Pratt pilots object to wind turbines 

Pratt, Kan. – A group representing 20 individuals, calling themselves the Pratt Pilots Coalition, appeared before Pratt County Commissioners Monday to express their concern over some of the decisions recently made by the Federal Aviation Administration (FAA) relating to the location of some 68-wind turbine structures in Pratt County.

According to a letter sent to the FAA, all of the proposed structures are 427 feet in height above ground level and have a horizontal rotor diameter of 328 feet at a hub height of 262.5 feet. Forty-three of the proposed towers are within an eight statute mile radius of the Pratt Airport. Indeck Energy Services, Inc., 600 North Buffalo Grove Road, Suite 300, Buffalo Grove, IL 60089, submitted the proposal.

With this letter, the Pratt Pilots Coalition, a group of 20 pilots, aircraft owners, and aircraft operators who use the Pratt Regional Airport as a base of operation, are petitioning the FAA to review the “Determination of No Hazard”. They believe the wind towers to be built within an 8 statute mile radius of the airport, do present a hazard to VFR Air Navigation.

There are two types of flights, according to Mark McNay, who composed the letter for the group to the FAA. IFR flights are controlled by tower operations, while VFR are “visual flight rules”, which require no flight plan and because of weather, has limitations placed upon them. VFR flights could not land legally at Pratt Regional Airport under the present regulations if the wind farm were to be built, according to McNay.

According to the letter sent to the FAA, “If the 43 towers are constructed within 8-miles of the Pratt Regional Airport, VFR aircraft approaching from the west and northwest in marginal VFR weather conditions, will encounter obstacles to navigation. Those aircraft will be less that 273 feet above the wind turbine blades because they must remain below 700 feet when they are within 8-miles of the airport. To maintain the 500-foot clearance, pilots must attempt to maneuver between the high-density array of 43 towers under poor visibility, low cloud, and potentially high wind conditions, possibly at an altitude lower than the tower tops. Electronic navigation will be of little use, according to McNay, because a direct route to the traffic pattern will not be possible through the tower array.

“Itinerant pilots unfamiliar with the tower array will be at greatest risk, in marginal VFR visibilities. Those pilots may be entering the array before they visually detect it. The entire outer boundary of the array will not be visible from any given point during marginal VFR conditions because the proposed tower array covers approximately 16 square miles within the 8-mile radius,” according to the letter.

“The horizontal reach of the tower blades is 328 feet, therefore for obstacle clearance requirements, each structure occupies a 1,328 foot diameter horizontal no fly zone. The cumulative impact of 43 quarter mile no fly zones will be obvious impediments to air navigation for marginal VFR traffic approaching from the entire northwest quadrant.

“To avoid the array in marginal VFR conditions, many VFR pilots will attempt to remain north of the array and travel east until they intercept the final approach course for runway 17, 6-10 miles out from the airport. They will then approach the runway directly underneath the IFR final approach course, which obviously presents additional risk.

McNay said, “We also feel that the determination did not consider the impact of low level aircraft during full VFR operations. Agricultural spraying of crops by aircraft is common within the tower array boundary within 8-miles of the Pratt airport. The Agplane operator, a signatory to this petition, believes there will be significantly increased risk associated with his operations within the tower array. We consider that risk to represent an additional hazard to air navigation.”

Presently there are 11 communication towers southwest through southeast of the airport that lie underneath the 700-foot Class E airspace floor, and range from 255 to 499-feet in height, according to McNay.

“After adding the additional 43 Indeck towers, the only obstruction free approach for VFR aircraft, will be from the Northeast quadrant,” said McNay.

“There are approximately 11,500 flight operations at the Pratt airport each year. Seven thousand two hundred of those are local, 300 are air charter, 3,800 are itinerant, and 1,500 are military. Most are VFR and by necessity many occur under marginal VFR conditions in Class G airspace.”

In conclusion, the letter to the FAA stated the group believes that construction of the proposed wind towers within the 8-mile Class E airspace radius, will result in a significant increased risk to VFR flight operations, into and out of the Pratt Regional Airport and does indeed pose a practical hazard to navigation.