Quietgentleman

There is no magical temp needed for deicing. You can do it at 33 degrees if the ice build up is super slow. Its the formation of ice and how fast if forms that will determine how high a temp you will need to keep your wing ice free. As far as bleed air is concerned on the biz jets they are only heating a short area of leading edge which is usually directly in front of the engines. This is done cause the jet engine absolutely will not take ice being injested into the compressor section. They are running extremely high tempuratures and thats why the leading egde of the wing in that area and around the engine nacelles are stainless steel. QGM