'We continuously observe weather conditions, interpret weather predictions, and monitor the sensors that indicate temperatures on runways, both on the surface and in depth. This allows us to predict weather conditions 6 to 8 hours in advance', explains Jani Elasmaa, the head of Helsinki Airport's maintenance unit from Finavia.
Helsinki Airport operates a strategic snow clearance fleet that includes some 60 vehicles and other equipment. Their brush blowers, based on Finnish expertise and design, are worth special attention.
'Along with the manufacturers, we have been developing an efficient brush blower vehicle suitable for use on runways. After decades of work, the current model is 25 m long, weighs 32 tons, and is able to plough an area of up to 9 m in width', Elasmaa explains.
The price of one of these monsters with all attachments amounts to roughly a million euros.
Clearing one runway of snow in 10+ minutes
The runways are cleared of snow one at a time. Nine or ten brush blower vehicles run side to side on a runaway that is roughly 3 km in length and 60 m in width. It takes this crew 11 to 12 minutes to clear one runway from end to end.
Snow banks forming on the runway edges are then lowered using 1,000+ hp snowblowers with four-wheel steering.
'We can't allow the snow banks grow too high, because aeroplane wings could then come in contact with them', Elasmaa points out.
Over 100 employees operate the snow clearance vehicles and equipment on the runways and other airport areas. The fleet is maintained by the unit's own repair shop, and is also able to produce spare parts when needed.
Internationally recognised snowhow
Finnish snowhow is renowned elsewhere in the world too. Both experts of the sector and TV crews have often visited Helsinki Airport to see how Finavia deals with wintertime maintenance tasks.
All are amazed to see the airport's tailor-made snow clearance fleet, as well as the methods applied.
'We have about 26 different brushing patterns for the runways, selected on the basis of departing and arriving traffic flight directions. Each brushing pattern comes with its own carefully defined start and end points and duration', Elasmaa continues.
'We always agree upon the brushing pattern beforehand with air traffic control. They are our most crucial partner in ensuring the traffic flows properly and the airport is kept open'.