ACFT EXPERIENCES A ROLL ON FINAL DUE TO AN ASYMMETRIC FLAP SIT AS FINAL FLAPS ARE EXTENDED.

Narrative

WHILE THE FO (PF) WAS FLYING AN MLG ON FINAL APCH INTO LAX-24L; THE CAPT (PNF) ON COMMAND BY THE PF; MOVED FLAPS FROM 25 DEGS TO 30 DEGS (THE FINAL SETTING). THE ACFT DEVELOPED AN UNCOMMANDED L ROLLING MOVEMENT WHICH REQUIRED 1/2 AILERON CTL DEFLECTION THE R BY THE PF TO COUNTER THE ACFT'S SUDDEN AND PERSISTENT ROLLING MOVEMENT. THE PF COUNTERED THE ROLLING MOVEMENT BEFORE THE ACFT REACHED A 10 DEG BANK ANGLE AND CONTINUED TO FLY THE VISUAL APCH WINGS LEVEL WITH 1/2 CTL YOKE AILERON INPUT TO THE R. WITHIN A FIVE SECOND SPAN AFTER THE UNCOMMANDED L ROLL; THE PF ASKED THE PNF TO CHK FUEL BAL; LEADING EDGE DEVICES; FLAP INDICATIONS; SPDBRAKES; AND ALL ASSOCIATED GREEN OR POSSIBLE AMBER LIGHTS. ALL LIGHTS AND INDICATIONS DISPLAYED GREEN AND NORMAL RESPECTIVELY. ALL INDICATIONS WERE NORMAL WITH AN UNCOMMANDED L ROLLING MOTION. AT THIS POINT; ABOUT 600 FT AGL; THE FO TRANSFERRED THE FLT CTLS TO THE CAPT SO HE; THE CAPT; COULD GET A BETTER FEEL FOR WHAT THE ACFT WAS DOING. THE CAPT; NOW THE PF; CONFIRMED THAT THE ACFT WAS CTLABLE IN ITS PRESENT CONFIGN; (I.E.; GEAR DOWN; FLAPS 30 DEGS; ENGS SPOOLED; ON GS; ON TARGET SPD -- 127 KTS; WITH 1/2 AILERON CTL TO THE R) AND THE BEST COURSE OF ACTION WAS TO LAND THE ACFT; WHICH HE DID WITHOUT INCIDENT. AFTER LNDG SAFELY; WE LEFT THE ACFT IN LNDG CONFIGN FOR MAINT INSPECTION AT THE GATE (I.E.; FLAPS 30 DEGS; SPDBRAKE ARMED). WE WERE UNABLE TO GET MUCH INFO FROM THE LINE MAINT CREW BEFORE DEADHEADING BACK TO SFO. THIS PARTICULAR ACFT HAD A HISTORY OF TRAILING EDGE AND LEADING EDGE DEVICE PROBS. DURING OUR BRIEFING PRIOR TO THIS FLT (INCIDENT); THE CAPT NOTED AND BRIEFED 3 PREVIOUS MAINT WRITE-UPS INDICATING A CHRONIC PROB WITH BOTH LEADING EDGE AND TRAILING EDGE DEVICES (I.E.; POPPED CIRCUIT BREAKERS; SPLIT FLAPS ON FINAL APCH) WHICH OCCURRED 2 DAYS PRIOR TO OUR FLT ON JUL/MON/93. MAINT ACTION WAS INDICATED FOR EACH OF THE 3 WRITE-UPS FOLLOWED BY APPROPRIATE GND CHKS WHICH CHKED OUT 'OK' ON JUL/93.