What was found
CREW REPORTED SMELL OF FUEL IN AFT CABIN AT ALTITUDES OF 2500 FT AND BELOW IN LEVEL FLIGHT. IT WAS ALSO NOTICEABLE ON GROUND. IT WAS LESS NOTICEABLE AT HIGHER ALTITUDES AND UNDER PRESSURIZATION. MAINT LOCATED SOURCE OF SMELL. FWD WING CENTERLINE SPLICE PLATE (PN 602240111) WAS SEEPING FUEL PAST RIVETS. SPLICE IS LOCATED JUST AFT OF CABIN PRESS POPPET VALVES, WHICH ARE FOUND AT END OF CABIN AISLE WALKWAY. WHEN AC WAS AT ALTITUDE, POPPET VALVES WERE HELD CLOSED BY CABIN PRESSURE, BUT AS AC DESCENDED (2500 FT AND BELOW) CABIN PRESSURE DECREASED ALLOWING POPPET VALVES TO OPEN AND PERMIT JET FUEL FUMES TO ENTER CABIN. TECH RECOMMENDS TO DEMATE WING FROM FUSELAGE, REPAIR LEAKS AND REMATE WING. AC IN REPAIR.