A BE02 COMMUTER FLC EXPERIENCED JAMMED CTLS DURING FULL FLAP EXTENSION ON APCH INTO SEA. THE FO PF KEPT THE ACFT FROM CONTINUING TO ROLL BY EXERTING CTL COLUMN FORCE AND USING OPPOSITE RUDDER. THE YOKE REMAINED STUCK AND THE FO LANDED THE ACFT BY COMPENSATING WITH OTHER CTLS.

Narrative

CLRED TO LAND ON RWY 16L AT SEATAC ARPT. THE GEAR WAS DOWN AND FLAPS WERE 17 DEGS. I CALLED FOR FLAPS 35 DEGS AND SUDDENLY THE ACFT ABRUPTLY ROLLED TO THE R. I COUNTERED WITH OPPOSITE AILERON. WHILE DOING SO; THERE WAS A CTL SURFACE JAMMING. WHILE CORRECTING THE JAM; I THREW THE FLAP; KEEPING THE ACFT WINGS LEVEL AND LANDED WITHOUT FURTHER INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE FLAP JACK SCREW HAD PUSHED THE OUTBOARD FLAP OFF ITS INBOARD ROLLER AND INTO THE AILERON. WHEN THIS HAPPENED THE CREW THOUGHT THAT THEY HAD A SPLIT FLAP CONDITION BECAUSE THE ACFT ROLLED ABRUPTLY TO THE R DURING FLAP EXTENSION. WHEN THIS RPTR TRIED TO CORRECT THE SURFACES FELT JAMMED; AND HE POPPED THROUGH SOMETHING WHILE LEVELING THE ACFT. THIS RPTR STATES THAT HE IS MUSCULAR AND YET WAS NOT ABLE TO OVERRIDE THE JAM COMPLETELY. THE YOKE WAS STUCK AT A 9-10 O'CLOCK POS AND THIS RPTR USED FULL OPPOSITE RUDDER TO COUNTERACT THE AILERON'S FORCE. FOR ALL PRACTICAL PURPOSES; THIS ACFT WAS LANDED IN A SLIP. AS A SIDENOTE; THIS INCIDENT WAS ALSO RPTED TO THE NTSB PER THE INITIAL NOTIFICATION RULE.