What was found
FLIGHT CREW REPORTED SERVICING DOOR MISSING DURING POST FLIGHT INSPECTION. UPON INVESTIGATION, IT WAS DISCOVERED THAT APU OIL WAS SERVICED PRIOR TO THE FLIGHT. MECHANIC CONFIRMED THAT THE DOOR WAS LATCHED AND SECURE PRIOR TO FLIGHT. INVESTIGATION REVEALED THAT OTHER EMB 145 OPERATORS HAVE MODIFIED THIS DOOR THROUGH THEIR ENGINEERING PROCESS TO ADD ADDITIONAL FASTENERS DUE TO LOSS OF THE DOORS DURING FLT WHEN SUCH LOSSES CANNOT BE ATTRIBUTED TO MAINT ERROR. THE DOOR AND LATCH DESIGN DO NOT APPEAR TO BE TOLERANT TO NORMAL MECHANICAL & HUMAN VARIANCE. IN PARTICULAR, THE UPPER MOST FORWARD LATCH APPEARS TO BE MORE CRITICAL THAN THE OTHER LATCHES AND IS OF A DESIGN WHICH IS NOT TOLERANT OF NORMAL WEAR.