Bon, vous avez sans doute tous au moins le niveau 5 du FCL 1.028…et vous maîtrisez également parfaitement toutes les subtilités du « Fly-by-wire »…?….alors vous allez prendre du plaisir à lire ceci : ou comment les anglais vivent l’airbus dans le vent de travers :

We must remember that the Airbus Flight Control system is based on « rate inputs ». The wing will always look at the last bank angle and will try to return to that point, you may not see the input by the flight controls, but it is being provided.

So, if you are rocking down on final due to gusty winds, or for that reason on the final portion of the flare. Should you apply correction in the opposite direction of where the wing is coming up, because of the gust, then you are adding more input to the Flight Controls computer’s, reacting to bring the wing to the last known position with a bigger input increment (you have just Augmented that input), which will then force you to react in the opposite direction with more sidestick deflection. Hence, the feeling that you are running out of control deflections in the sidestick, you are just inducing a P-CIO (Pilot-Computer Induced Oscillations).

If you were to have a direct right crosswind of 29 knots, fly the aircraft, don’t mind the gust (unless it is hurricane David), around 50 feet, start kicking your left rudder (and power as necessary), and as the left wing tries to come up (due to the Aerodynamics of the rudder inputs attempting to bring the right wing up), put the necessary right joystick (squirts) input and let go, squirt and let go, as necessary to keep the nose of the aircraft tracking down the centerline while adding rudder as necessary, then once the aircraft is tracking where you want him to, relax the bank inputs on the joystick, just work with the pitch for the flare and round out.

Touch down with the right main gear, right spoilers deflect, fly the left wing down nice and easy, while relaxing ruder input and squirting the bank inputs as needed… It is exhilarating and a great aircraft

Do not hold the side stick input, just let it go… Give it the bank squirts inputs required to work the gust with just minor inputs to keep the wing down as you increase rudder for that amount of gust. The wing, will stay down, because the system recognizes that point to be the new wings level position requested by you… In this manner, you can maintain right wing down, for as much as it is needed to keep the nose tracking on centerline. Of course, you can land in a 45 knot crosswind with this aircraft, should you need to, but I don’t know how much bank would require to scrape a wingtip with the struts compressed and vice versa.

There is a confidence builder exercise I use when fellow pilots have doubts on what I just mentioned. With flaps 3, gear down, out by the marker or before while on the ILS GS Path, « VFR ». The ECAM page will be on the brakes and gear page, below on the bottom of that page, it shows flight spoilers and ground spoilers deflection, because that is the page you will look for the ground spoiler’s and the PNF call outs of « Spoilers » and « Two Reverser’s » etc.

Disconnect the autopilot and start a very slow rudder deflection (it will not be felt in the back, just don’t be abrupt), while keeping the wings level with just small sidestick bank inputs, as required to keep the wings level, keep increasing rudder input slowly, and watch the flight spoilers on the opposite side of rudder input (i.e. right rudder, left wing), watch them come up and stay there, even when you are not providing left sidestick inputs. The computers are now telling the wing to stay wings level, but the rudder deflection is causing the flight spoilers to come up for that purpose.

You are doing this at approach speed, just like you would in the flare to keep the nose tracking down the centerline, so there are no side loads exceedances to the airframe or tail while performing this mild maneuver, this is exactly the same as de-crabbing for landing, but you can see the results way out there…Just don’t be abrupt with the rudders, do it gentle, avoid any PIO’s.

Initially, it will be a conscious effort, but with a few good crosswinds, you will automatically perform the maneuver in the worst case of crosswinds. The aircraft is an excellent crosswind lander, it is great design, and I do not, by any means intend to brag about this, just wish you confidence in the system.

This is something that should be shown to any new pilot, by the training department, in the simulator, or during the IOE. I see many guys out there still having difficulty, because they do not understand what the Flight Control Computers are inputting to the flight control surfaces… « Rated Inputs ».

We must remember that the Airbus Flight Control system is based on « rate inputs ». The wing will always look at the last bank angle and will try to return to that point, you may not see the input by the flight controls, but it is being provided.

Airbusdriver.net

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Tags: Atterrissage, travers, vent