Mon Power, a subsidiary of FirstEnergy Corp., is using two helicopters equipped with aerial saws to trim trees and maintain electrical clearances along eight difficult-to-access transmission line corridors in West Virginia. The work is scheduled to begin in mid-July and is expected to conclude by September.
Maintaining proper clearances around transmission lines and electrical equipment can help reduce the frequency and duration of tree-related power outages, especially those associated with severe weather.
"Taking this step to safeguard our high-voltage power lines is an important part of our vegetation management program and an effective way to reduce service interruptions for our customers," said Jim Myers, president of FirstEnergy's West Virginia operations.
The two helicopters trimming trees along the transmission lines are both MD 500s. One is white with a registration number of N53846, and the other is silver with a registration number of N369MP. The helicopters and saws are owned and operated by Aerial Solutions and will work only as weather conditions permit.
The aerial saws will trim trees along 187 miles of eight high-voltage transmission lines in the following locations:
- A 138-kV line in Brooke and Ohio counties that runs nearly nine miles from the Windsor Heights area to the Pennsylvania border
- A 138-kV line in Pendleton and Grant counties that runs 37 miles from Franklin to Petersburg
- A 500-kV line in Monongalia, Marion and Taylor counties that runs 29 miles from Pruntytown to Maidsville
- A 138-kV line in Monongalia, Marion and Taylor counties that runs 18 miles from Morgantown to Pruntytown
- A 138-kV line in Marion and Harrison counties that runs 19 miles from Fairmont to Clarksburg
- A 138-kV line in Taylor and Preston counties that runs 30 miles from Pruntytown to Albright
- A 138-kV line in Braxton and Nicholas counties that runs 23 miles from Sutton to Powell Mountain
- A 138-kV line in Upshur and Randolph counties that runs 22 miles from Buckhannon to Elkins
Suspended on an adjustable 90-ft boom beneath a helicopter and equipped with multiple 24-in. rotary blades, the aerial saw is typically deployed along transmission lines in areas that are environmentally sensitive or inaccessible to bucket trucks and other vehicles. This fast, safe and efficient method of trimming typically covers more area in a day than a ground crew might complete in a week. The saw also eliminates the risk of injury to workers using bucket trucks or climbing trees to cut limbs near high-voltage equipment.
The saw cleanly cuts tree limbs 8 to 10 in. in diameter, which fall straight to the ground propelled by air blasts from the helicopter rotors. Ground crews move limbs that have fallen onto roadways, yards, agricultural fields or in streams into adjacent wooded areas. The ground crew will also flag and stop motorists along roads if the saw is working nearby.
The helicopter flies above and alongside transmission lines and may circle around to perform additional trimming. The pilot communicates with local airport personnel whenever the helicopter is operating within their air space.
Mon Power will clear vegetation along approximately 5,700 miles of distribution and transmission power lines in its West Virginia service area this year as part of its $70 million vegetation management program.
Trimming trees around power lines is critical to providing reliable electric service for Mon Power customers. In the company's 34-county service territory, total customer outage minutes, including during major storm events, have dropped by more than 40% since the first full year of its existing tree-trimming program in 2015.