There is a gliding club just to the left of the image. Fortunately, as I can see the site from my house, I know when I can fly overhead. Also this flight was during the week and they only operate outside of working hours.
Here is a picture of the gliding site(bottom right):
@R Supwoods: Yes, it seems I must be your neighbour! I live down Malthouse Lane. Quite a nice area but can be a bit quiet for my liking