As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW NOTED A BURNING SMELL AFTER TAKEOFF, FOLLOWED BY VISIBLE SMOKE IN THE AFT PASSENGER CABIN (NO PASSENGERS WERE ONBOARD). ACFT RETURNED TO THE DEPARTURE AIRPORT AND LANDED SAFELY. MAINTENANCE TECHNICIANS CONFIRMED OIL SMELL COMING FROM THE RT ENGINE. BOROSCOPE OF THE RT ENGINE REVEALED OIL RESIDUE AFT OF THE FIRST STAGE COMPRESSOR. THE ENGINE WAS REMOVED FOR REPAIR.