Airways investigating why its Wellington Airport system couldn't handle deluge

Airways is probing why a system to help planes land at Wellington failed in heavy rain. Photo / Mark Mitchell

Airways is looking at ways to avoid a repeat of disruption at Wellington Airport caused by surface water on the runway interfering with signals sent to planes.

Heavy rain that hit the capital meant the Instrument Landing System at the airport was disrupted, forcing the suspension of flights last night.

Further testing of equipment showed the systems were operating correctly, however the surface water on the airfield interfered with signals being transmitted.

It is an important tool for allowing pilots to land safely when visibility is low and in bad weather and is constantly used at Wellington Airport.
 
The equipment is located on the runway.

"Last night, while the ILS was functioning correctly, excessive rainfall and surface water around the airfield caused some disruption to the signals being sent out and received by the system," a spokeswoman said.

''This level of surface water experienced last night was extraordinary."

The disruption has been known to happen occasionally world-wide but it is a highly unusual event in New Zealand, says an Airways spokeswoman.
 
''As with any adverse event, there will be a follow up review where we will look to assess the likelihood of this happening again and what could be done to prevent it," she said.

Service was resumed in time to allow an international flight to land at 12.44am.

Wellington airport warned this morning that although flights were operating passengers should expect some delays following last night's cancellations and diversions.