Originally Posted by
212man
Why it detached, I have no idea, but I very much doubt it had anything to do with a flailing TR drive shaft.
No no, im saying, the TRDS failed and caused the body to yaw. The yaw caused the blades to be rotating at a slower rate, which means, less lift. This a bit like dropping the collective, when it comes to disc loading.
So im not saying the TRDS vibration jolted the main transmission mounts off, im saying the helicopter ended up in a disaster because of the failure of the entire tail rotor and boom, and then that led to the loss of loading on the disc.
When the tail rotor fails, the helicopter spins. That sudden uncontrolled spin throws off the balance of the main rotor, which then can’t keep lifting properly, so it becomes ‘unloaded’ and stops holding the aircraft up. M
ast bumping did then occur, but it happened after the main event. It itself was not the main event.
In other words, the tail rotor stops working, and the whole helicopter starts spinning. Because there's nothing for the engine to push against anymore, the main rotor slows down in relaion to the air. And when it slows down, it cant make lift anymore and the helicopter falls.
That falling, is so quick and is effectively immediate, and would have resulted in the pilot pulling back on the cyclic, almost certainly sealing the fate of the rotor mast assembly.
EDIT: i should add, im quite focused on the images that helispotter also refferenced earlier on, where he showed the angle of the mast coming out on an angle from the transmission. Theres no goood foootage or photos yet close up, but it looks like a pretty good indicator of engine induced damage, not from hitting the water. Mast bumping usually bends or snaps the mast but theres no rules about what that must look like. typically with robbies its a completel crack and separation. The 206 mast is prety hefty.