Accidents involving wind turbines and airplanes are few and far between, according to the National Transportation Safety Board’s online database.
The crash of a small Piper aircraft destroyed in an April 27 accident when it crossed paths with the blade of a wind turbine near Highmore is only the second of its kind reported in the database. Last month’s accident is under investigation by the NTSB, a federal group that investigates all aircraft incidents.
According to NTSB investigator Jennifer Rodi, a complete investigation will take eight to 10 months, but a preliminary accident report has been filed. That report confirmed that Gettysburg pilot Donald “DJ” Fischer intended to land at the Highmore airport, which is about 11 miles north of the crash site, where a 27-turbine wind farm is operated by NextEra Energy.
Turbines on this particular wind farm are 10 miles south of Highmore. Most of them are west of state Highway 47 and four are in an offset row east of the highway. Those to the west include a short row of five turbines followed by a second row of five a little farther south. Another 13 turbines are configured in a row that follows a line to the southwest.
Steve Stengel, spokesman for NextEra, confirmed accidents like this are unique.
“We think that statistics would bear this out,” he said. “Wind turbines are very, very safe. All these projects that are built – whether in South Dakota, North Dakota, California or Pennsylvania – they all go through a review and approval process to make sure they are safe and appropriate in the area they are placed in.”
A search of accident reports on the NTSB online database found one other accident that involved an aircraft colliding with a wind turbine. That incident took place in Palm Springs, Calif., in 2001. According to the NTSB final report, that accident occurred following an in-flight breakage of two pieces from the plane, causing the pilot to lose control and strike a wind turbine. The cause of the accident was attributed to the aircraft not being assembled properly.
In the case of the Highmore accident, Rodi said investigators will be looking into why the aircraft was flying so low. Stengel said the wind turbines from ground to tip stand 300 feet tall.
Saying where an aircraft should be gets complicated as Federal Aviation Administration has extensive regulations which take into consideration several variables, including visibility, distance from cloud layers and classifications of air space.
When it comes to wind turbine safety, the FAA requires white warning lights to be active during the day and red lights at night. According to the Advisory Circular issued by the FAA, the lights are intended to aid pilots in identifying and avoiding obstacles. The lights aren’t required on every turbine, but must be placed on the turbines on the outside edge of a wind farm development. Flashing lights shouldn’t be more than a half mile apart.
Stengel said wind turbines in the Highmore area are monitored from a number of locations.
“If there’s something that’s not right with the machine, we might get some sort of warning or notification,” Stengel said. “Many times, it requires a technician to go and climb the machine.”
In this case, Stengel said, the local technician is also a volunteer fireman and the last known GPS location of the plane coincided with the wind farm.
“He went out with the fire crew,” Stengel said. “That’s how the plane was located. It was in his capacity as a fireman that we were made aware there was a plane on site.”
NextEra operates 101 wind projects in 19 states across the United States and Canada. Stengel said future wind energy development is a key part of the company’s strategy.
“We’re building a number of projects,” Stengel said. “We still feel very positive about wind energy. Not only about environmental, but economic benefits.”