Man's attempts at flight have tried to imitate that of birds. As with bird flight, the aim was to have complete freedom in air using direct lift, i.e. to take-off and land vertically, fly up and around, straight and level and hover under powered flight. Initially this proved to be difficult.

'The conception of flight then became reversed because instead of rising into the air and then going forward, we were concerned wholly with going forward at a sufficient speed to maintain ourselves in the air.
This diversion, and it was a diversion, gave us the simpler
solution of the airplane, which although it has made enormous strides, still has and always will have the shortcoming of being critically dependent on speed.' - Dr. J.A.J.Bennett

The first production helicopter can be argued to be one that was the easiest to produce, with the least amount of complications and the easiest to fly hence the Flettner helicopter. Physicists call it the Path of Least Resistance. The V-22 Osprey has been dogged by all sorts of proplems. It has a lot of potential if it wasn't restricted by technology. Health and safety means redundant parts. Heavy transmission and other bits mean low payload. In addition, the rotor is a dog as far as certain flight phases are concerned e.g. Vortex ring state. With continued research I think the V-22 can be a winner, however lets not give up on the Single main and tail.

What I don't understand is why the XV-15 was scrapped. It's rotor was better in a number of ways.

In what ways do you think the XV-15 rotor was better than the V-22?