 Until 2015, issues were mostly oil-fuel heat exchanger problems, carcass distortion and clearance control challenges of the high-pressure section.Optimizing the settings, the control laws and positioning of the variable stator vanes will recover a part of the losses, but not all.Flowpath will not be too modified and no stages or vanes will be added, the fixes selection will establish the length of the delay and the schedule will be revised before 2017 ends to recover all the surge margin and to operate as planned across the flight envelope.