Framer this sector had been operated many times by pilots who would have experienced similar disrupted sleep patterns yet managed to get to and from Singapore.
The fact that many crews have done it before doesn't mean the next flight will also end well. It actually has no bearing on it whatsoever.
I'm not suggesting that the duty is inherently unsafe or fatiguing if the individuals operating it have success in managing their sleep leading up to the duty and on the overnight itself. I am more angling towards how the situation is dealt with by operations/management when someone isn't successful in getting the required sleep.
This was not an emergency situation
I understand that also, I didn't mean to give the impression that I thought it was. What I was getting at is that by the time they were on approach into Darwin at the end of the second sector the F/O had been awake for 18 hours. If they had had an emergency at that stage (ie unreliable airspeed or engine fire or similar), would he have been in good enough shape to deal with it given that he had been up for 18 hours on 5 hours disrupted sleep?
An 11.6 hour duty can be very taxing, are we doing enough to ensure the pilots starting these duties will be ok at the end of them?