Sikorsky tested its experimental X2.
"The X2 TECHNOLOGY Demonstrator is designed to establish that a
helicopter can cruise comfortably at 250 knots, while retaining such
desirable helicopter attributes as excellent low speed handling,
efficient hovering, and safe autorotation, combined with a seamless and
simple transition to high speed."
The innovative helicopter is planned to be significantly faster than existing helicopters.
"The milestone culminated more than four years of design, development
and testing of the Demonstrator aircraft’s suite of technologies that
are intended to advance the state-of-the-art, counter-rotating coaxial
rotor helicopter."
(Image: Sikorsky)