What was found
DURING CLIMBOUT, FUEL WAS VENTING UNDER THE WING FROM VENT BOX ON LEFT SIDE. AS A PRECAUTIONARY MEASURE, THE FLIGHT CREW ELECTED TO RETURN. LANDED WITHOUT INCIDENT, NO EMERGENCY WAS DECLARED. NO VISIBLE SIGNS OF LEAKAGE DETECTED AND DISTRIBUTION TEST PERFORMED IAW WITH MM 28-20-0, NO DEFECTS NOTED.