Date: 201302
Local time of day: 0601-1200
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Climb
ATC / advisory: Center ZZZZ
Aircraft component: Fuel System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Attendant
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: First Officer did walk around when we got to aircraft. No problems. Near departure time smelled fuel. Upon investigation we found out there had been a fuel spill and even with the aircraft not being fueled; there was fuel spilling out of the NACA fuel vent under the right wing. I had the aircraft de-boarded and turned off the air conditioning packs. The problem was written up in the logbook and Maintenance eventually fixed the problem. It was explained to me there was a faulty valve that didn't close and that he got it to close and the leak stopped. The fuel leaking prior was residual and there was just fuel under the wing and on the ramp. The fire department sprayed the wing and the spill on the ground; after they mopped up what they could. We boarded got a new release and left. The fuel was 8.51 in left tank 15.7 or so in the center and 8.71 in the right. After takeoff climbing through 10;000 FT I got a call from the Flight Attendant at the rear of the aircraft telling me that we had a spray off the right wing about 5 inches in diameter near the wing and winglet area. It was night and the white wing Nav light lit it up. Upon further discussion; I determined this was not a vortex from humid air as the other wing was not the same. The suspected fuel did not dissipate only became a smaller diameter when we sped up. No checklist in the QRH applied to a suspected wing fuel leak; only an engine fuel leak. We elected to return for landing and declared an emergency. Unfortunately I used the term 'I am declaring an emergency' rather than ICAO 'Mayday Mayday Mayday.' There was some confusion about the nature of our emergency and the request for ARFF to follow the aircraft and assess the leak. We landed and returned to a hardstand area; ARFF followed to hardstand saw no fuel leaking. The fuel was 8.51 in left 12.0 or so in the center and 8.71 in the right. I was concerned about faulty valves in wrong positions; why did the right tank not decrease if it was over full or some fueling issue? Also our nearest alternate was an airport 300+ NM away. There was some confusion about the nature of the emergency due to language; and some confusion to where to park. Some hold points were not on the airport diagram. I believe the ATC was giving us the terminal gate name not the number for the ramp. The flight attendants did a great job; the passengers noticed the spray as well and were happy to be back.


Second narrative: I preflighted the airplane and no discrepancies were found. After the fueler started fueling the Captain and I noticed the smell of fuel vapors while performing our cockpit checks. We we're advised by ground personal that there was a fuel leak. I left the cockpit and went down and observed fuel leaking out the NACA fuel vent and pooling under the wing. The Captain had the passengers removed from the airplane and we turned-off the air conditioning packs. Local Maintenance coordinated with Maintenance Control and performed a maintenance procedure verifying that the fueling valves were closed and we were informed the mechanical problem was fixed and signed off in the aircraft maintenance logbook. We had the fire trucks wash the residual fuel off the right wing and proceeded to depart. Upon climbout the Captain received a call from a Flight Attendant in the cabin advising him that a 5 inch diameter fuel spray was streaming-off our right wing which was illuminated by the white Nav light since it was night time and that the left wing showed no vapor trail. After a brief discussion the Captain and I both decided that it was prudent to declare an emergency and return for landing since we didn't want to be flying with the stated problem. I flew the aircraft while the Captain declared an emergency and consulted the QRH which had no procedure for a wing fuel leak; only and engine fuel leak. The Controller granted us an immediate descent to FL40 and a course direct to the IAF on the ILS approach. However; there was confusion by the Controller on the reason for our emergency and it took several follow-up transmissions by the Captain to convey the nature of our emergency. The emergency descent and landing occurred smoothly and without incident. Upon exiting the runway we were asked to taxi to a point on the ramp that wasn't listed on the chart and attempts on my part to clarify the position were met with frustration by the controller. We asked to have the ARFF escort us to the ramp and continued to try and clarify the taxi instructions and we deduced where we were being directed when we saw a guide man on the cargo ramp with lighted wands. My suggestion and concern was the poor communications between us as a flight crew and the Controller. I think it would've been beneficial had we declared 'Mayday; Mayday; Mayday' instead of just stating that 'we're declaring and emergency.' The weather was good and our piloting of the airplane was performed professionally and precisely but I'm concerned that if we had weather to contend with or an aircraft control issue that the poor communication could have distracted us to the point where safety would be impaired. I'm also concerned that a taxi event could occur on the ground/surface due to the lack of charting information listed on taxi spots and parking spots that the Local ATC controllers are directing us to taxi for parking.


Synopsis: B737-800 flight crew is informed of a fuel leak from the right wing vent during passenger boarding. Maintenance is called and a faulty fueling valve is discovered and closed. After departure fuel is reported venting from the right wing tip by a Flight Attendant and the crew elects to return to the departure airport.