The V-22 can carry the same troop load as the CH
-46E, and it can carry that load at a higher altitude, at a greater speed, and for a greater distance. Since that's the platform the V-22 is supposed to replace, sounds like an upgrade in capability.
And a joint venture between Bell and Agusta is looking to develop this technology for the civilian market.
As for the last accident - which was 3-4 years ago - that was a result of pilot error and insufficient flight test. In other words, the pilot exceeded the then-certified flight envelope, and due to funding/schedule delays in the flight test program, did not have knowledge of suitable recovery techniques.
Rotor disk stall is a known phenomenon, and the flight envelope was restricted to avoid that possibility. Limit your max descent rate, you eliminate the possibility of generating a ring vortex. The pilot's descent rate in the exercise exceeded the allowable limits. His recovery techniques - namely, increase forward speed to escape his own vortex - would have worked had he been flying a helicopter. But he wasn't.
Now, in fairness to him, various funding cuts and subsequent restructuring of the flight test plan did not permit sufficient testing into this particular area of the flight envelope. [Stupid, when you consider this
is the type of mission it will be executing.]
The test program that was undertaken following this accident determined (a) the no-kidding, absolute maximum descent rate; and (b) the recovery technique. Namely, tilt your nacelles forward 5-8 degrees to throw the vortex off your rotor. There was an article in Proceedings
magazine a couple of months ago from the V-22 chief test pilot that explains this a little better than I can.
This accident is, to my knowledge, the only one whose cause can be directly - and solely - traced to aerodynamics. In the majority of the other incidents, poor manufacturing/quality control led to the failure of various mechanical components, leading directly to a crash. These have since been re-designed. Software was also a contributing factor in at least one incident.