Vortex claims

What do you get when you combine fuildings, commercial jet airliners and still air conditions?

Aircraft trailing wake vortice resulting in vortex damage.

As they fly all aircraft trail vortices behind them which 'roll-up' to form tube-like structures. Vortices are shed continuously during flight from the wing tips, and from the flaps during take-off and landing. The vortex tubes meander through the aird, drifting ground wards and move sideways, at about 5 knots in still air.

The strength of the vortex is related to many factors, these include; airspeed, wing span, aircraft weight, wing lift characteristics and vortex age. But, in general, the heavier the aircraft and the slower it is flying, the stronger the vortices will be.

Under ideal conditions, maximum vortex life is usually no more than three minutes. However, in still air or light wind conditions vortices can persist for long enough to strike buildings below. In effect the vortex will then produce a suction effect removing tiles from the roof, either in small isolated areas in the centre of the roof or often in the form of one or two lines of damaged slates running from eaves level upwards.

On average a trailing vortex which damages property is generated by one take-off or landing in four hundred. Bearing in mind the volume of aircraft traffic at major airports, this would mean over a period of a year a considerable number of hits.

Over recent years our Building Guarantee team have dealt with a number of these claims on behalf of airport authorities, who not withstanding the fact that the liability for the damage is imposed upon the Airline owning the aircraft that caused the damage. They choose to deal with these matters as part of their local corporate responsibility.

In addition to the immediate repairs to vortex strikes we, in conjunction with Oriel, assist in any risk management programme of roof renewal to beet BS5534 in high risk areas beneath Airport flight paths.

For further information about vortex claims, please contact David Robinson, Building Surveying Manager on telephone +44 1489 567830 or mobile +44 7880 780652 or email david.robinson@cl-uk.com