DC10 ACFT IN CRUISE WHEN PAX POINTED OUT AN OIL FILLER COVER DOOR THAT WAS OPEN. FAA INSPECTOR MET THE FLT TO INSPECT THE DOOR.

Narrative

ABOUT THE TIME WE LEVELED OFF; A FLT ATTENDANT INFORMED THE FLC THAT A PAX HAD NOTICED THE #1 OIL FILLER COVER DOOR (NOT THE OIL CAP) WAS OPEN AND WAS CONCERNED. FLC INSPECTED AND CONFIRMED THE DOOR WAS OPEN. I ASSURED SAID PAX THAT THERE WAS NO DANGER INVOLVED. I THANKED HIM FOR BEING AN OBSERVANT PAX AND INFORMING US ABOUT IT. I SHOOK HIS HAND AND BOUGHT HIM A MOVIE HEADSET. WE MONITORED OIL PRESSURE CLOSELY FOR THE REMAINDER OF THE FLT. THERE WAS NO VISIBLE EVIDENCE OF OIL LOSS. IN THE ACFT LOGBOOK WE RPTED THAT THE DOOR HAD OPENED ENRTE FOR MAINT FOLLOW-UP. WHEN WE ARRIVED AT THE GATE; WE WERE MET ON THE RAMP BY THE FAA WHO IMMEDIATELY INSPECTED THE OIL FILLER COVER DOOR. THIS SEEMED TO BE AN UNUSUAL COINCIDENCE AND RAISED THE QUESTION AS TO WHETHER THE FAA HAD BEEN CONTACTED WHILE WE WERE STILL IN THE AIR. THIS PARTICULAR ACFT HAD NO TELEPHONES ON BOARD. THUS IF ANY PHONE CALL HAD BEEN MADE; IT WOULD HAVE HAD TO HAVE BEEN MADE FROM A PAX'S CELLULAR PHONE. USE OF A CELLULAR PHONE IS AGAINST REG AND IS ALSO A SAFETY ISSUE. ALTHOUGH WE DO NOT KNOW IF SUCH A PHONE CALL WAS MADE IN THIS SIT; IT DOES RAISE THE SAFETY CONCERN AS TO WHETHER PAX WILL REFRAIN FROM USING CELLULAR PHONES AS INSTRUCTED.