Bell Helicopter Video
I saw some of the 1st prototypes and Can't understand why He lost interest in his 1st concept with props at the end of the Blades.Seems it had a c.g. problem and never had any control surfaces for axis? Just a counter blade to offset torque? Wing had no Dyhedral and was not rigid.If he had added some weight to it's center it would have been much more controlable At that point it lifted Fine!C.G. is very important to controlling a Heli.