Dave,
Don't forget that X2 uses autorotation for cruise, so there will be a longitudinal cyclic trim position for minimum total drag (obviously with collective lowered). Actually, i'm not sure whether the FBW would need to keep an eye on longitudinal trim as well as collective. The idea of having to watch NR limits while cruising is an interesting thought - one for the TPs...
Ultimately, i have no doubt that X2 has been subject to the very latest CAE analytical techniques. So the question really remains how accurate are the predictions. If the project engineers believe the machine has the capability to achieve 240-250kias then i have no real reason to doubt them.
Chris, was all of the aero-mechanical-dynamics done in Ansys? Were there any other test beds to validate the CAE model?
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Dangermouse,
G-LYNX will always remain the worlds fastest single rotor helicopter. Credit where credit is due.
If i read the FAI definition properly then X2td still falls into the category of pure helicopter. X2 is
a rotorcraft with a power driven coaxial rotor system whose axes are fixed and substantially perpendicular to the longitudinal axis of the rotorcraft. I is confused?
