I think it's Royal Marines now. If you can get a copy of the RAF Helicopter Landing Site booklet, it will have a phone number; listed in some places as A/G 130.2 but no phone number.
If the gliding unit was an Air Cadet one, they usually only operate at weekends and they're not too active at the moment - see the thread about Air Cadets grounded.
Having said all that, I've found an old copy of the HLS directory which gives a phone number as 01271 857220, but this may be the SAR unit which may not exist any more.
Last edited by chevvron; 22nd Sep 2015 at 11:17.