Air carrier captain is informed by ATC after takeoff that another flight crew has observed fuel leak...

Narrative:

After takeoff; at approximately 4;000 to 5;000 ft; departure control advised us that a company flight said there was fuel (liquid?) coming from our left wing. To be safe; I declared an emergency and elected to return to land. After landing I stopped the airplane on the runway so arff could inspect the airplane. They said everything looked normal. We then taxied back to the gate (with a fire truck following us). Maintenance found evidence of fuel by the left wing vent and left wing main tank vent plate. They tightened the plate; did some other tests and we left again on the same airplane with no further problems. I suggest that the plate be inspected more often to be sure the screws are tight. Although we saw no abnormal indications in the cockpit; I feel a possible fuel leak from the wing (where the engine is located) could be a dangerous situation.

Original NASA ASRS Text

Title: Air Carrier Captain is informed by ATC after takeoff that another flight crew has observed fuel leaking from the left wing. An emergency is declared and the flight returns to the departure airport where Maintenance does find evidence of a fuel leak and corrects it.

Narrative: After takeoff; at approximately 4;000 to 5;000 FT; Departure Control advised us that a company flight said there was fuel (liquid?) coming from our left wing. To be safe; I declared an emergency and elected to return to land. After landing I stopped the airplane on the runway so ARFF could inspect the airplane. They said everything looked normal. We then taxied back to the gate (with a fire truck following us). Maintenance found evidence of fuel by the left wing vent and left wing main tank vent plate. They tightened the plate; did some other tests and we left again on the same airplane with no further problems. I suggest that the plate be inspected more often to be sure the screws are tight. Although we saw no abnormal indications in the cockpit; I feel a possible fuel leak from the wing (where the engine is located) could be a dangerous situation.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	916348
Time
Date	201010
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Component
Aircraft Component	Fuel System
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe

Air carrier captain is informed by ATC after takeoff that another flight crew has observed fuel leaking from the left wing. An emergency is declared and the flight returns to the departure airport where maintenance does find evidence of a fuel leak and corrects it.