All good points that are mentioned here, but all of them are assuming the operating pilots were properly rested and in possession of normal skills. It is known that China Airline's pilots have been submitted to very harsh FTL by the Taiwanese Aviation Authorities in the last 2 years. We all know the meaning of chronic fatigue! While we are all siting in our homes trying to understand what has happened the best is to imagine the last time we had a couple of drinks and we were not in good condition to drive our car, to imagine taxying a 747 in poor visibility with icy taxiways under the influence. I hear some colleagues stating they would slow down....chronic fatigue is a killer.