I am now 17 and I spent AGES trying to find a work experience placement in aviation when I was in year 10. There were lots of empty promises made, lots of guaranteed placements which never materialised! The key is just to keep nagging all the companies you can - it worked for me. In fact, the last website I stumbled across (by mistake!) was that of the company I got a two-week placement with at Luton, and it was great!
If you want any more info, email me:
[email protected] and I will see whether I can help you - I have a couple of contacts here and there!
Good luck!
Leon