Potential risks posed by refrozen fluids spur calls for tighter regulation

European regional airlines are being warned about the potential risks of refrozen de-icing fluid ahead of the northern winter, with leading industry groups calling for additional regulation.

The European Regions Airline Association (ERA) is to launch an awareness campaign highlighting the issue of using thickened de-icing fluids after many of its members reported problems last year that led to partial loss of control. The association is looking at recommending a change in regulations to ensure ground staff and airlines are trained to carry out de-icing.

Large airliners use complex compounds of de-icing fluids, or type II fluid, that stay as a layer on flying surfaces during ground delays, replacing continuous de-icing practices. They were developed to fly off the surfaces once the aircraft reaches flying speed, leaving the airframe free of thickened fluids.

However, smaller aircraft types typically do not reach a fast enough rotation speed and there has been evidence of fluid remaining on the airframe and even seeping into flight controls, says Nick Mower, ERA general manager for technical services. “The problem is the fluid then dries into powder at altitude, then rehydrates in precipitation and then refreezes upon descent into a gel. This could lead to a loss of control,” says Mower.

The ERA has held four working groups on the issue this year and is harnessing the experience of its members located in northern Europe to draw up guidelines. The ERA is particularly concerned that operators from warmer areas, flying ad hoc missions into northern Europe will be unaware of the issue and trust ground handling companies. The association is looking at a three-pronged awareness campaign, targeting operators, ground handlers and chemicals suppliers. “Aircrew need to be aware of the rotation speed needed to shed the chemical; ground handlers need to know what is safe to apply to smaller aircraft; and chemical suppliers may need to look at the formulation needed for regional types,” says Mower.

The ERA says regulations may need to be amended to ensure that de-icing training takes into account type II compounds. “We are usually against any further regulation, but we feel this could be a critical safety issue,” he says.


Source: Flight International