More than 2000km of power lines are being checked in the region from today.
Low flying helicopters will view north of the River Tees as well as west of the A1 in Yorkshire.
Farmers and landowners are being warned in case the inspections affect livestock in fields where power lines cross.
Search and rescue helicopters, including Sea Kings operating out of RAF Boulmer in Northumberland, are set to be replaced by a new fleet operated by an American company.
Under the new contract operations will end at RAF Boulmer and 22 new state-of-the-art helicopters will operate from 10 locations around the UK.
Bristow, the American company who won the contract, say that the new fleet will be more advanced than the Sea King.
However, the MP for Berwick - Sir Alan Beith - told ITV News that the move will be sad for the community.
A private company is taking over the UK's helicopter search and rescue operations.
The Department for Transport announced the 10 year agreement with Bristow Group will start in 2015.
The £1.6 billion deal ends 70 years of search and rescue from the RAF and Royal Navy.
Under the new contract, 22 helicopters will operate from 10 locations around the UK, including RAF Boulmer in Northumberland.
The Department for Transport has said that under the new contract helicopters will be able to reach a larger area of the UK Search and Rescue region within an hour of take-off than is currently possible.
It added that, based on historic incident data, it is estimated there will be an overall improvement in flying times to incidents of around 20 percent (from 23 to 19 minutes).
Presently, approximately 70 percent of high and very high-risk areas within the UK SAR region are reachable by helicopter within 30 minutes. Under the new contract, approximately 85 percent of the same area would be reached within this time frame.
A flying instructor whose student died in a helicopter crash in North Yorkshire has been jailed for six months by a judge at Leeds Crown Court. Former Army Captain Ian King, aged 53, signed off Paul Spencer's training log just weeks before the tragedy.
He was found guilty of lying to the Civil Aviation Authority.
Mr Spencer, a wealthy businessman and his wife, Linda, from Brighouse, died when the helicopter he was piloting came down in Rudding Park at Harrogate in January 2008.
The court heard how Mr Spencer's flying experience fell below what was required for a licence. Judge Tom Bayliss QC told King his actions risked putting an inexperienced pilt at the controls of a helicopter.
A Middlesbrough man's among 19 people who've survived a helicopter ditching in the North Sea. 32 year old Jonathan Garcia was one of a team of oil workers being ferried from Aberdeen to a rig 86 miles north-west of Shetland. Rescue helicopter found all involved safe and well.