The Managing Contractor tender/evaluation was separate to and somewhat ahead of the replacement project.
The intent of the Managing Contractor was to effectively take up the role of CASG and do complete capability management for the Commonwealth (ownership function). For reasons I am not aware, this proposal was not adopted, the Commonwealth remains the manager of the SPA capability (CASG).
NGA is the contracted provider of engineering, maintenance and logistics sustainment of the capability. NGA is contracted by CASG for this capability - this arrangement would have occurred under the Managing Contractor if the above proposal was adopted.
The replacement/extension of the aircraft to provide the capability (604 and BBJ was looked at) was conducted as an Air Force project. Various options were looked at.