What was found
DURING CLIMB OUT, THE CREW HEARD A LOUD BANG, F/A REPORTED A FLASH ON LT SIDE. THEY RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. MX INSPECTED BOTH NR 1 AND NR 2 ENGINE'S, LUBED THE PRBC'S. OPS CHECK GOOD IAW MM 72-00, ERH 70.01, ERH 75.01, AND MM 12-80-0. ACFT WAS RETURNED TO SERVICE.