Pilot’s Nightmare: Wind Turbines Present Clear & Present Danger For Light Aircraft

All power generation comes with risk. However, those risks are traded off against the immeasurable societal benefits provided by reliable and affordable electricity.

Where the power source is wholly weather dependent – and the industry that profits from it wholly dependent upon massive and endless subsidies and, therefore, wholly unsustainable – there is nothing to trade off worth the lives of those who take to the skies, particularly for a living.

In short, wind power creates a whole raft of wholly unnecessary risks to life and limb, not least for Ag-pilots. Here’s another great piece from the Daily Caller’s Andrew Follett.

Wind Turbines Create Big Problems For Small Planes
Daily Caller
Andrew Follett
21 April 2017

The proliferation of unmarked wind turbines in recent years poses a huge risk to thousands of pilots flying over farms every day, according to a top lobbyist for crop-dusters.

Crashing into wind turbines has killed at least four crop-duster pilots in the U.S. since 2003, including one in Minnesota last August. The spinning blades of the turbines poses several risks for pilots, the problem will likely get worse as wind power continues to expand, fueled by government subsidies.

“You’ve got two issues with wind turbines,” Dominique Youakim, president of the National Agricultural Aviation Association, told The Daily Caller News Foundation. “One is the field in which the wind turbine is located. If you have to work a field and a turbine is adjacent to it you can’t fly around it. You can’t pull up because you’ve got a 200 foot tower in the middle of the field.”

Wind turbines are difficult to see and nearly impossible to avoid once an aircraft gets too close. Their pale, narrow turbine blades blend in with the sky or disappear in sun’s glare. Turbines are rarely adequately marked to warn pilots.

“You can also get vertigo from the movement of the turbine blades, so you’ve got to spot it, but not let your eyes get drawn to it,” Youakim said. “Kind of like your windshield wiper on your car, you can’t focus on those or you’ll end up wrecking. It’s an added distraction.”

“The vortices and the turbulence that the wind turbines generate can be tremendous as well,” said Youakim. “When we’re doing an application we’re typically only 16 feet in the air at the highest level. Your typical wind turbine is 150 feet tall and will alter the airflow around the turbine when it is moving.”

One pilot named Van Lucas flew missions over Iraq and Afghanistan in a fighter jet before working as a crop-duster in Iowa. Even he couldn’t avoid crashing once he got too close to a wind turbine and its web of anchoring guy wires.

“I just prayed and pulled. Pulled back on the stick and got out of there quick as I could, hoping I didn’t hit it,” Lucas told The New York Times in October 2014. “By the time I pulled up, the guy wires were right underneath the airplane.”

“Agriculture pilots often fly highly inefficient flight paths to avoid wind turbines spread across Midwest corn fields. They fly low, spray their pesticides all while trying to avoid towering wind turbines.”

“Pretend a corn field is like a football field as a lot of them are long and narrow,” Youakim said. “To spray efficiently you’d fly the length of the football field to get it done efficiently. Now let’s say they put a wind turbine at the end of it. You can’t go the length of the field anymore so you have to go across the width.”

“Instead of taking 15 to 20 minutes to do a field you’re doing 40 to 50 minutes,” Youakim said. “That costs a lot more money at the end of the day. If you’re working inside a windmill farm there’s no rhyme or reasons to how they’re laid out. It’s not like they’re lined up in a row, they’re randomly placed in the middle of the field.”

Youakim said wind power companies could reduce the risk of aerial collision by placing markers or lights on the blades of wind turbines. Youakim also said unmarked meteorological towers pose a similar threat.

“Windmills are typically marked at the top of the tower,” said Youakim, “At the top of the pedestal in the center there’s a marking, but it’s not on the blades and they go above the high point by about 75 feet in some cases. If you compare that to tower, they have to be marked at the highest point according to the FAA. If the blades aren’t marked that can be a serious safety risk if they’re flying at night.”

The National Transportation Safety Board launched a special investigation in 2014, which found unmarked towers were a “critical hazard” to low-flying agricultural planes. The board called on the Federal Aviation Administration (FAA) to require better lighting and brightly-colored markings, but little has changed.

The wind energy industry has made efforts to improve safety for crop dusters and other workers in close proximity to turbines. Industry representatives say they’ve worked to raise awareness about planes crashing into turbine towers, which they point out is extremely rare.

“It’s important to know aircraft collisions with wind power development MET towers are exceedingly rare,” David Ward, a spokesperson for the American Wind Energy Association (AWEA), told TheDCNF. “There are only four known occurrences where small, low-flying aircraft collided with wind power development MET towers.”

“The wind energy industry has supported efforts to improve the visibility of the towers as we have been working for several years to improve pilot safety and the safety of our workers,” Ward said. “AWEA has engaged with our members, trade associations representing pilots, legislators, and regulators over the last several years to improve awareness of the issues faced by both pilots and the wind energy industry and try to find consensus on ways to improve pilot safety.”
Daily Caller

Wind Turbine claims 4 in South Dakota.

4 thoughts on “Pilot’s Nightmare: Wind Turbines Present Clear & Present Danger For Light Aircraft

  1. At the present time the UK CAA has a policy [ CAP 764] providing guidance on wind turbines including avoidance of turbulence. To avoid down wind turbulence pilots are advised to remain at least 16 rotor diameters downwind of turbines. With a RD of 140 metres this would provide for a possible impact zone out to 2240 metres. The wind industry has its own rules of thumb about wake turbulence impacts one of which is expressed as the 5R 8R rule, ie impacts go out to 5 RD’s abreast and 8 RDs downwind. They are not inclined to even respect this rule, and regularly squeeze turbines into more confined spaces and downplay the effects of turbulence, those effects being very important in the production of noise emissions.

  2. The University of Liverpool in the UK has been conducting research into wake turbulence from wind turbines.


    The UK Civil Aviation Authority also has a section covering wind farms.

    Click to access CAP764%20Issue6%20FINAL%20Feb.pdf

    One point of interest is the section on wake turbulence.



    2.51 Turbulence is caused by the wake of the turbine which extends down-wind behind the blades and the tower, from a near to a far field. The dissipation of the wake and the reduction of its intensity depend on the convection, the turbulence diffusion, the topography (obstacles, terrain etc.) and the atmospheric conditions.

    …end quote.

    There are some good diagrams illustrating this point too.

    In addition to this, there are some interesting suggestions for the location of wind turbines near an aerodrome. See below. I am pretty sure that the Portland Wind Energy Facility in Victoria is located far closer to Portland Airport than the 17 klm setback suggested in section 3.


    Aerodromes. Whilst not definitive, it should be anticipated that any wind turbine development within the following criteria32 might have an impact upon civil aerodrome33 – related operations:

    1. Unless otherwise specified by the aerodrome or indicated on the aerodrome’s published wind turbine consultation map, within 30 km of an aerodrome with a surveillance radar facility. The distance can be far greater than 30 km depending upon a number of factors including the type and coverage of the radar and the particular operation at the aerodrome;

    2. Within airspace coincidental with any published Instrument Flight Procedure (IFP) to take into account the aerodrome’s requirement to protect its IFPs;

    3. Within 17 km of a non-radar equipped licensed34 aerodrome with a runway of 1100 m or more;

    4. Within 5 km of a non-radar equipped licensed aerodrome with a runway of less than 1100 m;

    5. Within 4 km of a non-radar equipped unlicensed aerodrome with a runway of more than 800 m;

    6. Within 3 km of a non-radar equipped unlicensed aerodrome with a runway of less than 800 m.

    …end quote.

    I would have thought with the evidence gathered so far that a greater setback should apply to light aircraft operations?

    However, it would appear that for Amsterdam Schiphol airport, the normal rules for locating wind turbines in close proximity to an airport do not apply. I think I shall avoid flying into Schiphol airport from now on if the YouTube clip below is anything to go by!

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