The Chief engineer at an airplane factory called all his men together. Right he says, every time the plane does a barrel roll the wings break off we have tried everything has anyone further ideas we have got to fix this.
There is a long pause and no one answers so he say come someone please, a hand goes up at the back and a man steps forward in old coveralls, the Chief engineer asks can you fix this, the man says he needs a drill with a one inch bit and a step ladder, well we have tried everything the chief says so I will let you try, so the man proceeds to drill a row of holes across each wing where they keep breaking. The test pilot takes the plane up and does every thing he can but the wings stay on, when he lands the plane the chief engineer ask the man which department he is from, he replies I am the janitor and one thing I have noticed in my work is the toilet paper never tears along the perforations.