Yes, that's a giant saw dangling from a helicopter. Ask Eversource

Don't be alarmed if you are in western Massachusetts and see a tree-trimming saw dangling from a helicopter.

Eversource on Tuesday is embarking on its campaign to maintain clearance near its transmission lines, an effort that will involve suspending a 10-bladed saw below a Hughes 369D helicopter to trim tree limbs along what the utility calls "the superhighway of the power grid."

The approach enables crews to access hard-to-reach areas, allows corridors to be cleaned up more quickly than with traditional, ground-based crews, and reduces the risk of injuries associated with using saws when climbing trees to trim them.

According to Eversource spokeswoman Priscilla Ress, the utility has been using the helicopter-based approach to trim trees from the air for a few years in Massachusetts, Connecticut and New Hampshire.

The chopper flies about 200 feet above the ground, at about 25 miles per hour, and the saw hangs down about 90 to 120 feet below the helicopter. A chopper-based crew can complete work along both sides of a one- to three-mile corridor per day.

The work is scheduled to run through April 6, with flights between 7:30 a.m. and 5 p.m. in the towns of Hampden, Wilbraham, Ludlow, Agawam, East Longmeadow, Longmeadow, South Hadley, Holyoke, Westfield, West Springfield and Chicopee.