I get the opportunity to make crosswind landings in the 330 with anywhere from a 10 to 30 knot direct component fairly regularly so this is my 2 pesos. These are just observations gleaned from drinking myself into an obsessed self-analytical stupor after making a few LEGENDARY "crunch-on" crosswind "arrivals". They have since gotten a bit better. Read on for some ideas; take what you can use and chuck the rest.
In normal law, roll and yaw control remains the same until the main wheel touchdown, at which point lateral control blends down to a direct stick-to-deflection relationship.
Pitch, on the other hand, changes to a direct stick-to-elevator relationship around 100 ft RA. Autotrim also stops, and at 50 feet a slight nose-down moment is applied to get you to pull through in the flare. This all combines to basically make the airplane feel like a Cessna 172 IN PITCH during the flare and touchdown, assuming the autothrust isnt jumping around too much. In roll, if you use a "kick-out in the flare" kind of technique and have a gentle touch on the stick, it also will feel fairly intuitive if you just look out the window and fly it.
Autothrust, however, can really mess up the feel of the flare on a gusty day.
In Normal Law ABOVE 100 ft, the FBW maintains 1 "G" corrected for pitch, regardless of gusts or thrust changes. That does not mean it will necessarily hold the PITCH exactly stable, but the G LOAD; subsequently the pitch stays pretty close. So let's say as you motor down short final, you hit a big old sinker and lose a few knots below Vapp (assume we are below 400 ft so GS Mini has stopped "mini-ing", and above 100 ft so we are still in fully normal Normal). The airplane will hold CLOSE to the current pitch as the FBW applies up elevator to increase "G" against the "sinker". Simultaneously (actually a little after), the A/THR will blast in some power to bring up your speed. This would conventionally cause a non-FBW airplane to pitch UP due to "pitch-power couple", but of course the FBW counters this as well. So to you the airplane's path feels fairly steady, with no input needed on your part except for small little "guiding" touches when the path wanders off as the airplane works to maintain "G".
Now we get into "flare mode", below 100 feet. Remember our PITCH CONTROL ONLY has returned to a DIRECT relationship between stick and elevator, with no autotrim. A/THR, however, is STILL in "SPEED" mode. Let's say you hit that same sinker NOW, at 80 feet. The nose will drop with the "sinker", and you will correct for it. This feels natural and lets us have an intuitive feel for the airplane's energy state just above the ground, where it matters most. However, as the power surges in the "pitch-power couple" is also back with us, and the nose wanders up and down. In a Boeing, we have our hands on the throttles and feel them moving, giving us an instinctive grasp of what the power, and therefore the pitch, will do. On Airbus aircraft that is not the case. You really don't know what the hell the thrust is doing until a split second after it "does", because you are looking out the window and the engines are too far back to hear until they really crank up. So when the autothrust starts jockeying itself in gusty winds just above the flare, a lot of "stick-and-rudder" type pilots will feel just a touch "out of the loop".
So going back to the gusty crosswind landing, if your SOPs allow it, manual thrust is much more intuitive, assuming you have practiced using it. A good technique on the A330-200 is to set the power for around 1.6 ~ 1.7 EPR while all set up and riding down final. Use small power changes (.1 or less) to counter airspeed TRENDS, and allow the exact IAS to wander slightly in the gusts, preferably on the higher side. The autothrust is rough in gusts because it AGGRESSIVELY tries to maintain the EXACT speed at low altitude; maintaining ENERGY STATE is more the name of the game hand flying. It is also MUCH smoother on the passengers' ears (and the neighbors' around the airport).
Most important this puts the pitch-power couple COMPLETELY back in your hands, taking away the variable that seems to destabilize crosswind landings more than any other IMHO.
So we have pitch dealt with. Now the lateral. Roll stays in Normal (roll-rate demand) till the ground. So same as pitch, it will NOT lock in your bank angle, but your RATE. So zero stick deflection equals zero rate. It will try to correct back to zero if it is disturbed, and that correction puts it back more or less where it started, but not always. So there will be some "guiding" to do here as well BUT NOT MUCH. That does mean that as you squeeze out the crab angle with the rudder, it will try to hold zero roll rate. It does a good job of this right up to the point that a gust nails you in the de-crab. NOW, it will zero the roll rate but not always exactly on wings level. This is where we usually start "stirring the pot" and it gets really wonky (like the Lufthansa A320 near-accident a while back). Small, steady motions are the key. Big, steady motions if those don't do it, but above all steady and not jerky. Think Cessna 152 more than Boeing 747. Remember a given lateral stick deflection commands a given roll rate; the airplane may take a moment sorting out how to give that to you, so hold the command STEADY until it either starts moving in the right direction or you are ABSOLUTELY sure that it will not. Let it do the work for you; by getting your control inputs "out of phase" with what the airplane is trying to do for you, the famous "Airbus Hula" will begin and your landing is SHOT.
The secrets of the guys I've seen who do really good crosswind landings mostly involve:
Use manual thrust. Since you are controlling thrust directly now, idle the throttles slowly like you would in a Boeing, to reduce pitching tendencies. Squeeze out the crab as late as possible DURING the flare and not before, to minimize lateral stick corrections. Small, STEADY pressures on the stick; use STEADY, CONSTANT PRESSURES in pitch below 100 ft, with small, STEADY, intermittent pressures in roll that ALWAYS RETURN TO NEUTRAL.
And even then sometime the damn thing just drops like a brick, and lands itself on the wrong wheel while everyone else in the cockpit laughs at you.
Good luck!
Last edited by hikoushi; 8th Nov 2014 at 08:52.