Sikorsky has moved its X2 technology demonstrator to the company’s West Palm Beach development flight test centre, signalling the start of the high-speed portion of the compound helicopter’s four-phase flight test program.

Built in the company’s Hawk Works unit in New York starting in 2005, the X2 completed its first flight in August 2008 and has accumulated roughly 15h of tests in phase one since then. Most recent flights engaged the helicopter’s propuslor unit, which includes a five-bladed rearward facing propeller that takes power from the single LHTEC T800 turboshaft engine and converts it to forward speed.

 X2 July2009


With the propulsor engaged, test pilot Kevin Bredenbeck recently achieved forward speeds of 52kt. Other work completed before the move included installation of the hub drag reduction fairings and the landing gear system. Bredenbeck in February said the X2 would reach 250kt (462 km/h) in the third or fourth quarter this year.

Sikorsky plans to fly as fast as 80kt, 120kt and 250kt in phases two, three and four, respectively, in West Palm Beach.

The X2 is designed to use its fly-by-wire control system, counter-rotating coaxial rigid composite rotors and the propulsor to enable “comfortable” low-vibration high speed cruise but to also maintain the manoeuvrability of a conventional helicopter at low speeds.