Narrative:

#6 leading edge device (slat) deployed to full extended position. In sum: an air carrier large transport freighter crew was informed at the hotel that maintenance was being performed on the #6 slat actuator. The replacement actuator would not mount properly, so the original one was repaired using parts from the replacement. A fairing was broken by the actuator. This was written off by a cdl entry. An electrical switch was also changed, the hydraulic system svced, and the aircraft readied for flight. Flap retraction was normal when airborne on both legs. When cruise speed was attained at FL330, the aircraft rolled to the right with a right yaw. The so's auxiliary panel showed that the #6 leading edge device (slat) had deployed. There were no indications on the pilot's forward panel. Control checks were made and the aircraft returned to its departure station. The landing was uneventful with 30 flaps. Full control input was required at high speeds (300 KTS). This incident occurred on the second leg after maintenance. The maintenance work was performed at smf. The aircraft flew small transport to sfo with no problems, then returned to sfo after the control problem. An emergency was declared.

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Original NASA ASRS Text

Title: AN ACR LGT FREIGHTER CREW DECLARED AN EMER WHEN IT HAD A FLT CTL PROB.

Narrative: #6 LEADING EDGE DEVICE (SLAT) DEPLOYED TO FULL EXTENDED POS. IN SUM: AN ACR LGT FREIGHTER CREW WAS INFORMED AT THE HOTEL THAT MAINT WAS BEING PERFORMED ON THE #6 SLAT ACTUATOR. THE REPLACEMENT ACTUATOR WOULD NOT MOUNT PROPERLY, SO THE ORIGINAL ONE WAS REPAIRED USING PARTS FROM THE REPLACEMENT. A FAIRING WAS BROKEN BY THE ACTUATOR. THIS WAS WRITTEN OFF BY A CDL ENTRY. AN ELECTRICAL SWITCH WAS ALSO CHANGED, THE HYD SYS SVCED, AND THE ACFT READIED FOR FLT. FLAP RETRACTION WAS NORMAL WHEN AIRBORNE ON BOTH LEGS. WHEN CRUISE SPD WAS ATTAINED AT FL330, THE ACFT ROLLED TO THE R WITH A R YAW. THE SO'S AUX PANEL SHOWED THAT THE #6 LEADING EDGE DEVICE (SLAT) HAD DEPLOYED. THERE WERE NO INDICATIONS ON THE PLT'S FORWARD PANEL. CTL CHKS WERE MADE AND THE ACFT RETURNED TO ITS DEP STATION. THE LNDG WAS UNEVENTFUL WITH 30 FLAPS. FULL CTL INPUT WAS REQUIRED AT HIGH SPDS (300 KTS). THIS INCIDENT OCCURRED ON THE SECOND LEG AFTER MAINT. THE MAINT WORK WAS PERFORMED AT SMF. THE ACFT FLEW SMT TO SFO WITH NO PROBS, THEN RETURNED TO SFO AFTER THE CTL PROB. AN EMER WAS DECLARED.

Data retrieved from NASA's ASRS site as of July 2007 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.