What was found
FLT 106, IAD TO LGB, A/C DEVELOPED FUEL MIGRATION FROM LEFT MAIN TO CTR TANK. LEVELED OFF AT FL280, DID AN EMERGENCY LANDING AT PITTSBURG. A/C TOUCHDOWN V/S WAS LESS THAN 100 FPM. FOUND OVERPRESSURE PROTECTOR 96QM SEAL CRACKED ON VALVE. REPLACED OVERPRESSURE PROTECTOR 96QM REF AMM 28-12-41, INSP CK PER 28-12-47, LEAK CHECK TANK PLATES 147AZ AND 548AB REF AMM 57-17-11 OK.