Holdover Calculator
This is the disclaimer every pilot accepts in the app before first use. It is published here for reference.
Disclaimer version 1 — effective June 12, 2026
Holdover Calculator is an advisory tool only. It is not an approved regulatory document, not certified as an Electronic Flight Bag (EFB) component, and not a substitute for the official Aircraft Operating Manual (AFM/POH), the operator's approved deicing/anti-icing program, or current guidance issued by the FAA, Transport Canada, or any other civil aviation authority having jurisdiction over your operation.
The pilot in command is solely responsible for selecting an appropriate holdover or allowance time, performing pretakeoff contamination checks where required, verifying that the fluid actually applied to the aircraft matches the entry chosen in this app (brand, type, dilution, glycol base), and recognizing conditions in which published times do not apply or are exceeded. Nothing in this app overrides the operator's procedures, the PIC's regulatory obligations, or the requirement that the aircraft's critical surfaces be free of contamination at takeoff.
The accuracy of every calculation depends on the accuracy of the inputs. In particular, the aircraft rotation-speed category (the SAE AS5900 aerodynamic test classification) is established by the aircraft manufacturer and published in the AFM / AFM supplement, manufacturer service letters or winter-operations bulletins, or the operator's approved deicing program. It is the pilot's responsibility to determine and select the manufacturer-established category; this app cannot verify it. An incorrect category changes which Lowest Operational Use Temperature applies and whether ice-pellet allowance times are available, without any visible error.
Holdover and allowance times are statistical estimates of anti-icing fluid effectiveness under typical test conditions. Actual fluid life can be reduced by factors not modeled in this app — including wind, taxi-induced airflow, precipitation intensity exceeding the assumed band, contamination from deicer overspray, refreezing of fluid that has run off heated wing surfaces, and aircraft skin temperatures different from the outside air temperature. When conditions are non-ideal, plan for the lower end of any published range and shorten further as required by your operator's procedures.
METAR, location, and day/night data shown in the app are fetched from third-party providers (including NOAA Aviation Weather and the device's location services). These feeds may be delayed, incomplete, or temporarily unavailable, and they may not reflect conditions at your specific apron or runway. Always confirm conditions visually and against your operator's authorized weather sources before commencing taxi.
Regulatory holdover charts include footnotes that govern: the 90-minute takeoff window after precipitation stops for ice pellet allowance times; prohibitions on takeoff when outside air temperature decreases during the takeoff window for certain fluid/precipitation combinations; restrictions on the use of any fluid below its Lowest Operational Use Temperature (LOUT); and combinations for which no holdover time has been published. This app surfaces the chart notes it knows about, but you must read the original FAA or Transport Canada Holdover Time Guidelines to understand every condition that applies to your operation.
Where the calculator does not list a specific fluid brand or version, do not assume an unlisted fluid behaves like a generic Type I, II, III, or IV entry. Consult the fluid manufacturer's product data sheet and your operator's anti-icing program. Generic Type IV entries in this app reflect the most conservative published times for the fluid type and may not reflect the performance of the product actually on the aircraft.
This application is provided “as is”, without warranty of any kind, express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, accuracy, completeness, currency, or non-infringement. To the maximum extent permitted by law, the developer and contributors disclaim all liability for any direct, indirect, incidental, consequential, special, or punitive damages arising from the use of, or inability to use, this application — including but not limited to operational delay, regulatory action, or property damage.
Holdover Time Guidelines are revised annually by the FAA and Transport Canada, typically before the start of each winter season. Verify that the source documents listed in the app match the effective dates currently published by your civil aviation authority. If they do not, do not rely on the values returned by this calculator and consult the current published tables directly.
Version 1 (June 2026, app version 2.0) — initial published disclaimer, including the aircraft rotation-speed category responsibility section introduced in app version 2.0.