Mart & CEFOSKEY,
Many years ago Nick mentioned that Sikorsky does 90% of its helicopter development after the prototype has been built and is in testing.
Perhaps we have differing perspectives as to the meaning of
'90% of helicopter development'.
IMHO, development is all inclusive; from the initial product conceptualization on through to the start of production.
What is done once the prototype is built and outside the barn door (flight testing, etc.) consists of refinements to the engineering that was previously done inside the barn.
Dave
PS.
The X2 ain't bilaterally symmetrical.
The engine is on the port side and the propeller's drive-shaft is on the starboard side.
But, since it's on the inside and doesn't affect aerodynamics ......
