Pilots say they will try to avoid areas populated by farm animals

Engineers from electricity distributor CE Electric began the annual three-month operation on Monday.

They will be conducting low-flying inspections in Northumberland, Tyne & Wear, Cleveland, North, East and South Yorkshire and northern Lincolnshire.

A company spokesman said they would try to avoid areas with farm livestock.

CE Electric said it would be using two helicopters to check the entire network, which supplies electricity to 3.5m homes and businesses in an area stretching from the Scottish borders to Lincolnshire.

'Essential' patrols

The inspections, which are part of the company's �115m annual maintenance budget, should be completed at the end of March, weather permitting.

One of the aircraft will patrol the company's northern region, which covers the Hexham, Penshaw, Cleveland, Scarborough, Malton, Harrogate and York areas.

The other will fly over the southern region, taking in Doncaster, Isle of Axholme, northern Lincolnshire, East Yorkshire and the Selby area of North Yorkshire.

Engineers will check for damage to poles and pylons and use thermal imaging cameras to check the integrity of cables.

Networks inspection manager Gary Bartholomew said: "It is essential we carry out these patrols to check equipment and pinpoint areas where vegetation and trees need to be cut back away from overhead wires, to improve security of supplies to our customers.

"We would reassure farmers and livestock owners that, although the patrols will fly low over overhead wires, the helicopter pilot will try to avoid areas populated with livestock."