STRATFORD, Conn., Feb. 10, 2014 /PRNewswire/ -- Sikorsky Aircraft Corp., a subsidiary of United Technologies Corp. (NYSE:UTX), has powered up the engines and spun the rotor head on the first prototype CH-53K heavy lift helicopter -- designated the Ground Test Vehicle (GTV). The January 24 event continues the "Bare Head Light Off" phase of testing -- so named because it was conducted without rotor blades -- that began under auxiliary power in December with safety-of-flight test pilots at the aircraft's controls. (Photo: http://photos.prnewswire.com/prnh/20140210/NE62152-a) (Photo: http://photos.prnewswire.com/prnh/20140210/NE62152-b) (Logo: http://photos.prnewswire.com/prnh/20060403/SIKORSKYLOGO) "GTV main engines powered 'on' is a significant step for the CH-53K helicopter program," said Mike Torok, Sikorsky's CH-53K Program Vice President. "Having independently tested the aircraft's many components and subsystems, including electrical and avionics, hydraulics and flight controls, landing gear, propulsion, transmissions and rotors, now we have begun testing these critical functions as an entire system powered by the GTV aircraft's three GE 7,500 shaft horsepower class engines." Sikorsky delivered the GTV into the test program at the company's West Palm Beach, Fla.-based Development Flight Center in late 2012. Now anchored to the ground at its remote outdoor test site, the 44,000-pound GTV aircraft is outfitted at more than 1,300 points with sensors that will measure and verify the ability to operate safely under its own power. The GTV will undergo ground testing for approximately two years with both Sikorsky and U.S. Marine Corps test pilots at the controls. Once Bare Head testing is completed, Sikorsky will mount seven main rotor blades and four tail rotor blades onto the GTV. During this second test phase, Sikorsky will conduct extensive aircraft system checks leading to a formal Pre-Flight Acceptance Test required to clear the first flight aircraft for flight testing.