<p>
</p>
<p>It is called settling with power (vortex ring state) and is common to every helicopter that has ever been manufactured. Heavy, hot (or high altitude), steep, and slow; it is almost certain to happen which was exactly where the V-22 with the load of Marines happened to be. You would probably be surprised at the number of Chinook Army deaths in either the mountains of Afghanastan or the heat of Iraq attributable to this aerodynamic reality. </p>
<p>I also hope the Army doesn’t get the Osprey. That will leave all the edge-of-the-envelope missions and the appropriation dollars associated with them, to the SEALs and the Recon Marines.</p>
<p>Like Zap stated, all new technology has a learning curve.</p>