From May 13, the helicopters will fly above around Cessnock including Allandale, Branxton, Greta, Nulkaba and Pokolbin.

"We saw this year's bushfire danger period extended in parts of our network including the Upper Hunter, Muswellbrook and Singleton areas and we will begin our patrols in the areas of our network at greatest risk," Ausgrid chief operating officer Trevor Armstrong said.

"Safety is our highest priority and these patrols are a key part of our annual bushfire safety program to help identify and rectify any potential defects that might pose a bushfire risk.

"This year we have contracted two specialist helicopters to allow the patrols to be finished by the end of June, well before the start of the next bushfire season in September."

Two helicopters have been contracted to inspect areas of the electricity network in bushfire prone parts of the Hunter, Central Coast and Sydney.

The specialist crews will be using laser scanning equipment and taking high-resolution photographs to identify any hazards on our poles and wires and trees growing too close to powerlines.

"The patrols reduce safety risks for our own people, because by using a helicopter, we can identify potentially dangerous hazards from above without putting our workers at risk," Mr Armstrong said.

"Using the photographs means our own workers don't need to be placed in a position of having to examine damaged equipment up close."

Crews will be in the air from about 7.30am to 5.30pm, weather permitting, and property owners may want to consider securing livestock during the patrols.

"The helicopters fly between 15 and 35 kilometres per hour and have been modified to allow for the quietest possible operation but they may fly low at times, which can startle livestock in rural areas," Mr Armstrong said.

For more information including a flight schedule, visit ausgrid.com.au/bushfirepatrols.