The key challenges to the program are linked to spares availability. This is essential to support the aircraft retrofit program and to achieve the necessary aircraft flying Rate of Effort required to support test programs and the conduct of aircrew training. Australian Aerospace and the DMO have implemented strategies to manage these challenges, recover schedule and prevent further slippage. Improvement in the flying Rate of Effort has been made and is expected to continue as Australian Aerospace's maintenance and supply support networks become more effective.