GE is dusting off an old test rig in an attempt to develop a more efficient engine, they want to test an open rotor system:

For the wind tunnel tests, NASA is refurbishing testing rig equipment used in the 1980s when the agency and GE jointly tested the GE36 unducted fan, which was later mounted on the aft fuselage and flown on a Boeing 727 and an MD-80.

Same as it ever was.