What was found
STRUT PRESSURE RELIEF DOOR 433AL FOUND MISSING ON PERFORMING ETOPS PRE DEPARTURE SERVICE CHECK. ACCOMPLISHED INSPECTION IAW AMM 05-51-59-211-801. NO DAMAGE NOTED AROUND MISSING DOOR OR AROUND ACFT. MISSING PANEL IS IDENTIFIED AS A PRESSURE RELIEF DOOR. ONE PRESSURE RELIEF DOOR MISSING IS PERMISSIBLE IAW CDL 54B. INSTALLED NEW LEFT PRESSURE RELIEF DOOR PANEL #433AL ON #1 ENG OUTBOARD PYLON REF AMM 54-53-01-400-801-002.