Holdover Time
The estimated period during which an applied anti-icing fluid will prevent the accumulation of ice or snow on treated aircraft surfaces.
Full Definition
Holdover time (HOT) is the estimated duration for which an anti-icing fluid, once applied to an aircraft, will remain effective in preventing ice or frost from forming or accumulating on aerodynamic surfaces. HOT is determined by fluid type, ambient temperature, and weather conditions (e.g. snowfall rate, freezing rain intensity) and is published in standardised HOT tables issued by regulatory authorities and the SAE International. Editors must write 'holdover time' as two unhyphenated words unless used as a compound modifier ('holdover-time chart'). The abbreviation HOT should be spelled out on first use. Confusion with 'ground icing time' or 'clean aircraft concept time' should be avoided.
Usage
Usage note: Two words as a noun phrase ('holdover time'); hyphenate only as a compound modifier ('holdover-time guidelines'). Always define HOT on first use.
In Context
- "The crew confirmed that the holdover time had not expired before commencing the take-off roll." — De-icing compliance checklist
- "HOT tables for Type II fluid must be updated each season in accordance with the current SAE guidelines." — Winter operations manual