Dave, unfortunately i suspect there may be some internal politics going on. I have quietly wondered whether there has been an incident which damaged the machine - i sincerely hope not. A project of this nature is not going to be cheap, and will tie up many engineers during it's development. I imagine much of the groundwork has already been done on the ABC.
Getting everything stiff enough, while keeping mass low, will be a headache. The one problem i am aware of is flexure in the extended driveshaft to the top rotor. Sikorsky may have been overly ambitious on rotor clearance/flexure.
This is what got me thinking about the asym-wing concept as a quick and dirty method to achieve the X2 intended performance. The Comanche parts bin could also be further used, particularly that 15% hinge offset rotor. The final design may not be a pure helicopter, but so what as long as the machine delivers 250+kts...
Last edited by Graviman; 23rd Sep 2007 at 09:14.