Originally Posted by
Driver 170
Is there anyway i can find out what mixture to use for a freezing point of 10c below OAT?
I do use this app called DeIcing holdover app for IOS.
if using Type 4 Fluid can this be used as a Step 1? Reason i ask, I was on a EZY flight from EDI last Saturday morning at 06:45 and during takeoff roll - green fluid (type 4) came off the wings at high speed as it should. During boarding i seen no de-ice truck. So would this have been done early morning by ground engineers?
You can do a combined step1 (de icing) and step 2 (anti icing) if weather conditions and type of fluid mix permit. Type 1 fluid use has largely been discontinued to to its negative impact on environment, and likewise type 3, due to its corrosive properties to modern carbon fibre aircraft brakes. Hold over time with a type 2 or type 4 fluid can be up to 5 hours at typical 75/25 mix used in UK, so, yes, in your case the deicing would have been done earlier.
https://www.skybrary.aero/index.php/Holdover_Time_(HOT)
Ttfn