A B747-200 WAS DISPATCHED WITH A #1 ENG PYLON DRAIN COVER MISSING AND DEFERRED IMPROPERLY.

Narrative

ACFT ARRIVED IN XXX; ON FLT XXX ON JUN/XA/97. DURING THE ROUTINE WALKAROUND CHK IT WAS DISCOVERED THAT A NACELLE PANEL WAS MISSING FROM THE OUTBOARD SIDE. I WAS CONTACTED BY A MECH FROM ZZZ AND TOLD THAT A PANEL WAS MISSING; AND THAT THE CONFIGN DEV LIST ALLOWED THE PANEL TO BE MISSING ON A B747SP; BUT DID NOT INDICATE IT COULD BE MISSING ON A B747-222. I INFORMED THE MECH THAT THE PANEL COULD NOT BE MISSING IF THAT WAS THE WAY THE CONFIGN DEV LIST WAS WORDED; AND NEEDED TO INSTALL A PANEL IN THAT LOCATION. THE MECH TOLD ME THEY DID NOT HAVE THE PANEL IN STOCK; AND WHAT; IF ANYTHING; WERE HIS OPTIONS? I TOLD THE MECH TO MANUFACTURE A PANEL THAT WOULD FIT THE OPENING; AND TO APPLY SPD TAPE AROUND THE PANEL TO HOLD IT IN PLACE. IT WASN'T UNTIL AFTER THE ACFT HAD BEEN DISPATCHED; AND I REVIEWED THE DEFERRED ITEM; DID I FIND OUT THE PANEL WAS A NACELLE STRUT EMER DRAIN COVER. THIS PANEL IS DESIGNED IF THERE IS A CUT OR RUPTURE IN THE ENG FUEL SUPPLY LINE; IT ALLOWS FOR QUICK DRAINING OF THE PYLON. HAD I UNDERSTOOD THAT TO BE THE CASE; I WOULD HAVE REQUIRED ZZZ TO LOCATE A PANEL; POSSIBLY FROM ANOTHER AIRLINE; AND INSTALL THE CORRECT COVER PRIOR TO DEP. THE DEFERRED ITEM HAS BEEN ASSIGNED TO YYY AND MUST BE CORRECTED PRIOR TO FLT.