As a pilot myself, I hesitate to cast shade on a fellow pilot, but in this case I think the A380 pilot blew it.
For non-pilots, there are two accepted techniques for crosswind landings. The first is called "crabbing" (because the aircraft is flying partially
sideways, similar to the way a crab moves). In that technique, the pilot sets the pitch attitude (nose up) and the throttle to give the correct glide
slope and approach airspeed. Additionally, the pilot holds the wings level and uses the rudder to point the aircraft nose off the runway centerline
and into the wind (the "crab angle"). By using the rudder only, it's fairly easy to keep the center of mass of the aircraft on the runway centerline
and moving in the direction of the runway, but the pilot may have to look out the side window to keep the runway in sight during the approach. The
problem is that if you touch down with the fuselage pointed in the direction of the crab angle, the aircraft will immediately jerk and try to run off
the runway in that direction. If you overcorrect, it will try to run off in the other direction. This is exactly what the A380 pilot did in this case,
as manuelram16 pointed out. So the trick is to neutralize the crab angle by using the rudder at the exact instant the wheels touch the runway. That
takes a lot of practice.
The easier technique is called "slipping" to a landing. In that technique, the pilot likewise sets the pitch attitude and the throttle to give the
correct glide slope and approach airspeed, but banks into the crosswind while cross controlling with the rudder in order to remain on the runway
centerline. In a slipped landing, you maintain the controls steady until just before touchdown, and then slowly and smoothly relax the bank angle and
rudder to their neutral positions. Because the fuselage is always pointed in the direction of the runway centerline during a slip landing, there is a
much reduced likelihood of the aircraft trying to veer off the runway. Also, the final controls adjustment just before touchdown consists primarily
of removing the rudder and aileron angles and allowing them to go back to their trimmed settings; that doesn't require exquisite coordination and huge
amounts of practice to get it right--the aircraft naturally wants to do that. (Actually, you want to touch down with just a small amount of bank
angle remaining so that the upwind main landing gear touches down immediately before the downwind tire does; with a tricycle landing gear setup that
makes the landing smoother.)
So why didn't this pilot execute a slip landing? Because the Airbus operations manual says not to. From what I've been able to find out, the Airbus
autopilot doesn't like it when the human pilot tries to fly the aircraft with crossed controls (the ailerons trying to turn right, for example and the
rudder turning left)--and a slip landing is definitely a crossed control example. Apparently, Boeing autopilots don't have this characterIstic so
777's, for example, can and do begin a slipped approach to landing when they're within about 400 feet of ground level. My understanding is that the
Airbus manual says the pilot should execute a crabbed approach until just before touchdown and then--in quick succession--align the fuselage with the
runway using the rudder, bank into the wind by using the ailerons to lower the upwind wing, and then cross control with the rudder to keep the
aircraft on the runway centerline. Essentially, you're supposed to execute a crabbed approach to the last few seconds of flight and then immediately
enter a slipped approach attitude.
The way it looks to me, this is exactly what the A380 pilot was attempting to do. The problem is that he seemed to have run out of altitude about 1
or 2 seconds before he would have completed the maneuver. He overcorrected the yaw maneuver (actually flying with the crosswind instead of against
it) and did not have time to get the fuselage aligned with the runway before the landing gear touched the pavement. Simultaneously, it looks like he
was trying to bank slightly right into a slipped approach attitude but didn't get very far with that maneuver either, before the landing gear touched
down. It seems to me that this approach puts a heavy cognitive workload on the pilot at exactly the moment of touchdown. If the pilot had begun his
transition from crabbed approach to slipped approach even a few seconds earlier, it could have been a much less dramatic landing.
If there are any Airbus pilots here, please let me know if my understanding of their practices and procedures isn't correct.
a reply to: FredT