What was found
(B-18707) FUEL SPILL FROM RT WING SURGE TANK VENT PORT DURING REFUELING. FUEL TRANSFERRED & RT SURGE TANK DRAINED. AFTER THE ACFT RETURNED PERFORMED RT WING TANK VTO FUNCTIONAL TEST AND FND: - FUEL SPILLED INTO RT SURGE TANK BEFORE FILLED NR 4 MAIN TANK TO VTO. ( NR 4 TANK = 28200 LBS) - OVERFILL PROTECTION WAS TRIGGERED BY RT WING SURGE TANK FLOAT SW. 2. REPLACED NR 4 MAIN TANK VENT FLOAT VALVE (WS 1162) 3. PERFORMED EACH RT WING TANK VTO FUNCTIONAL TEST CK NORMAL WITHOUT ANY OVERFILL CONDITION.