Folks in the northern hemisphere aren't thinking about it too much right now, but in a few more months, the SAS Group's five airlines will switch to a newly developed de-icing fluid. Together with the manufacturer Kilfrost, SAS has succeeded in producing a deicing liquid that does not contain Triasol, a substance that takes considerable time to be broken down and that, many say, accumulates in the food chain.

Each year the SAS Group's airlines use over a million gallons of deicing fluid. Most of the fluid is collected in conjunction with deicing and is reused after processing in a purification plant. However, a significant percentagd of the fluid does remain on the aircraft, to be spread out over the airport and the surrounding area.

Greener goop

"SAS is the first airline to develop a deicing fluid with significantly better environmental properties than previously. We hope that other airlines will follow our example and begin using deicing fluids without Triosol," says Niels Eirik Nertun, Environmental Director at SAS.

The requirement to eliminate Triasol originated with the Norwegian Pollution Control Authority (SFT). In other Scandinavian countries, Triasol is still an acceptable component in deicing fluids.

This pseudo-plastic glycol solution (primarily propylene glycol with high molecular polymers added as a thickener), Kilfrost Type II - ABC 2000, has been around for just over three years. (Kilfrost also makes a Type I and a Typr IV deicing product.) Type II fluids get runny when sprayed, or when the aircraft moves; but in a "static" state (as when sitting on a wing), it forms a more-viscous layer, with an economical (especially when diluted 75/25%) HOT (Hold Over Time).

"We have elected to introduce the new deicing fluid on a broad scale and not to wait for new regulations in Denmark and Sweden. The new fluid is SAE-approved, and we hope that it will become a standard product on the market," continued Niels Eirik Nertun.

Triasol was used to protect against rust, but following an extensive research and development effort, it was possible to replace it with a substance with less environmental impact.

SAS will introduce the new deicing liquid in all airlines within the SAS Group as of Autumn 2003.

FMI: All About De-icing; Kilfrost