ABSTRACT
Helicopter is a VTOL vehicle that can hover and perform excellently at low altitude. Normal configured helicopter has inherent defects because of the rotor motion mode. Since the midtwentieth century, countries in the world began to try a variety of compound configurations to break through the speed and performance limitation of helicopters. In 2010, X2 coaxial compound helicopter from Sikorsky Aircraft Corporation broke the record of ‘Lynx MK’, 1986, by 259 miles per hour[1], sparking great concern, while domestic development still remains in theoretical area.
