Narrative:

Misfueling at home base by inexperienced line crew. Fueling was being supervised by both members of the flight crew, who did not notice they were fueling from the jet truck instead of the gas truck.

Google
 

Original NASA ASRS Text

Title: GND PERSONNEL FUELED RECIPROCAL ENGINE ACFT WITH JET FUEL.

Narrative: MISFUELING AT HOME BASE BY INEXPERIENCED LINE CREW. FUELING WAS BEING SUPERVISED BY BOTH MEMBERS OF THE FLT CREW, WHO DID NOT NOTICE THEY WERE FUELING FROM THE JET TRUCK INSTEAD OF THE GAS TRUCK.

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.