Helicopters, unlike planes are not naturally aerodynamic objects.
That means that without their power source, they are not best placed for returning to Earth in a calm and orderly fashion.
For starters there are no wings to help it glide, and secondly it's a large big ball of heavy metal.
Despite all of this, helicopters do not plummet to the ground as you might assume and it's all thanks to a seriously clever piece of flying.
YouTuber SmarterEveryDay decided to become the guinea pig for this particular myth busting session and placed himself in a helicopter without an engine.
Instead, helicopter pilots are able to do use a technique called 'Autorotation' which essentially uses the air rushing upwards past the helicopter to then automatically spin the rotors and thus provide a small, but balancing amount of lift.
A very simple way of describing it is that you are simply switching the direction of air travel. When powered you're creating downward thrust, without power that air simply starts travelling upwards, and fast.
Pilots are then able to carefully flutter the rotor blades in such a way that they can maintain a slow and steady descent.
Of course it goes without saying that this is only really possible if you have your blades intact. But then gliding only really function on a plane if the wings are still attached.
1 Gamera II
2 Middle Georgia State College
3 University of Toronto, Atlas
4 Cal Poly, San Luis Obispo, 1989
5 Jim Douglas
6 An early prototype