What was found
ACFT HAS FACTORY INSTALLED EXTENDED RANGE FUEL CELLS. CELLS ARE SEALED, WING BAYS OR "WET WING" FUEL CELLS LOCATED IN EACH WING TIP. WING TIP FUEL CELLS WERE FOUND LEAKING FUEL THROUGH FUEL VENT TUBES ON BOTH SIDES. CAUSE OF THE LEAK WAS FOUND TO BE DETERIORATION OF SEALANT AROUND TUBE SLIP JOINT FITTINGS. FUEL CELLS HAD AN EXCESSIVE AMMOUNT OF PARTICULATE CONTAMINATION. CONTAMINATION IS DUE TO THE DETERIORATION OF FUEL TANK SEALANT. THE PARTICLES OF DETERIORATED SEALANT WERE TRAPPED IN MULTIPLE LOCATIONS THROUGHOUT ENTIRE FUEL STORAGE SYS. UPPER WING SKIN MUST BE REMOVED TO ACCESS FUEL CELL DUE TO INADEQUATE INSPECTION PANEL LOCATIONS.