We use cookies to improve your experience on our website. Accept | Find out more


Ask the Pilot, with Captain Mike Bowers


Q: Could you explain the purpose of deicing a plane?
A: We deice aircraft to ensure all snow and ice are removed prior to flight and to prevent any snow still falling from adhering. We only use two of the four types of deicing fluid: Type I and Type IV. Type I is a propylene glycol–based fluid and is mixed with hot water at a preset ratio to remove any ice or snow already on the aircraft. It has a limited “hold-over” time, so after applying Type I, we then apply Type IV, which is also a propylene glycol–based fluid but is thicker and is more effective in preventing continued snowfall from adhering. If it is not snowing, and we just need to remove snow, we only use Type I.

Do you have a question for Captain Bowers? You can write to him at askthepilot@united.com

Leave your comments