Large-scale tests of runway deicing agents at Ørland airport

Runway deicing agents are used to ensure sufficiently high friction on runways in winter conditions. The friction coefficient is a number between 0 and 1. The lower the friction coefficient, the smoother the surface. The requirements for friction on runways are normally 0.3 to 0.4. Runway deicing agents containing the sugar product betaine may be an alternative to using formates/acetates or urea. Betaine is less corrosive than formates and acetates, and emissions of betaine have a lower environmental impact than urea. A study conducted by FFI showed that betaine-based deicing agents had similar melting capacity to urea, but less than Aviform, in laboratory tests. In order to gain more knowledge about how betaine-based deicing agents works in practice, it is necessary to perform large-scale tests under real conditions. The present study includes large-scale tests of the betaine-based runway deicing agents Betafrost L Plus, Betafrost G and Nutristim at Ørland Airport. The effect of the runway deicing agents was compared to the effect of the formate-based runway deicing agent Aviform L50 and urea. Seven tests were performed during the winters of 2020 and 2021. The effect of the runway deicing agents were determined by how much the friction on the test fields increased after application of the runway deicing agents. In addition, how the runway deicing agents affected the mechanical removal of snow and ice was also taken into account. Employees at the Fire and Rescue Service at Ørland Airport performed the tests. Both types of liquid deicing agent (Aviform L50 and Betafrost L Plus) worked well at around 0°C, but worked relatively poorly at <-5°C, but in combination with mechanical treatment, friction of >0.35 was achieved in all cases. Tests with solid deicing agents were performed at <-5 ° C, and generally showed poor effect for all the deicing agents tested (urea, Nutristim and Betafrost G). Betafrost G (solid) was also tested at 3°C, and showed better effect than the other tests. The tests showed that there was little or no difference in the ability of Aviform L50 and Betafrost L Plus, and betaine and urea granules, to increase the friction on the test field. A limited number of tests were performed in this study, but the results indicated that betainebased runway deicing agents are good alternatives to Aviform and urea. None of the deicing agents work well enough on their own, and in order to achieve high enough friction on runways, it is necessary to carry out sufficient mechanical treatment at the right time. It is recommended to perform additional tests to gain more knowledge about how betaine works under real conditions, and what can be done to optimize its use.