Why Do Helicopters Struggle To Hover When There's No Wind ?

[Canary42]

Why do Helicopters struggle to hover when there's no wind ?

"According to the Coastguard it was a difficult operation, as even though weather conditions were good the helicopter struggled to hover with no wind" quote from :-

http://www.bbc.co.uk/news/uk-northern-ireland-44349785

[Buenchico]

The aerodynamics associated with helicopters isn't exactly the easiest subject to understand! Helicopters function best though when they're given assistance from 'translation lift'. See here:
http://okigihan.blogspot.com/2017/06/helicopter-aerodynamics-of-flight.html

[KARL]

The whole point of the helicopter concept is that it creates its own lift with the motorised rotor, not needing any wind to do so, unlike a gyrocopter which needs a distinct net headwind (in motorised versions this is provided by a conventional propeller creating forward motion) to remain aloft. I don't understand/accept the statement at face value. In case of a wind the rotor is tipped/inclined to counter the wind in order to hover over a fixed location, otherwise the rotor turns horizontally with the pitch set to counter the aircraft's weight.

[Canary42]

Thanks Chris for that link - it makes fascinating reading (even if I didn't understand some bits) and raises a number of features I wouldn't give a thought to normally, but are obvious when pointed out. One example being the lack of lift from the blade which is moving in the opposite direction to that of the flight if the helicopter is moving too fast - the whole dynamic is very complex and quite scary in a way.

Altogether a very interesting article - I'm quite glad I asked the question. And small wonder the Coastguard "simplified" it with a bare statement.

[EDDIE51]

It looks like the Helicopter was very near the cliff. So the Hover had to be very precise & accurate to avoid the roter tip touching the cliff edge.
I think the coast guard was intending to say that 'even with no wind' the Helicopter struggled to hover. With wind it would not just have been a struggle it would have been impossible.

[jno]

I don't think so, Eddie.

He said the weather conditions and lack of wind were challenging for the pilot

Sounds as if they actively need wind.

[Theland]

One crashed in Osama Bin Ladens compound because it was walled in to static air.