Narrative:

The flight was scheduled and flown from ZZZ1 to ZZZ. The only anomaly we noted prior to the event was that as we did our single engine taxi from the gate in ZZZ1; just as I was about 1/2 way through my first turn to the left away from the gate; we received a master caution with an ECAM message stating the flight controls were in alternate law. First officer looked up to the overhead panel to see if any flight control computers had faulted; none had; while I rolled out of the turn. By the time we looked back at the ECAM screen; the message went away. Figuring it was simply a momentary false warning (we do get quite a lot of those); we continued on. The flight was flown normally and the aircraft behaved normally. On the descent; I turned off the autothrust and autoplt system and hand flew the approach. We were in light turbulence for about the last 10 mins of the flight; and there were no excursions outside what you would call normal for that amount of turbulence. For the final approach; the jet was pointed just a few degrees to the right of the runway centerline due to a crosswind. At around 50 ft AGL; I input left rudder to align with the runway. I applied the normal amount of force; felt nothing and noticed no movement of the nose. At this point I can say that I still didn't feel that anything was wrong. I pushed harder; this time about twice as hard as I normally do; and that's when my thoughts went to the 'uh-oh' mode when I had noted no yaw yet. I pressed a little harder and the rudder pedal immediately (soundlessly) snapped forward. The nose yawed immediately left at the same time. I stopped the rudder; applied less pressure on the left pedal so as to use just the right amount required to align to the runway; and I continued the flare maneuver and landed. The amount of time it took for all this to happen I'll estimate at around 3 seconds. During the landing roll; immediately after touching down; I asked the first officer if he had his feet on the pedals. He had his feet flat on the floor; so it wasn't him. Also; it didn't feel like a 'heavy' pedal; one that had someone else's appendage on it -- it felt like it froze and abruptly broke free. After taxiing clear of the runway; we both did multiple full rudder deflections with no adverse feel or effect. We watched the ECAM screen and it showed that the rudder was moving along with our pedal inputs. There was a small 'bump' each time I pushed the left rudder pedal just a little bit into the movement. I call it a bump for lack of a better word; it was just a little tiny thing. The movement was not hampered in any way by it; but it was definitely a 'hitch' in the otherwise smooth rudder movement. It felt almost like just the slightest slop in the linkage that would catch up right there. It was so slight that I almost didn't mention it in this report; but when the first officer did his rudder pedals; he felt nothing but smooth movement. I couldn't feel it when pushing the right pedal; only the left. The concern I have with zeroing in on this bump is that it happens a little way into the movement; instead of at the top of the movement like had happened on approach (although it would be hard to say exactly where in the movement cycle the freeze-up occurred based on my leg movement; there was no noticeable nose yaw until it broke free; meaning to me that the pedal didn't move at all until it came loose. Fdr information will have to be checked to see if; just a second or so prior to the break; the rudder pedals did in fact move and if there was a slight controled left yaw induced that I could have missed in the light turbulence). I'm not completely discounting this particular spot in the movement as 'the' freeze point; just pointing out that not all the facts seem to support it. At the gate; I searched under and behind both rudder peals to see if there was anything there that could have caused the problem. I saw nothing at all; but noted that this particular aircraft didn't have the FOD/dirt/dust screen on the center pedestal where the rudder pedals move forward and back (the 'plastic grass' that guards the area around and under the pedals). The lack of this guard made it easier to look down into that area; but like I said before; all I could see was lots of dust and dirt. There was no noise before; during or after the incident. There was no grinding noticeable. The rudder indication on the ECAM screen smoothly followed all rudder inputs. The outbound captain opened the east&east compartment to see if he could see anything from underneath; and he; too; looked for any foreign objects and could find nothing. I called maintenance and coordination with ZZZ1 operations to start the ball rolling for the mechanical delay and maintenance problem. I realize this is a fairly complex issue and I hope to have given you enough information to work with.

Google
 

Original NASA ASRS Text

Title: AN A319 CREW EXPERIENCED A RUDDER ANOMALY DURING LNDG RESULTING IN PEDAL RESISTANCE AND REDUCED RUDDER MOVEMENT.

Narrative: THE FLT WAS SCHEDULED AND FLOWN FROM ZZZ1 TO ZZZ. THE ONLY ANOMALY WE NOTED PRIOR TO THE EVENT WAS THAT AS WE DID OUR SINGLE ENG TAXI FROM THE GATE IN ZZZ1; JUST AS I WAS ABOUT 1/2 WAY THROUGH MY FIRST TURN TO THE L AWAY FROM THE GATE; WE RECEIVED A MASTER CAUTION WITH AN ECAM MESSAGE STATING THE FLT CTLS WERE IN ALTERNATE LAW. FO LOOKED UP TO THE OVERHEAD PANEL TO SEE IF ANY FLT CTL COMPUTERS HAD FAULTED; NONE HAD; WHILE I ROLLED OUT OF THE TURN. BY THE TIME WE LOOKED BACK AT THE ECAM SCREEN; THE MESSAGE WENT AWAY. FIGURING IT WAS SIMPLY A MOMENTARY FALSE WARNING (WE DO GET QUITE A LOT OF THOSE); WE CONTINUED ON. THE FLT WAS FLOWN NORMALLY AND THE ACFT BEHAVED NORMALLY. ON THE DSCNT; I TURNED OFF THE AUTOTHRUST AND AUTOPLT SYS AND HAND FLEW THE APCH. WE WERE IN LIGHT TURB FOR ABOUT THE LAST 10 MINS OF THE FLT; AND THERE WERE NO EXCURSIONS OUTSIDE WHAT YOU WOULD CALL NORMAL FOR THAT AMOUNT OF TURB. FOR THE FINAL APCH; THE JET WAS POINTED JUST A FEW DEGS TO THE R OF THE RWY CTRLINE DUE TO A XWIND. AT AROUND 50 FT AGL; I INPUT L RUDDER TO ALIGN WITH THE RWY. I APPLIED THE NORMAL AMOUNT OF FORCE; FELT NOTHING AND NOTICED NO MOVEMENT OF THE NOSE. AT THIS POINT I CAN SAY THAT I STILL DIDN'T FEEL THAT ANYTHING WAS WRONG. I PUSHED HARDER; THIS TIME ABOUT TWICE AS HARD AS I NORMALLY DO; AND THAT'S WHEN MY THOUGHTS WENT TO THE 'UH-OH' MODE WHEN I HAD NOTED NO YAW YET. I PRESSED A LITTLE HARDER AND THE RUDDER PEDAL IMMEDIATELY (SOUNDLESSLY) SNAPPED FORWARD. THE NOSE YAWED IMMEDIATELY L AT THE SAME TIME. I STOPPED THE RUDDER; APPLIED LESS PRESSURE ON THE L PEDAL SO AS TO USE JUST THE RIGHT AMOUNT REQUIRED TO ALIGN TO THE RWY; AND I CONTINUED THE FLARE MANEUVER AND LANDED. THE AMOUNT OF TIME IT TOOK FOR ALL THIS TO HAPPEN I'LL ESTIMATE AT AROUND 3 SECONDS. DURING THE LNDG ROLL; IMMEDIATELY AFTER TOUCHING DOWN; I ASKED THE FO IF HE HAD HIS FEET ON THE PEDALS. HE HAD HIS FEET FLAT ON THE FLOOR; SO IT WASN'T HIM. ALSO; IT DIDN'T FEEL LIKE A 'HVY' PEDAL; ONE THAT HAD SOMEONE ELSE'S APPENDAGE ON IT -- IT FELT LIKE IT FROZE AND ABRUPTLY BROKE FREE. AFTER TAXIING CLR OF THE RWY; WE BOTH DID MULTIPLE FULL RUDDER DEFLECTIONS WITH NO ADVERSE FEEL OR EFFECT. WE WATCHED THE ECAM SCREEN AND IT SHOWED THAT THE RUDDER WAS MOVING ALONG WITH OUR PEDAL INPUTS. THERE WAS A SMALL 'BUMP' EACH TIME I PUSHED THE L RUDDER PEDAL JUST A LITTLE BIT INTO THE MOVEMENT. I CALL IT A BUMP FOR LACK OF A BETTER WORD; IT WAS JUST A LITTLE TINY THING. THE MOVEMENT WAS NOT HAMPERED IN ANY WAY BY IT; BUT IT WAS DEFINITELY A 'HITCH' IN THE OTHERWISE SMOOTH RUDDER MOVEMENT. IT FELT ALMOST LIKE JUST THE SLIGHTEST SLOP IN THE LINKAGE THAT WOULD CATCH UP RIGHT THERE. IT WAS SO SLIGHT THAT I ALMOST DIDN'T MENTION IT IN THIS RPT; BUT WHEN THE FO DID HIS RUDDER PEDALS; HE FELT NOTHING BUT SMOOTH MOVEMENT. I COULDN'T FEEL IT WHEN PUSHING THE R PEDAL; ONLY THE L. THE CONCERN I HAVE WITH ZEROING IN ON THIS BUMP IS THAT IT HAPPENS A LITTLE WAY INTO THE MOVEMENT; INSTEAD OF AT THE TOP OF THE MOVEMENT LIKE HAD HAPPENED ON APCH (ALTHOUGH IT WOULD BE HARD TO SAY EXACTLY WHERE IN THE MOVEMENT CYCLE THE FREEZE-UP OCCURRED BASED ON MY LEG MOVEMENT; THERE WAS NO NOTICEABLE NOSE YAW UNTIL IT BROKE FREE; MEANING TO ME THAT THE PEDAL DIDN'T MOVE AT ALL UNTIL IT CAME LOOSE. FDR INFO WILL HAVE TO BE CHKED TO SEE IF; JUST A SECOND OR SO PRIOR TO THE BREAK; THE RUDDER PEDALS DID IN FACT MOVE AND IF THERE WAS A SLIGHT CTLED L YAW INDUCED THAT I COULD HAVE MISSED IN THE LIGHT TURB). I'M NOT COMPLETELY DISCOUNTING THIS PARTICULAR SPOT IN THE MOVEMENT AS 'THE' FREEZE POINT; JUST POINTING OUT THAT NOT ALL THE FACTS SEEM TO SUPPORT IT. AT THE GATE; I SEARCHED UNDER AND BEHIND BOTH RUDDER PEALS TO SEE IF THERE WAS ANYTHING THERE THAT COULD HAVE CAUSED THE PROB. I SAW NOTHING AT ALL; BUT NOTED THAT THIS PARTICULAR ACFT DIDN'T HAVE THE FOD/DIRT/DUST SCREEN ON THE CTR PEDESTAL WHERE THE RUDDER PEDALS MOVE FORWARD AND BACK (THE 'PLASTIC GRASS' THAT GUARDS THE AREA AROUND AND UNDER THE PEDALS). THE LACK OF THIS GUARD MADE IT EASIER TO LOOK DOWN INTO THAT AREA; BUT LIKE I SAID BEFORE; ALL I COULD SEE WAS LOTS OF DUST AND DIRT. THERE WAS NO NOISE BEFORE; DURING OR AFTER THE INCIDENT. THERE WAS NO GRINDING NOTICEABLE. THE RUDDER INDICATION ON THE ECAM SCREEN SMOOTHLY FOLLOWED ALL RUDDER INPUTS. THE OUTBOUND CAPT OPENED THE E&E COMPARTMENT TO SEE IF HE COULD SEE ANYTHING FROM UNDERNEATH; AND HE; TOO; LOOKED FOR ANY FOREIGN OBJECTS AND COULD FIND NOTHING. I CALLED MAINT AND COORD WITH ZZZ1 OPS TO START THE BALL ROLLING FOR THE MECHANICAL DELAY AND MAINT PROB. I REALIZE THIS IS A FAIRLY COMPLEX ISSUE AND I HOPE TO HAVE GIVEN YOU ENOUGH INFO TO WORK WITH.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.