FOUR MECHANICS REPORT ON THE EVENTS SURROUNDING DAMAGE TO A B737-300 ACFT RIGHT WING OUTBOARD FLAP; OUTBOARD EDGE WITH THE AILERON TAB DURING RIGGING PROCEDURES; FOLLOWING REPLACEMENT OF FLAP TRANSMISSIONS 2; 5 AND 8.

Narrative

UPON COMPLETION OF THE INSTALLATION OF THE #5 TRANSMISSION; THE CREW BEGAN THE RIGGING PROCESS. AFTER ATTACHING THE TORQUE TUBES ON THE L WING; I WENT TO THE FRONT OF THE ACFT AND PROCEEDED TO THE FLT DECK. ANOTHER CO-WORKER CAME AND GAVE THE CLR AND FLAPS UP COMMAND. ONCE THE FLAPS CAME TO FULL 0 DEGS; I WAITED A FEW MOMENTS AND MOVED FLAPS TO FULL 40 DEGS. A FEW MOMENTS INTO THE SEQUENCE; A CO-WORKER CAME TO THE DOOR AND TOLD ME TO STOP THE FLAPS. A QUICKLY SHUT OFF THE HYDS. SUPPLEMENTAL INFO FROM ACN 786323: PERSON 3 AND MYSELF (PERSON 2) WERE PUT ON ACFT TO REMOVE AND REPLACE #2 AND #8 FLAP TRANSMISSIONS. #2 AND #8 WERE REPLACED AND A PARTS TAG WAS FILLED OUT WITH WRITE-UPS THAT TORQUE TUBES ON THE INBOARD AND OUTBOARD SIDE OF #2 TRANSMISSIONS WERE DISCONNECTED AND A WRITE-UP THAT #8 TRANSMISSION TORQUE TUBE WAS DISCONNECTED. I WAS ON THE L WING WHEN PERSON 3 CAME OVER AND LOOKED TO MAKE SURE THAT ALL WAS GOOD ON THE L SIDE. I ASKED HIM IF ALL WAS GOOD ON THE R SIDE AND HE SAID 'YES.' PERSON 1 WENT TO THE COCKPIT TO RUN THE FLAPS. SUPPLEMENTAL INFO FROM ACN 786324: WE COMPLETED THE R&R OF THE #5 TRANSMISSION. AT THAT TIME; 4 OR 5 OF OUR CREW CAME OVER TO ASSIST IN THE RIG OF THE FLAPS (TRAILING). TO DO THIS; WE MOVE THE FLAPS UP AND DOWN A FEW CYCLES TO HEAT UP THE HYD FLUID AND SOAK THE FLAPS FOR A COUPLE MINS. I WAS ON THE L WING TO CLR IT. THE POS WAS FULL DOWN WHEN WE STARTED IT. AS THE FLAPS MOVED UP; THERE WAS NO EVENT. HOWEVER; WHEN THE FLAPS STARTED TO COME DOWN; I HEARD SOMEONE SAY SOMETHING AND I WENT OVER TO THE R WING; NOTICED THE FOILS MID FLAPS WERE DIGGING INTO THE OUTBOARD FIXED PORTION OF THE WING. AS NOTICED THE TORQUE TUBE HAD NOT BEEN ATTACHED TO #8 TRANSMISSION. I WONDERED; HOWEVER; HOW #2 TRANSMISSION WAS ATTACHED AND NOT #8 TRANSMISSION. I THINK THERE WAS TOO MANY PEOPLE ALL DOING SOMETHING DIFFERENT AT THE SAME TIME. SUPPLEMENTAL INFO FROM ACN 786325: I WENT TO ASSIST. I ASKED IF ALL THE TORQUE TUBES WERE CONNECTED; TOOLS REMOVED FROM THE FLAP WELL AND IF THE CANNON PLUG WAS CONNECTED IN THE WHEEL WELL. THEY ANSWERED YES. WE DISCUSSED WHAT WAS GOING TO HAPPEN NEXT: CYCLE FLAPS 2 TIMES AND LEAVE IN THE UP POS; THEN CHK UP-STOPS. THE FLAPS WENT FULL UP AND BEGAN TO COME BACK DOWN. I HEARD A SLIGHT POP AND CRUNCHING NOISE. NOTICED THE R OUTBOARD FLAP WEDGED AT AN ANGLE AND NOTICED DAMAGE TO THE OUTBOARD EDGE AND AILERON TAB.