Sikorsky’s coaxial X2 Demonstrator may have taken its last flight, but the rotorcraft’s design will serve as the basis for a new aircraft proposed by Sikorsky and Boeing. The companies will submit a joint proposal to build the new aircraft for Phase 1 of the U.S. Army’s Joint Multi-Role (JMR) Technology Demonstrator (TD) program that aims to deliver the next generation of vertical lift utility and attack aircraft.

Sikorsky’s X2 Demonstrator, which made its first flight in August 2008, is notable for its coaxial rotor design that sees its two main rotors counter-rotating on the same vertical axis. This configuration, coupled with a “pusher prop” at the rear of the aircraft supplying auxiliary propulsion and an advanced fly-by-wire system, helped the X2 set an unofficial world speed record for a helicopter on September 15, 2010, when it reached a speed of 250 knots (288 mph, 463 km/h) in level flight.

It is this proven design that Samir Mehta, president of Sikorsky Military Systems, says Boeing and Sikorsky will leverage to deliver an aircraft with an “efficient 230-knot (265 mph, 426 km/h) cruise airspeed, improved hover efficiency, and weigh-optimized design in an affordable package.” He added that the design would “offer the Army reduced risk, a 100-knot improvement in speed, a 60 percent improvement in combat radius, and 50 percent better high-hot hover performance."

The two companies will share leadership on the project, with Sikorsky taking the lead for the JMR TD Phase 1 proposal and Boeing taking the reins for Phase 2, which is the mission systems demonstrator program.

Phase 1 proposals must be presented to the U.S. Army Aviation Applied Technology Directorate by March 6, with the one or more winning bids expected to be announced in late 2013. The demonstrator aircraft will be expected to be in the air in 2017.

Sources: Boeing, Sikorsky