A few more comments.
Taking out the autopilot at 1600 feet was entirely appropriate for this long haul flight. Making small corrections in pitch and roll via the automatics has a lag and is not easy on a visual approach. It is easier to disconnect the autopilot and point the nose where you want it.
The 777 is a large aircraft but quite light on the ailerons and it is common for people new on type to over control a little and take a bit longer to nail the centreline.
Although we are allowed to build an approach in the FMC for approximate glide slope guidance we are not allowed to fly the approach in VNAV unless it is in the database.
In thousands of hours on the 777 and hundreds of approaches I have never flown an approach where the autothrottle has failed to maintain the Vref but then I have always been aware of the flight mode I was in. The only time I have ever disconnected the autothrottle in flight was for a TCAS RA. We are not allowed to practice autothrottle disconnected approaches in the 777 as Boeing do not recommend it. We do practice them in the simulator though.
In the scenario described with V/S of 1500 fpm the autothrottle would have maintained the speed at Vref plus 5 knots once the speed had come back to that point. So at some later stage the mode must have been changed to one where the autothrottle stayed in "hold" and maintained idle thrust. FLCH or VNAV SPD would do this. Or as has been mentioned earlier if the handling pilot is resting his hands heavily on the thrust levers this death grip could prevent the thrust levers from opening up.
The low speed warning on the Eicas would still work, even if in FLCH, but probably came at about 150 feet when with the low speed and rate of descent and with the drag of flap 30 and gear down it would have been too late to be of any use.
As in all accidents there are a number of factors. I think the most significant one and the main technical cause of this accident is failure of the autothrottle to maintain the target reference speed for as yet undetermined reasons and the failure of the operating flight crew to realise until it was too late.
Last edited by suninmyeyes; 10th Jul 2013 at 16:44.