ACFT ROLLED SHARPLY TO THE LEFT ON FINAL APCH TO COS.

Narrative

AFTER SELECTION OF FULL LNDG FLAPS (30 DEGS); THE LGT ROLLED TO LEFT REQUIRING FULL AILERON DEFLECTION TO RIGHT; RIGHT RUDDER INPUTS TO MAINTAIN LEVEL FLT. IMMEDIATELY; WE RETRACTED THE FLAPS TO THEIR NEXT POS OF 25 DEGS. SOME CTL WAS REGAINED. OUR COMPANY PROCS CALL FOR EVALUATION OF FLAPS JAMMED/ASYMMETRY AND LEADING EDGE DEVICE PROBS. NONE OF THESE PROBS WERE APPARENT. THE ENGINEER MADE A VISUAL INSPECTION FROM THE CABIN AND NO ABNORMAL SPOILER FLOAT OR AILERON PROB COULD BE FOUND OR DETERMINED. SINCE CONTROL WAS ADEQUATE FOR A SAFE LNDG; WE DECIDED NOT TO PURSUE THE PROB ANY FURTHER. AN UNEVENTFUL LNDG WAS MADE. FIRE AND CRASH EQUIP WERE STANDING BY. ONE OTHER PROC THAT WAS DISCUSSED WAS A PROC IN WHICH 5 DEG FLAPS ARE USED IN LNDG IF THERE COULD BE A SPOILER FLOAT PROB. HOWEVER; OUR NEAR MAX LNDG WT AND HIGH ARPT ELEVATION CONSIDERED; WE DECIDED TO LAND THE ACFT IN THE CONFIGN IT WAS IN AND ELIMINATE THE RISK OF COMPROMISING CTL INSTEAD OF INCREASING IT. UPON MAINT INSPECTION; A BROKEN #2 SPOILER ACTUATOR WAS DETERMINED TO BE THE CAUSE. WE WERE INFORMED BY MAINT THAT HAD WE RETRACTED THE FLAPS; IT WOULD HAVE CAUSED SUBSTANTIAL DAMAGE TO THE #1 FLAP AND #1; 2; 3 SPOILERS. UPON LNDG; THE SPOILERS WERE DEPLOYED AND JAMMED IN THE FULL UP POS. INFLT; HAD WE PULLED THE SPOILER HANDLE SLIGHTLY TO DETERMINE A SPOILER FLOAT (AS IS COMMON PRACTICE) WE MIGHT HAVE BIT OFF MORE THAN THE LGT COULD CHEW. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: WHEN THE FLAPS WERE RETRACTED TO 25 DEGS; THE SPOILER FLOAT WAS NOT NOTICEABLE. THE FLAPS WERE NEVER RE-EXTENDED TO 30 DEGS. THE CAPT DECIDED THAT THINGS WERE WELL UNDER CONTROL WITH THE FLAPS AT 25 DEGS AND HE DECIDED NOT TO DO ANY MORE EXPERIMENTING FOR FEAR OF DAMAGE. THIS PROVED TO BE A WISE DECISION. THE ACFT FLEW A LARGE 360 DEG TURN DURING THE TROUBLESHOOTING.