Originally Posted by
parishiltons
The information provided so far does not necessarily suggest a failure of surveillance feeds, but is pointing to other factors. I can't see any safety failures here, ATC has prima facie responded to a reduction in system capability and capacity by moving traffic at rates that are safe commensurate with the status of the ATC system at any given point in time.
Sir, you are missing the point. It does not matter in the slightest what actually failed. What matters is that a failure has occurred such the the system is so degraded that ongoing capacity is now limited - as you point out. But at the time of failure, there could have been more aircraft in the airspace around Sydney than could safely be managed without the radar. Had the failure happened at 0820 instead of 0520 for example?
The safety management system and its oversight is intended to ensure that no single failure (or failure 'chain' consequent on a single failure) can prejudice the safety of any aircraft.
The very fact that traffic handling is now limited is proof that whatever fault did occur, so limited traffic handling that aircraft in the airspace between the time of failure and the time at which the traffic numbers were reduced suffered a reduction in safety assurance.
The safety system and its oversight is intended to preclude that situation.