Please excuse my lack of knowledge here , but come somebody explain what that was all about ? I presume that it was being tested ? and the rear pylon fell off on purpose . Please do tell as i feel a complete biff
It appears to be on a test rig for either ground resonance testing or blade load testing. You can see a vertical marker at the rear of the fuselage possibly to indicate lateral oscillations. Not sure if they planned on it being destructive testing though. It actually took a surprisingly long amount of time before it completely broke up considering the state the blades were in half way through the clip.
You want to have a look at the comments on that site. It turns into a reet old USA v The world.