Wind Turbine Construction at Tehachapi, CA – CalPilots Response

The California Pilots Association response – Public Comment to Draft Environmental Impact Report (EIR) SCH# 2010031067 Wind Turbine Construction at Tehachapi, CA (ClearVista Wind Project).

December 14, 2010

Kern County
Planning and Community Development Department
2700 “M” Street, Suite 100
Bakersfield, CA 93301

Re: Public Comment to Draft Environmental Impact Report (EIR) SCH# 2010031067 Wind Turbine Construction at Tehachapi, CA (ClearVista Wind Project)

Dear Ms. Oviatt:

Mountain Valley Airport (FAA LID: L94) is an airport used for glider operations and training located in Tehachapi, California. The airport was established for its close proximity to various advantageous lift effects for soaring where the Sierra Nevada Mountains, Tehachapi Mountains and the Mojave Desert meet. The site is known as the “Gateway to the Sierras” and numerous world-record glider flights have originated from Mountain Valley Airport. The Skylark North Glider School performs glider flight training for civilians as well as for the US Air Force Test Pilot School (from Edwards AFB), the National Test Pilot School (from the

Mojave Air & Space Port), NASA and others. Due to the ongoing training contract with the US Air Force Test Pilot School, probably most or nearly all NASA Space Shuttle pilots who came from the Air Force have received glider training at Mountain Valley Airport.

The California Pilots Association is concerned about the proposed construction of 14 wind turbines comprising the ClearVista Energy Wind Project within close proximity to Mountain Valley Airport. The Draft EIR correctly notes that the proposed structures, situated northeast of the airport, result in a “significant and unavoidable” obstruction to air navigation so long as their design results in penetration of the FAR Part 77 conical surface.

We support the FAA’s inquiry into the appropriate safety issues and expect that project approval be denied until such time as the proposed turbines meet the FAR part 77 obstruction standards and do not pose any adverse effects upon aeronautical operations or air navigation.

We ask also that you consider the significant aeronautical safety risks posed by these large turbines due to the unique nature of Mountain Valley Airport as one of the busiest sites of glider operations and training in Southern California. The Draft EIR reads in pertinent part:

Impact 4.11-3: Result in a change in air traffic that result[sic] in substantial safety risks.

This impact is further exacerbated because the Mountain Valley Airport serves glider planes, which have a more limited maneuverability and therefore are at increased risk due to obstructions.

The FAA Airport Master Record for Mountain Valley Airport shows 50,000 total operations for the 12 months ending on May 31, 2010. Of those, 43,000 operations are attributable to local or itinerant glider aircraft. Gliders return to Mountain Valley airport predominantly from the north and east after cross-country flights of up to 400 or 500 miles.

Because of the great distances flown the aircraft often return to the airport late in the day when there is less available lift. While returning glider pilots calculate carefully the minimum altitudes required to safely clear the mountain ridges to the north of Tehachapi, the imposition of obstacles nearly 500 feet tall directly in the path of returning gliders and within 1.5 nautical miles of the runway threshold creates an extreme hazard because gliders by their design cannot simply “add power” to climb over these obstacles. Add to that equation the imponderables of headwinds, sinking air, or other meteorological factors and it becomes apparent that the wind turbines at issue significantly narrow the margin for error for landing at that airport.

Kindly direct responses to this letter to my e-mail address or direct line.


Christopher P. Mannion
VP-Region 5 – California Pilots Association

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