Never even crossed my mind regarding the airside pass, but it could be a problem. I thought my RAF id got me access anywhere - LOL before the anti-RAF brigade start again.
I agree the liability issue would be a problem but I was hoping that I would/could work under close supervision as I would only be doing a job which would have been tasked to a qualified engineer.
We do the same with work experience guys ready to leave school and thought the same could apply for me.