WDB OPERATED WITH MISSING FUSELAGE PANEL.

Narrative

I ACCOMPLISHED WALKAROUND. APPARENTLY I MISSED SEEING A MISSING PANEL ON ACFT. PANEL LOCATION AFT L HAND SIDE OF ACFT NEAR APU INLETS. ACFT A LOCKHEED L1011. UNEVENTFUL FLT TO BOSTON. ON WALKAROUND AT BOSTON; I FOUND PANEL WAS MISSING. INVESTIGATION BY COMPANY DETERMINED PANEL WAS NEVER REINSTALLED BY MAINT AFTER WORK ON TAILSKID. CONTRIBUTING FACTORS: L1011 TAIL STICKS OUT INTO ROAD USED BY BAGGAGE CARTS; CATERING AND FUEL TRUCKS; ETC. IF I WALK AROUND ACFT TO VERY BACK OF ACFT; PROBABILITY OF GETTING HIT IS GREAT. ACFT APU WAS ON. EXHAUST DIRECTED DOWN; IMPEDING WALKAROUND DUTIES. COMMON RESULT WALK UNDER TAIL AND ENG ABOUT 10 FT FROM END. FLUID LEAKS FROM #2 ENG. I DIDN'T WANT TO GET THIS FLUID IN MY EYES; SO I SCANNED R HAND SIDE OF TAIL AND ENG; WALKED UNDERNEATH; THEN SCANNED L HAND SIDE OF ENG. I WAS VERY CLOSE TO THE SIDE OF THE ACFT. THE MISSING PANEL IS AFT OF THE POINT WHERE THE ACFT SKIN TAPERS TOWARDS ACFT CTR. MY POS DID NOT ENABLE ME TO SEE THE APPROX 8 INCH BY 8 INCH HOLE WHERE THE PANEL SHOULD HAVE BEEN. I PROCEEDED FORWARD; THEN SCANNED THE L HAND HORIZ STABILIZER AND TAIL SECTION. AGAIN; MY PROX TO THE ACFT SIDE PREVENTED ME FROM SEEING THE HOLE. ACFT DESIGN; THE PANEL IN QUESTION IS VERY CLOSE TO 2 APU INLETS WHICH ARE COVERED BY DARK SCREENS. IT'S EASY TO ASSOCIATE THE MISSING PANEL HOLE WITH THESE INLETS. PREVENTION: IF I HAD MOVED AWAY FROM ACFT; MY POINT-OF-VIEW WOULD HAVE ALLOWED ME TO SEE THE HOLE. ENSURE ON WALKAROUNDS THAT ALL PARTS OF THE ACFT VISIBLE FROM THE GND CAN BE SEEN SQUARE ON.