Could the turbine-aircraft collision have been avoided?

UPDATE: Since this essay was published, additional information from the NTSB investigation has been released. It is now confirmed that the FAA aviation safety light on the turbine that was hit (tower #14) was not functioning at the time of the accident and had been inoperative for an undefined period. According to NextEra records, there is no information showing that maintenance was conducted or performed on the FAA lighting system since 2010 and the accident.records indicate the light had not been inspected. The accident report (attached to this page) states that the  pilot may have observed the lights from the surrounding wind turbines, and "perceived a break in the light string between the wind turbines as an obstacle-free zone."

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Last week,  we received word of a tragic accident in South Dakota where a Piper PA-32R-300 airplane was destroyed after colliding with the blade of a wind turbine. The incident, which occurred just eleven miles south of Highmore, South Dakota, took the lives of the pilot and three passengers. The National Transportation Safety Board (NTSB) released its preliminary report on the accident where it stated:

"The wreckage of the airplane was scattered in a radius surrounding the base of a wind turbine. The airplane was fragmented. One turbine blade exhibited impact damage and was broken into several large pieces, several of which remained attached to the turbine nacelle. The remaining two turbine blades exhibited impact damage."

The wind energy facility, known as the South Dakota Wind Energy Center, was erected in 2003 by NextEra and consists of 27 GE-1.5 megawatt turbines (40.5 megawatts) each standing 330 feet.

The NTSB is investigating why the pilot was flying his plane at an elevation low enough to hit the blades, but weather may have been a factor. Heavy fog, wind gusts and rain were reported in the area.

We look forward to getting more details on the crash, but Windaction.org has identified a disturbing fact that likely will not be reported in the news.

According to the SkyVector Aeronautical Charts, which includes the official aviation sectional charts for the entire USA, the wind turbines involved in the accident were never posted on the navigation charts! (See the image on this page)

Did fog obscure the turbines? Is it possible the pilot, who was flying under visual flight rules (VFR), had no idea he entered a field of wind turbines? If he was relying on aviation maps and visual cues, a turbine blade could have smacked the plane out of the air before its passengers even realized the threat.

We may never know exactly what happened. But what we do know is that roughly 40,000 utility-scale wind turbines are operating in the United States today and every project is required to be shown on the aviation charts and to have some form of FAA lighting that is operational. How many other turbines are missing from the sky maps? Are there other accidents waiting to happen?

Notes about the image:

Click on the image to see a larger visual of the aviation chart showing the area of the accident. Notice there are no icons indicating wind turbines as you can see near Miller, SD along the top of the map. The pilot was headed to Highmore, SD airport, just 11 miles north of the turbines.The image is a composite of screen captures from Google Maps and the SkyVector charts.

Editor's note (added March 2, 2017) - The final report of the NTSB has been released and can be downloaded from this page or viewed at this link: NTSB Accident ID CEN14FA224