What was found
BOS - FLT 2851 - AT ROTATION, CREW HEARD AND FELT A LOUD BANG. ALL ENGINE INDICATIONS WERE NORMAL. FLAMES OR A FLASH WERE LATER REPORTED BY A PASSENGER OFF THE RIGHT SIDE OF THE AIRCRAFT. AT APPROXIMATELY 5,000 FT. CAPTAIN DECLARED AN EMERGENCY AND PREPPED THE CABIN. FLIGHT RETURNED TO FIELD TO FIELD AT BOS AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE ACCOMPLISHED A BOROSCOPE INSPECTION OF THE RIGHT ENGINE COMPRESSOR AND HOT SECTION PER MAINTENANCE MANUAL CHAPTER 72. NO DEFECTS NOTED. ACCOMPLISHED POWER RUN PER MM 71-09-200. ALL PARAMETERS CHECK GOOD. (M)