in fact it crashed because it was hovering over the (walled) compound, and those walls were modifying the air flow and causing a vortex ring state. Most helicop

in fact it crashed because it was hovering over the (walled) compound, and those walls were modifying the air flow and causing a vortex ring state. Most helicopters would have suffered the same fate. https://en.wikipedia.org/wiki/Vortex_ring_state https://en.wikipedia.org/wiki/Vortex_ring_state