Date: 201304
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Fuel System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Attendant; Person Observer; Person Passenger
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Maintenance Action; General Declared Emergency
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We departed and headed out runway heading. Once airborne and given [to] Departure we continued climb and were assigned a right turn with a further climb to 10;000 FT. At that point Departure informed us that Tower was relaying a message that our aircraft was observed leaking a visible stream of what appeared to be fuel during the takeoff and climbout. We asked ATC to standby. I called the Flight Attendant and asked her to walk back and verify if there was anything streaming from the wings. She informed me that a passenger was saying they had been watching a fluid leaking from the right wing. We leveled off maintained 200 KTS to slow the pace of events and see what was going on. We had same fuel flow on engines; pumps operating normally but fuel was now lower in the right tank at a rate faster than the left tank quantity reading. We informed ATC that we would like to start heading back to the airport. We received vectors back and I asked the First Officer to notify company and set landing data. I called the Flight Attendant and informed her that we felt there may be a fuel leak and that we would return as a precaution. I let her know the nature of our situation; time to landing; no evacuation or abnormal situation; and asked that she make a PA (to reduce workload on us). The First Officer ACARS'd the Dispatcher; Set the landing data and we ran and in-range; and approach check. The QRH applicable sections were completed by notifying the company and landing; we did not opt to crossfeed as we were immediately able to begin the approach due to our close proximity and being within fuel balance. ATC asked if we were declaring an emergency and I made the decision to do so given the unknown location and flow of fuel; with the intention to have us checked after landing so as not to cause a hazard on the ramp. We briefed a visual approach; an overweight landing; and I noticed that landing data returned a planned landing weight that didn't make sense. We had changed our destination in the flight plan but landing data showed us landing underweight and we were still over due to not burning the fuel it had calculated as burned; we manually adjusted the speed for the heavier aircraft. The touchdown was gentle and minimal breaking needed as we rolled out. As we exited the runway I asked that the ARFF check around the plane to make sure we were not going to leak a lot of fuel onto the ramp. The break was set; PA made by me to the passengers; and a call made to the Flight Attendant. ARFF informed that there was some fuel leaking along the wing and the center of the fuselage but limited and safe to continue to ramp. They escorted us back to gate; following behind. Normal checklists were completed. Once back at the gate we deplaned. A walk around revealed a wet under-wing area on the outboard portion of the right wing with fuel also running down to the root. We also called company Maintenance and they had Contract Maintenance came out. The Mechanic removed some panels and we observed the area inside the wing; outboard of the fuel tanks; was soaked with fuel. Once company Maintenance arrived they opened fuel tank and showed me that the flapper valve was missing/broken away. Also; while conducting a post flight I noticed a small hydraulic leak from the #4 brake line and the right main gear. This was also reported to Maintenance and the mechanics were able to bring out the parts to fix that issue as well.The threats here are the feeling that everything has to be done ASAP and all at once; but time to deal with an issue like this does exist. While I felt it was the best course of action to divert back to the airport; because I didn't know exactly what was wrong; I did feel that we could take vectors; complete our checklists; and brief the approach. The threats were also aircraft equipment; airport traffic; reliance on outside reports and passenger reports of a possible leak. Also the controller needs are different than our needs in terms of information. I was happy to see my First Officer ask ATC to standby when they were seeking information while we were completing a checklist or he was entering FMC data. The Flight Attendant kept the passengers calm by following her procedures in a collected manner. I feel we handled the situation in a safe manner. This situation makes one wonder if under similar circumstances a flight would/should continue because with a lot of fuel uploaded it is not unusual to vent some fuel; and sometimes passengers see a vortex trail and think its fuel. In this case I had several pieces of information that made me question the likelihood of venting being the culprit; so I erred on the side of caution.




Synopsis: EMB145 Captain is informed from multipule sources that fuel is venting from the right wing tip. The Captain elects to return to the departure airport for an overweight landing after declaring an emergency. Maintenance discovered that a vent valve in the right wing tip had failed.