THE gliding club at Upwood is well established and has enjoyed safe use of the air space locally for 40 years. The erection of wind turbines at distances of between 1,500m 2,000m from the centre of the runway will compromise that safety and the existence of the club.

While it is accepted that there a positive presumption in favour of renewable energy technologies, it is also the case that the latest Government guidance requires that local authorities place great weight on the impacts such technologies will have.

The proposed turbines will have a very serious impact on the safety of the club and its continued operation - impacts that would be unacceptable for reasons of basic aviation safety and which, we would suggest, are matters of serious public interest.

The only way to make these impacts acceptable would be for the turbines to be sited at a safe distance from the airfield.

The essential problem in the case of gliders centres on their specific vulnerabilty. The large turbines proposed will give rise to disturbed air flow for in excess of 1,500m away. Should this turbulence reach a glider take-off runway anywhere along its length the launch of a glider could become unsafe, with the risk of loss of lift and a possible spin into the ground as spin recovery from that low an altitude is usually unsuccessful and will result in the pilot's death

Should a glider encounter the unstable air while in a turn during the later part of the landing circuit, the lower wing of the aircraft [the first one in the turbulence] would lose lift suddenly and that lower wing could simply stall and plunge the aircraft into a spin, again with potentially fatal consequences.

During operations at Upwood, light aircraft are sometimes used to tow gliders into the air in addition to the winches. When taking off towards Ramsey it is necessary for the tug and glider combination to turn away from Ramsey town in order to comply with the law in respect of safe height over buildings. A failure of the tug aircraft's engine or a break in the tow-line at that phase of flight could well see the glider having to turn within the turbulence area at low altitude with results alluded to above.

Turbines represent tall vertical obstructions which pose a real danger to gliders if they should suffer a loss of thermal lift. The closer a turbine is to a landing area the greater this risk becomes as gliders are more likely to be at similar levels to the standing turbines.

For this reason and those set out above it would seem prudent to establish a zone of around 4km from the nearest turbine to the airfield boundary to take account of all risks of turbulence upsetting aerodynamic lift necessary for the safe flight of a glider, especially when less experienced solo pilots are flying.

The more turbines positioned together as a multi-turbine development the greater and less predictable down-wind turbulence and therefore the greater the separation from the airfield boundary to ensure flight safety.

MICHAEL MUIR

Chairman, Nene Valley Gliding Club

Upwood