The site was located within a sensitive area for Blackpool internal airport’s air traffic control system. This operated single scan radar and detected objects at low levels and was able to pick up the height of waves 23 miles distant during bad weather. The airport stated that the turbine would appear as a fixed object on the radar which would necessitate a controller advising aircraft to take avoiding action. A second airfield at Wharton which was used by microlights was also likely to be affected despite benefiting from a more sophisticated radar system which could allow some data returns to be eliminated.
The combination of increased radar clutter when coupled with microlight flights increased the risk that air traffic controllers would misinterpret the data. Filtering out the impact of the turbine on radar returns was also likely to lead to the removal of some microlight flights thereby increasing the risk to other aircraft. Aircraft approaching the runway at Blackpool would have to take a five nautical mile diversion which would increase fuel usage and increase the difficulty of aligning the planes with the centreline. Although work was underway to develop a radar system which could effectively filter out the impact of wind turbines this had not been fully tested and it was inappropriate to impose a ‘Grampian’ condition preventing the erection of the turbine until an adequate scheme of mitigating the impact on air safety had been produced.
In so concluding the inspector accepted that the wind turbine would reduce the energy costs of the business which employed 20 full-time staff and which supplied local and national markets with fresh salad crops. It would reduce the need for the company to use electricity from the national grid thereby minimising the use of fossil fuels. It would also have an acceptable impact on the landscape. But in addition to undermining air safety it was be likely to lead to unacceptable noise disturbance to residents in dwellings the nearest of which was approximately 250 metres distant.
Inspector Zoë Hill; Hearing