The 93-metre span turbines near Tesco in Ramsey would be less than four kilometres from the Nene Valley Gliding Clubs base at Upwood, and would put pilots in mortal danger from turbulence, the clubs deputy chairman, Peter Valentine, told The Hunts Post on Tuesday. We fear that we would have dead pilots on our airfield, the retired aeronautical engineer said. We could not risk that, so it would mean closing the airfield. The problem, Mr Valentine explained, is the unknown cumulative effect of four turbines operating simultaneously. A single turbine slows the wind by 60-70 per cent, and the air tries to speed up to the speed of the wind that has not been affected by the blade, so its very turbulent and unpredictable, particularly for pilots of light aircraft, such as gliders, because you can suddenly lose lift on one side and fall into a spin. To recover from a spin takes a few hundred feet [of altitude], which you havent got when you are landing. Mr Valentine says the Civil Aviation Authorities guidance is that wind turbine should not be permitted within eight km of an airfield, and he is urging Huntingdonshire District Councils planners to refuse the application. Turbulence behind a single turbine extends for at least 20 times the diameter of the blades, he explains, probably compounded in a group of turbines, so a factor of 30 would be more appropriate, he calculates. And he believes there is another plan, yet to be submitted, for two more turbines even closer to the Upwood airfield. We have already had reports from more than one of our pilots about loss of lift and some instability as a result of the single turbine already placed very near to this new proposed development, and we believe that one landing in a field between that turbine and our runway was caused by the turbine rotor turbulence, fortunately without damage or personal injury. With a further four turbines this could well result in a serious accident, he has told planners. A further risk is that of a tow-line breaking before a glider is release by the tug aircraft, when the powered plane must turn right and the glider left potentially into the path of the turbine blades. We are probably the best club in this area and the only one with a significant proportion of young and trainee pilots. We are hoping to start a flying scholarship scheme, but we feel very threatened by these windmills. Mr Valentine was expecting to explain the aerodynamics and the gliding clubs fears to planning officers from HDC at the airfield last Thursday.