Holdover Times Calculator

The holdover time (HOT) calculator provides estimated time that deicing/anti-icing fluid will prevent the formation of frost or ice and the accumulation of snow on the critical surfaces of an aircraft. It help flight crews make decisions.
Holdover Time begins at the start of the anti icing operation. If a two-step operation is used, then it begins at the start of the final (anti-icing) step. By definition therefore, holdover time will have effectively run out when frozen deposits start to form or accumulate on treated aircraft surfaces.