Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
General Maintenance Action
Aircraft
Shortly after reaching our cruising altitude; the Captain noticed an imbalance between the main tanks and he corrected the situation. About 30 minutes later; we noticed we were using more fuel out of main tank 1; creating an imbalance between the main tanks again. When we rechecked the fuel burn; we noticed we over-burned our fuel by 800-1;000 LBS. The captain (PM) contacted Maintenance and the Flight Operations Duty Officer (FODO) to determine if our issue was due to faulty gauges or an actual fuel leak. We could not confirm the actual fuel leak and we all agreed it was the best option to continue on to our destination with [nearby airports] as alternates. We landed uneventfully with 5;300 LBS of fuel. When we taxied onto the gate; one of our mechanics signaled us to shut the engines. The mechanic informed us there was a visible fuel leak from the number one engine. We deplaned without incident and later continued on in a new aircraft.
B737-800 FO reported that after an abnormal inflight fuel burn the Mechanic on the ground at the gate noticed a visible fuel leak.