considered unlikely you will accrue icing so use of anti-ice systems is not necessary, as the water droplets in the air will be in a frozen state.Note that super cooled water is a big killer. SAT can be at -30 °C but the water droplets are still in a liquid state until they contact something (anything) then they instantly freeze solid.Another point to note about icing is that whilst the aircraft is free of ice it is less likely to start icing, but once ice starts to build, the progression can be rapid (seconds not minutes), so stay vigilant.If you do encounter icing and your anti-ice/de-ice systems can not cope then the quickest ways to exit are to descend if able to warmer air and turn around and fly out of the conditions. Note that flying out of the conditions is not always possible, either laterally or vertically.The biggest killers are ice on the wings and tailplane. Once you change configuration (e.g. extend the flaps), the tail icing shows itself, but it may be too late. There is a great video by NASA on this problem as it relates to the Twin Otter - it is an eye-opener.

Best regards,Robin.

thank you very much dude, you helped me a lot, excelent answer.