Posted 22 September 2020 in Aviation, News.
  • RHEA Group company APS Aviation, world leader in aircraft ground icing research, releases new version of unique APS Holdover Times app for winter 2020-21
  • Available now for download from the Apple App Store or for customization by APS under contract
  • Trusted by over 45,000 pilots globally every year

22 September 2020 – APS Aviation today released the new version of its unique APS Holdover Times (HOT) iOS app for winter 2020-21. Based on the company’s extensive de-icing research and decades of experience, the app provides pilots with the most up-to-date aircraft ground fluid holdover times and related guidance, developed by APS on behalf of Transport Canada and the Federal Aviation Administration (FAA).

The 2020-21 APS Holdover Times app can be downloaded from the Apple App store using this link.

This version replaces the 2019-20 HOT app, with holdover times for de/anti-icing fluids that will be in use by pilots globally during winter 2020-21. The ‘holdover time’ is the calculated length of time that any particular fluid will prevent the formation of frost or ice, or the accumulation of snow, on the critical surfaces of an aircraft so that it can take-off safely.


About the 2020-21 HOT app

The HOT iOS app incorporates the latest research data to enable pilots to understand how much time they have until they can safely take off, depending on the local temperature and weather conditions, and the specific de/anti-icing (or generic) fluids used on the aircraft. Pilots simply input the relevant parameters and the app calculates the holdover time, providing a countdown clock from the minute de-icing starts to let pilots monitor progress before take-off.

Each time the HOT clock is started, an event is created with all pertinent event details. Events, which are logged on the local device, can be exported via email, either individually or in aggregate, or deleted.

Pilots can purchase and download the app from the Apple Store, installing it immediately for use. The app includes full training information but is designed with ease-of-use in mind, so most people can use it with little or no training. The HOT app also enables easy access to HOT documents through a PDF viewer.

APS also offers a full customization service for the app, which can be tailored by APS for specific airline and/or operational needs, an approach that is adopted by a number of airlines each year.

“The APS Holdover Times app is the result of decades of experience and research by our team into de-icing and anti-icing,” explained John D’Avirro, Vice-President, Aviation Services at APS Aviation Inc. “Every fluid is different, so it is vital that pilots know exactly how much time they can wait before take-off, depending on which fluid has been used on their aircraft and what the weather conditions are at that time. There is no one-size-fits-all approach here – safety has to 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.”


About APS Aviation

APS Aviation, a RHEA Group company based in Canada, is the world leader in aircraft ground icing research and the testing of de/anti-icing fluids. For over 25 years it has worked closely with regulators, global standards organizations, partners and industry peers, and it has been responsible for developing and managing the holdover timetable data and guidelines on behalf of Transport Canada and the FAA for the last two decades. The company has prepared over 200 technical reports on behalf of Transport Canada and the FAA.

Canada provides the ideal base for APS because the country’s extremely large size and location enable the APS team to test de/anti-icing fluids in a wide variety of winter weather conditions and temperature bands. APS’s experienced group of testers travel across the country for up to 6 months to carry out tests on both new fluids and commercially available ones that are due for retesting. The different properties of each fluid enable aircraft to spend differing amounts of time on the ground after application before still being able to take off safely. Thorough testing across all combinations of temperature and weather is vital because these factors also affect the time before ice starts to form again on an aircraft’s wings and tail, which causes their aerodynamic properties to change.

APS Aviation Inc. is a RHEA Group member company and a subsidiary of RHEA Inc.


Find out more

Download the app: The 2020-21 APS Holdover Times app can be downloaded from the Apple App store using this link.

App customization: Please contact the APS team for more information at

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