Helicopter aerial inspections

Each year we inspect about a third of our 11kilovolt (kV) line network, plus our whole 33kV network by helicopter for faults and hazards, and to see what condition the poles and wires are in. 

Using helicopters is fast and cost-effective and provides us with a birds'-eye view you can't get from the ground, for example, a loose cross-arm bolt or rot at the very top of a pole. Inspections are critical for safety and to ensure reliable power supply to our customers.  

While our lines inspectors physically check power poles at scheduled intervals - even in the most remote locations - the helicopter checks allow us to monitor poles, lines and other assets between those ground inspections made on foot.

Trees and vegetation come in for special attention during the flights. Trees are a real challenge because 60 - 70 per cent of power outages are due to trees falling on lines.

Any issues seen are noted, photographed and logged against the helicopter's GPS so they're easy to action, whether that's an urgent fault, something for planned maintenance or bringing a tree to an owner's attention. 

All flights follow strict safety and operational procedures. These include a reconnaissance to identify hazards to avoid, such as transmission lines and areas with livestock or people working. This is followed by an inspection flight 20 metres above and to the side of the line.

Inspections are deliberately delayed until after calving and lambing to minimise any impact on stock, while faults flights are made as required. We use two local helicopter companies, Heli 1 and Western Helicopters.

You'll find updates on the areas we're flying on the faults and outages page of our website.