Originally Posted by
ILUV767
Flight crews are limited to 8 hours of duty. On flights where the block time is over 8 hours, they carry a relief crew.
With the initial push back at 23.30 (SFO time) to switch off engine time in SYD 10.00 the block time would have been 15.5 hours so I figure if the flight had been delayed another 30 minutes they might have might not departed at all.