Safe positioning of power pylons

The Dutch power company TenneT plans to build a new 380 kV high-voltage transmission line. A section of the envisaged line of pylons runs alongside Schiphol’s Polder runway, following the route of an existing 150kV transmission line. NLR-ATSI analysed the potential risks to flight safety.

In 2010, TenneT asked the NLR Air Transport Safety Institute (ATSI) to chart the difference in terms of flight safety between the existing pylons and two optional routes for the new transmission line. The outcome will enable the authorities to decide which route is preferable in terms of safety. The new high-voltage line can involve more serious safety risks than the existing line. The planned route runs closer to the Polder runway, and some of its pylons are higher. Normal air traffic is at a sufficient distance from the pylons, but for an aircraft in trouble they can possibly represent a physical obstacle. The new line may also affect the behavior of birds around Schiphol, with potential risks to air traffic. Furthermore, the higher voltage of the line may interfere with avionics, communication equipment or other electronic equipment.

The analysis produced by NLR-ATSI and Eindhoven University of Technology, reveals that the two potential routes are virtually identical in terms of safety risks. Differences in the risk of physical obstruction caused by the planned grid line or in the chance of collisions with birds are deemed to be insignificant.

The outcome with regard to interference with aviation electronics is less unequivocal. Owing to the complexity of this issue and the absence of certain required system data, futher research is needed.