A320 FLT CREW EXPERIENCES FIRM TOUCHDOWN WHEN ACFT FAILS TO RESPOND TO SIDE STICK CTLR INPUTS IN THE FLARE. PF SUGGESTS ACFT MAY HAVE BEEN HEAVIER THAN PROGRAMMED.

Narrative

NORMAL OPS ON FLT ZZZ1 TO ZZZ. I FLEW AN ILS APCH AND TOOK OVER VISUALLY AT 1000 FT AGL. THE AUTOPLT WAS DISENGAGED AT 600 FT AGL AND HAND FLOWN THROUGH THE LNDG. THE ACFT WAS STABLE; ON AIRSPD; NORMAL DSCNT PARAMETERS THROUGHOUT THE APCH. AT 30 FT AGL THE THROTTLES WERE SLOWLY PULLED TO IDLE AND I PUT IN AFT CTL STICK TO START THE FLARE. AT 20 FT AGL; I NOTICED THE PITCH NOT INCREASING AND INPUT MORE BACK PRESSURE TO THE CTL STICK. THE PITCH DID NOT INCREASE AND I IMMEDIATELY PULLED ON THE CTL STICK TO ABOUT 80-90% OF ITS TRAVEL; I DID NOT HIT THE AFT LIMIT. ACFT DID RESPOND; INCREASING THE PITCH RIGHT AT TOUCHDOWN TO ABOUT 6 DEGS. TOUCHDOWN WAS VERY FIRM WITH NO BOUNCE. THE ROLLOUT WAS NORMAL AND WE TAXIED TO GATE. I WAS SURPRISED BY THE LACK OF RESPONSE TO THE INPUTS IN PITCH. THE ACFT REACTED AS IF THE COMPUTED SPD BEING FLOWN WAS LOW OR INADEQUATE; SLUGGISH RESPONSE TO NORMAL INPUTS. THE SLOW PITCH RESPONSE BY THE ACFT CAUSED THE SLOW AND LATE FLARE RESULTING IN THE FIRM TOUCHDOWN. THE SLUGGISH RESPONSE OF THE ACFT IN PITCH SURPRISED ME. THE LARGE INPUT AT THE END OF THE FLARE COULD HAVE BEEN INDUCED SOONER. MAYBE FLYING IN FLAPS 3 DEGS WOULD HAVE INCREASED THE SPD TO HELP THE PITCH; BUT THE WET AND SHORTER RWY; I OPTED FOR FULL FLAPS. THE ACFT RESPONDED AS IF IT WAS FLYING TOO SLOW; WAS THE COMPUTED SPD CORRECT? SHOULD WE BE CHKING THE COMPUTED WTS AND SPDS FOR APCH AND LNDG. I HAVE NOTED THIS SLOWNESS IN PITCH BEFORE; IN THE A320 MODEL; BUT THE RESULTS WERE NEVER OVER A LIMIT -- JUST A FIRMER THAN EXPECTED TOUCHDOWN.