[livinginfear]

It's a shame that someone so dedicated to their passions had to die young.

Did he spend any time modeling the physics of a helicopter control system? It would have to be of the most complex control systems to model. You don't just build a helicopter. Maybe he should have begun by building a scaled-down version instead. Maybe he did all of this due diligence, and just overlooked some unfortunate minor detail. Some of the comments here are blaming materials failure.

[system2]

He made the helicopter from sheet metal. I don't think he really understood the high speed rotation's effects on them. A few grams of imbalance can totally destroy the rotors. Which probably what happened in this video.