Narrative:

We were fueled, approximately 30 mins prior to departing the gate. I loaded the passenger and performed a walkaround, looking for any abnormalities such as flat tires, damaged surfaces, missing fuel caps, etc. I looked at each fuel tank (4) and it appeared all 4 caps were in place. I boarded the aircraft, gave passenger briefing and performed before start checklist. We started both engines and taxied from the gate. During the taxi check, my first officer checked the right wing for caps, and I checked left wing. During the taxi, the right outboard cap must have fallen off and onto the taxiway. We never noticed a missing cap and flew bos to rkd and rkd to bhb. No fuel siphoned out due to a flap inside the tank. The morning crew found the missing right outboard cap the next morning. The cap was found on the ramp in bos. I surmise the fueler did not lock the cap down after placing it on the tank. Because it was dark and the wing was higher, I could not tell it was not locked down. Because we always regularly have fuel orders wrong (more or less than we ordered or more in one side than the other) I always check for fuel caps in fear they might forget them. From now on I will have to climb on top of wing or up a ladder to verify the cap is secure. I have complained several times about the mistakes that commonly occur with our fuelers. So far, no significant change has occurred.

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Original NASA ASRS Text

Title: R OUTBOARD FUEL CAP FALLS FROM LTT WHILE TAXIING FOR TKOF.

Narrative: WE WERE FUELED, APPROX 30 MINS PRIOR TO DEPARTING THE GATE. I LOADED THE PAX AND PERFORMED A WALKAROUND, LOOKING FOR ANY ABNORMALITIES SUCH AS FLAT TIRES, DAMAGED SURFACES, MISSING FUEL CAPS, ETC. I LOOKED AT EACH FUEL TANK (4) AND IT APPEARED ALL 4 CAPS WERE IN PLACE. I BOARDED THE ACFT, GAVE PAX BRIEFING AND PERFORMED BEFORE START CHKLIST. WE STARTED BOTH ENGS AND TAXIED FROM THE GATE. DURING THE TAXI CHK, MY FO CHKED THE R WING FOR CAPS, AND I CHKED L WING. DURING THE TAXI, THE R OUTBOARD CAP MUST HAVE FALLEN OFF AND ONTO THE TXWY. WE NEVER NOTICED A MISSING CAP AND FLEW BOS TO RKD AND RKD TO BHB. NO FUEL SIPHONED OUT DUE TO A FLAP INSIDE THE TANK. THE MORNING CREW FOUND THE MISSING R OUTBOARD CAP THE NEXT MORNING. THE CAP WAS FOUND ON THE RAMP IN BOS. I SURMISE THE FUELER DID NOT LOCK THE CAP DOWN AFTER PLACING IT ON THE TANK. BECAUSE IT WAS DARK AND THE WING WAS HIGHER, I COULD NOT TELL IT WAS NOT LOCKED DOWN. BECAUSE WE ALWAYS REGULARLY HAVE FUEL ORDERS WRONG (MORE OR LESS THAN WE ORDERED OR MORE IN ONE SIDE THAN THE OTHER) I ALWAYS CHK FOR FUEL CAPS IN FEAR THEY MIGHT FORGET THEM. FROM NOW ON I WILL HAVE TO CLB ON TOP OF WING OR UP A LADDER TO VERIFY THE CAP IS SECURE. I HAVE COMPLAINED SEVERAL TIMES ABOUT THE MISTAKES THAT COMMONLY OCCUR WITH OUR FUELERS. SO FAR, NO SIGNIFICANT CHANGE HAS OCCURRED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.