As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD BANG ON TAKEOFF. NR 2 ENGINE SURGE. ENGINE EXPERIENCED A GROUP 3 SURGE, ENGINE SELF RECOVERED AND CONTINUED NORMAL OPERATION. ENGINE EXPERIENCED OPEN CLEARANCES IN THE REAR OF THE COMPRESSOR AND SURGED. ENGINE WAS REMOVED FROM SERVICE AND OVERHAULED.