Originally Posted by
Intruder
Not quite...
In the 744 there will be no autothrottle, so no Cat 3 capability for most operators. In any case, it is not "full" Cat 3 capability.
As for DAL167, while it is POSSIBLE to continue from SEA-NRT with a dual FMS falure, I would not consider it smart. Pilot workload would be increased significantly, including a HUGE workload increase in the terminal area at the end of a long flight. With so little tolerance for deviation from the norm these days, returning to SEA was a good move.
Also, while it might not be a true "emergency" situation that had high risk to life & limb, declaring an emergency is often the only way to get priority handling so fuel dump and return can be accomplished.
Just get vectors to final in the terminal area. No need to declare an emergency to dump fuel(normally) and no need to declare an emergency to divert to another airport.
But, it appears that oceanic airspace may not be allowed due to entry requirements of 1 FMC. (Please provide a link to show this). Would it make sense to consider a re-route further north onto a Russian Route in order to continue and perhaps refuel in Sapporo?