http://www.youtube.com/watch?v=5TPfHpJ7Wkc

I learned to fly fixed wing slope soaring. I was kind of thinking "this can't work with a heli, can it?"

Many years ago there was a group of heli flyers in Wasghington state that used to slop soar their Kyosho Concept helis, I believe on of their names was Derrick Dittes. He was also a very good sailplane and R/C heli pilot.

it's called autorotation when a heli does it, the bigger the heli the better, you should go up with the wind if your, blade area+ friction X weight =is not too much, heli's aren't as effective as planes, they take more power to fly so it's not going to be easy but autorotation is using speed to spin the blades where matey is using the wind blowing up for lift than trading some lift to spin the blades, the small 450 makes life hard as there is not much energy in the blades cos they're light, you don't have time to adjust the pitch to get the right balance of lift the head speed,

Just to clarify, slope soaring is akin to an autorotation as one is not using power. But in an autorotation, one must land, as he only has a limited amount of energy left in his rotor after lose of power, so he descends and land.

As in this video:

http://www.youtube.com/user/PreddyGS.../0/I-Pn4KNf-RU

Slope soaring is akin, in that does not have a power source inside the heli (or airplane for that matter), but one is using the energy in the slope's upward wind to maintain rotor speed, rather then the descending speed of the heli (as in an autorotation) to maintain the rotor speed.

In both cases the heli is effectively in an "autorotative state" but different energy sources are being used to maintain flight and control.

it's the same source, it's the wind thats moving in stead of the heli moving against the air, your spilting hairs, the heli is droping against the wind but as the wind is moving up the heli seems to lift, it falling compered to the air, it's like a small plane flying in to a very strong wind, the plan is flying so it's moving forward compered to the wind but compered to the ground it could be going backwards,