They were not realy able to control the airspeed too well.........Pull the power off....airspeed drops.....nose drops, aircraft descends.....airspeed starts increasing again...nose rises.....if is increases too much the nose comes up again by itself....
They had to descend like this the whole way down......I think it's called feugoid motion.
In addition the aircraft sustained damage on the starboard side of the No2 Engine cowl.......which induced drag on that side.....so the aircraft had a tendency to yaw and hance roll to the right.
So engine 3 had, at all times to be at a higher power setting than engine 1 to counteract this tendency.
In addition, there was no hydraulic pressure to deploy any Flaps or slats.....(gear was lowered by emergency system which uses gravity)....although the pitch change induced in doing so would probably have led to loss of control...........So the approach speed was in the region of 220 kts.
If the aircraft did'nt have the yaw/roll tendancy, I suspect the crew would have been able to get the aircraft on the ground in one piece.
All in all it was a supreme feat of airmanship that the crew were even able to manage an approach, let alone actually get the aircraft to a runway.