Recently the Royal Australian Air Force (RAAF) has been considering an upgrade to the F/A-18 aircraft in Australia. This upgrade may well involve the modification of Mission Computer (MC) systems. Maintaining correct functionality for the upgraded F/A-18 is therefore a major concern for the RAAF. This particular problem received interest from CSIRO and DSTO to support a joint Research Fellowship to investigate specification of hard real-time characteristics by formal method approaches.