Depending on some variables such as a/c speed and the amount of water on the runway, without spoilers, there is a very strong chance that the a/c was aquaplaning when brakes were applied. The video evidence shows that there must have been some standing water as the spray pattern from the operating reverser is very noticeable.
If it was aquaplaning, there is very little chance that the brakes would have had any significant effect until the wings were travelling slow enough to stop producing any lift. At 94kts, I would have thought there would still be significant lift and if only the spoilers had been deployed, they may have had a fighting chance of stopping within the boundary of the airfield or at least gone over the edge with less energy.
Can the ground spoilers on the A320 be deployed manually if they didn't do so automatically due to the thrust lever positions?
Danny,
It may be possible that aquaplaning contributed to the aircraft's speed off the runway, but, based on the AIT posted here
http://www.pprune.org/forums/showthread.php?p=3457705#post3457705 and some preliminary FDR info posted here
http://www.pprune.org/forums/showthread.php?p=3463553#post3463553, there has been nothing published that strongly suggests aquaplaning did occur.
From the above sources touchdown was in the touchdown zone at 140 knots and the aircraft travelled for approx 11 seconds at about that speed before maximum braking was applied. This suggests that deceleration started about 1000-1200m down the runway leaving at most 880m left to the end.
The AIT says that the aircraft over-ran the runway (in fact we know it left the side somewhere before the end) at approximately 100 knots. So, the speed decreased by about 40 knots within a maximum distance of perhaps 880m. As the kinetic energy of the aircraft varies in proportion to the square of its velocity the ratio of the aircraft's energy off the end of the runway to its energy at the start of maximum braking looks to be about 100²/140² = 51%.
That would suggest about a 49% decrease in aircraft energy achieved over at most 880m by nothing but the brakes and the one reverser while fighting against the other engine at 1.20 EPR and a wet runway. My guess is that this would be a pretty good result all things considered. In my guesstimate above the minimum ground stopping distance would have been 1520m (1820-300). If the stopping force available from the brakes remained fairly constant (and I don't know that to be true - if anything I'd expect it to rise due to greater weight on the wheels) by guesstimation it would have required at least 750m to reduce from 140 kts to 100 kts. So, if the aircraft actually achieved something within a 100m or so of that value then it's unlikely that significant aquaplaning occurred.
With respect to manual extension of the ground spoilers on the A320 the answer is no. There was some discussion of this a ways back in the thread.
ELAC