It is a shame that technology is headed to China.
It was likely pilot error rather than engine problems. Most likely the helo entered a power settling situation, and there wasn’t sufficient altitude to recover. The only option was to nose over and look for a soft spot to crash.
The photos of the tail indicate a high vertical sink rate as would be expected in this situation.
I read the chopper encountered a vortex while trying to land and subsequently crashed.
I’ve seen three versions of why the helicopter went down.
1) It got too close to the walls of the compound.
2) Mechanical problem.
3) Hit by fire from the ground.
There is a theory out there that says that this helo got a little too close to the building and caused a ground effect problem resulting in loss of lift on the rotor blades.
Who knows which version is correct.