The program ultimately culminated with altitude testing at the NASA Glenn Research Propulsion Systems Laboratory from March - April 2000.
The FJX-2 engine was designed with many experimental systems and manufacturing processes to minimize parts count, lower production costs and have a bypass ratio of 4:1.
However, subsequent re-designs and the incorporation of more conventional systems resulted in the engine eventually meeting the NASA requirement of 700 lbf (3,100 N) thrust.
To achieve the required thrust-specific fuel consumption, the EJ22 turbofan was designed as a three spool engine having a fan, two axial compressors and three expansion turbines.
While very impressive on the test stand, the EJ22 proved quite temperamental during the two years of its development process and it was frequently subject to problems starting, overheating, part failures and various subsystem issues.