[Morphling]

I wonder if you could just create some kind of roof over the rotors, thus negating the "attack".

[classicsnoot]

... but then someone else would invent balloons filled with mylar pieces that can saturate the area around the props.

[superuser2]

What exactly do you think is the point of helicopter rotors?

[Morphling]

Yeah, I'm not aerospace engineer, but couldn't you just put the roof like 10 cm above the rotors so it has enough air flow?

[ceejayoz]

To generate lift. It's most certainly not to shield the helicopter from attacks from above.

[krapp]

Not that.