A B747-200 DURING REPLACEMENT OF THE L INBOARD LNDG LIGHT LAMP THE LEADING EDGE DEVICES WERE RETRACTED INCURRING SERIOUS INJURY TO THE TECHNICIAN.

Narrative

UPON ARR AT ZZZ; CAPT ABC AND FO WXWX LEFT THE ACFT TO FILE THEIR FLT PLAN AT BASE OPS. I REMAINED ON BOARD TO CONDUCT MY PREFLT DUTIES. WHILE IN THE COCKPIT IN THE FE SEAT; AN ACR MAINT EMPLOYEE ZXZX CAME INTO THE COCKPIT AND REQUESTED THAT I LOWER THE LEADING EDGE FLAP TO ALLOW MAINT TO CHANGE A LNDG LIGHT. I LOWERED THE FLAP BY ELECTRICAL SYS. I MOVED THE FLAP ARM SWITCH TO 'ARM' POS AND ALL DIRECTIONAL SWITCHES TO DOWN POS. THE LEADING EDGE FLAP GREEN LIGHT ILLUMINATED INDICATING THAT ALL LEADING EDGE FLAPS WERE EXTENDED. ZXZX LEFT THE COCKPIT AND I RESUMED MY PREFLT DUTIES. A SHORT TIME LATER; XYXY CAME INTO THE COCKPIT AND STARTED ADP AND MOVED FLAP LEVER TO 10 DEG POS. I LEFT THE COCKPIT AND WENT OUTSIDE TO OBSERVE WHAT TRANSPIRED. I LATER LEARNED THAT ZXZX HAD BEEN INJURED WHILE CHANGING THE LNDG LIGHT. SUPPLEMENTAL INFO FROM ACN 454540: AFTER OPERATING AS FE ON ACR FLT XYZ FRA-ZZZ; I WAS RESTING IN THE UPPER DECK CABIN DURING THE GND TIME BEFORE DEP. AT OR ABOUT XF00Z; SOMEONE CAME RUNNING UP THE STAIRS YELLING; 'LOWER THE SLATS; HE'S CAUGHT IN THE SLATS.' I IMMEDIATELY PROCEEDED INTO THE COCKPIT. I IMMEDIATELY PLACED THE FLAP HANDLE TO THE 10 DEG POS AND TURNED ON THE ADP'S ON. I DO NOT RECALL IF I TURNED THE APU BLEED ON OR IF IT WAS ALREADY ON. I LATER LEARNED MECH ZXZX WAS SERIOUSLY INJURED.