Yes, I remember this as well when part of the RAF Gliding and Soaring team taking part in the Nationals at Lasham mega moons ago. Possibly 1964 or around then. The site was on the opposite side of the road to the airfield proper and where the RAF crowd would set up camp in an assortment of tents and caravans, complete with a field kitchen. Wonder what happened to all that hardware! 🙂

Possibly ended up here in the post closure section (note second paragraph)

http://en.wikipedia.org/wiki/Meon_Valley_Railway

and this thread as well…

http://forum.keypublishing.co.uk/showthread.php?t=79327&highlight=lasham+dump&page=2 post #37