What are the possiblities of aircraft towbar cracks at flange?

Question

cracks has appeared at half the flange at tug side

Answer 1

I have seen this before once.    Our pushback driver was driving forward with the towbar attached at the front of the pushback.  He let the towbar get away from him, and he ended up hitting it with the tug.  Basically he jacknifed it.  

Hope this helps.

Answer 2

the plane has been sabotage or its malfunctioning due to low mainteinance

Answer 3

Tow bars fail just as any other mechanical device does.  And yes, they will crack out at the flange.