As a matter of interest, are there many more helicopter movements at Lasham? And, does this have an impct on the gliding activities?
Now I am not on my Ipad, a more thorough response.
They appear to be calling the LGS VHF frequency well in advance of any movements and then operating low level mainly from the south west, similar to the Squirrel maintenance movements did and all in accordance with Visual Flying Rules and under the Rules of the Air, a helicopter must give way to a glider.
Come on you Hatters! http://www.flickr.com/people/busterthebear/