APS Aviation releases updated Holdover Times app

APS Aviation has released an updated version of its APS Holdover Times (HOT) iOS app for winter 2021-22.

Based on the deicing research conducted by APS on behalf of Transport Canada and the FAA, the APS HOT app provides pilots with the most up-to-date aircraft HOTs for all de/anti-icing fluids listed and all related guidance.

Holdover times (HOTs) are the calculated length of time that a given de/anti-icing fluid will prevent the formation of frost or ice, or the accumulation of snow, on the critical surfaces of an aircraft so that the aircraft can take off safely.

For the first time this year, the APS HOT app includes Degree-Specific Snow Holdover Times (DSHOTs) for Type II, III, and IV anti-icing fluids. DSHOTs are an expanded set of HOTs at degree Celsius (°C) increments down to the fluid’s lowest operational use temperature (LOUT).

By employing DSHOTs, pilots will be able to stay protected on the ground longer, especially in severe weather. This is because, in many cases, the calculated DSHOT at a specific temperature, such as -4˚C, will be longer than the corresponding HOT given in the ‘paper’ table for a temperature range, such as -3˚C to -8˚C.

“The APS HOT app is the result of decades of experience and research by our team into deicing and anti-icing,” explained John D’Avirro, vice president, aviation services at APS Aviation. “Every fluid is different, so it is vital that pilots know exactly how much time they can wait before takeoff, depending on which fluid has been used on their aircraft and what the weather conditions are at that time.

“APS offers a full customisation service for the app, which we tailor for specific airline and/or operational needs, an approach that is adopted by many airlines each year. There is no one-size-fits-all approach – safety must come first. That is why we spend so much time testing and then analysing the results, and why we release a new version of the app every winter.”

The app

About the 2021-22 HOT app The HOT iOS app incorporates the latest research data to provide pilots with precise HOT information. This lets the pilot know how much time they have to safely take off depending on the weather conditions and the specific de/anti-icing fluids used on the aircraft.

Pilots simply input the relevant parameters and the app calculates the HOT, providing a countdown clock from the minute deicing starts to let pilots monitor progress. Each time the HOT clock is started, an event is created with all pertinent event details. Events are logged on the local device and can be exported via email either individually or in aggregate.