I can tell a funny story.
I went out to Brazil a week after 9/11 happened, two weeks later when I was returning home I put my hand in my pocket to pull out my keys, change and hotel key (that's another story
) for the X Ray machine and discovered that I'd forgotten to pack my Swiss Army knife in my check in luggage.
I thought (It's very sentimentle to me) but had to throw it in the bowl along with change, keys, wallet etc.
To my amazment, I got to the other end of the X Ray to collect my belongings and no one even challenged me about the knife, I thanked him upstairs
, and continued on my jorney to Madrid (where I was to catch my connecting flight).
The exact same thing happened there as well, and I eventually landed in London with Knife intact.
I would have thought that any potential weapon on any flight would be banned.