What was found
LEFT ENGINE OIL ACCESS DOOR (APPROXMATELY 6 INCHES BY 8 INCHES) DEPARTED THE AIRCRAFT STRIKING THE LT HORIZONTAL STABILIZER, CUTTING A SMALL HOLE IN THE DEICE BOOT AND DENTING THE LEADING EDGE SKIN. INSPECTION OF THE HINGE REMAINING ON THE COWLING REVEALED THAT HINGE PIN WORKED ITS WAY FORWARD FROM THE HINGE DUE TO WEAR IN THE HINGE. AFTER THE HINGE PIN WORKED FORWARD, THE OIL DOOR FELL OFF. INSPECTION OF THE RT OIL ACCESS DOOR REVEALED A SIMILAR WORN HINGE. THE NEW DOOR ASSY (PN 5552150-37) HAS AN IMPROVED HINGE. RT DOOR HINGE WAS REPLACED.