The average descent rate from 3200ft down to 300ft (see # 16 & 304) seems to have been no more than 800ft/min. Even allowing for the airspeed decrease of 49 knots over this period, and possible flap deployment (of which we can only guess at this stage) this would seem to indicate there was some residual thrust available. In which case there could well have been adequate hydraulic and electrical power available without recourse to the RAT or Direct Law as some have suggested, so that the crew at least had a reasonably controllable aircraft. But all this will become clear later.
And 4 minutes would have allowed more than adequate time to start the APU. For sure in these circumstances this would have been a priority.
I would say the absolute key to the succesful outcome was the early decision to opt for the river landing, leaving the crew free to concentrate on this task. Any alternative, if indeed there was one, would have been highly fraught, with the risk of catastrophe.
This point needs making because it would appear a number of earlier posters disbelieved a successful ditching could be achieved with a large commercial aircraft, and seemed to perpetrate the myth that underwing engines would cause the aircraft to submarine on touchdown. Let us hope the publicity given to this event will dispel this particular notion.
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