Topeka ? A helicopter crew from Westar Energy is flying around parts of the state this month to make sure power lines aren’t sagging too much.

The crew are measuring the height of about 400 miles of the utility’s transmission lines from Johnson County west to Salina and south to Wichita. They are checking to confirm that the lines meet federal requirements for clearance space.

The crew flew over Lawrence last Wednesday and Thursday, and is expected to continue moving west across the state, then south to Wichita.

The Topeka Capital-Journal reports Monday that Westar spokeswoman Gina Penzig says workers are trying to keep lines clear of any vegetation or other obstructions to prevent power outages.

Penzig says Westar the work is expected to be completed before the end of the year.