What was found
DURING DESCENT FROM FL350 TO FL290, RECEIVED A TANK 3 TIP TRAPPED LEVEL 1 ALERT, WITH ASSOCIATED 5800 LBS UNUSABLE AND A TANK 3 PUMPS OFF ALERTS. PASSING 8000 FT, TRAPPED ALERT WENT AWAY, BUT THE NR 2 TANK KEPT FEEDING NR 3. INSPECTED TIP TANK TRANSFER SYSTEM AND FOUND THE NR 3 MAIN TANK OTBD TRANSFER FLOAT VALVE BROKEN AND INBD TRANSFER FLOAT VALVE STICKING. REMOVED AND REPLACED BOTH TRANSFER FLOAT VALVES. LEAK AND OPS CHECKED GOOD IAW FIM 28-14-04, TASK 28-14-00-810-803. AMM 28-00-00-2, AND AMM 28-21-10-2.