What was found
AIRCRAFT WAS NOT GROUNDED: AN EMERGENCY WAS DECLARED INTO PHL DUE TO THE FLIGHT CREW REPORTING THAT THE RIGHT FUEL OUTER TANK WAS INDICATING GREEN (OPEN. POSITION) BUT FUEL WAS NEVER TRANSFERRED TO THE INNER TANK TILL FINAL AT 20 00 FEET. THE LEFT TRANSFERRED NORMALLY. THE AIRCRAFT LANDED SAFELY AT PHL WITHOUT FURTHER INCIDENT. MAINTENANCE REPORTED THAT PREVIOUS LEGS HAD MULTIPLE FAULTS FOR THE FUEL LEVEL SENSING CONTROL UNIT (9QJ) MAINTENANCE REPLACED THE FUEL LEVEL SENSING CONTROL UNIT (9QJ) AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 28-46-34.