Sikorsky has flown its coaxial-rotor X2 Technology demonstrator, in secret. To keep the private-venture project out of the public eye, the company took the unusual step of flying the small helicopter indoors. But in a blow for Sikorsky security, clandestine video of the secret first flight has been posted on youtube.
From the video, it’s clear the initial flight was conducted in hover mode and the tail-mounted propeller, which is expected to push the X2 to speeds as high as 250kt, was not engaged. The helicopter, which has a pair of rigid contra-rotating rotors, lifts off quickly, but appears “twitchy” in the hover. Another potential problem is the noise, which one observer describes as “irritating as h*ll after a few seconds”.