The GEnx engine is the second of two engine types offered to customers of the Boeing 787 Dreamliner. The four aircraft already in the flight test fleet are powered by Rolls-Royce Trent 1000 engines.
The GEnx engine has a front fan case and fan blades made of carbon fibre composites.
"We're pleased to introduce the fifth Dreamliner to the flight-test fleet and to start flight testing with GE engines," said Scott Fancher, vice president and general manager of the 787 programme for Boeing Commercial Airplanes.
"ZA005 will be used to test the General Electric engine package and demonstrate that the changes made with the new engine do not change the airplane's handling characteristics."
The sixth, and final, 787 Dreamliner to join the flight test programme is expected to fly before the end of July.
Delivery of the first Boeing 787 is planned for the fourth quarter of 2010.
