EAU CLAIRE, Wis. (WKBT/AP) -

Northwestern Wisconsin residents might soon notice a helicopter cruising over their neighborhoods.

Xcel Energy plans to start a six-day aerial inspection its transmission lines on April 21. Helicopter crews will look for defects, loose fittings and other potential problems that could cause outages.

The patrols will take place during the day. The helicopter will fly within 50 feet of the lines at speeds of up to 45 miles per hour. The helicopter will hover if crews need to take a closer look at a potential problem.

"These inspections give us a 'birds-eye' view of the transmission system and allow us to fix potential problems before they occur," Xcel Energy's supervisor of Field Operations Ralph Melgard said in a statement. "The patrols and the associated maintenance are important to continue to provide reliable electric service to our customers."