As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY DECLARED, AND AIR TURNBACK DUE TO LT ENGINE COMPRESSOR STALL & LOUD BANG DURING CLIMB. REDUCED ENGINE SPEED TO IDLE AND COULD NOT ADVANCE THROTTLES WITHOUT ENGINE STALLING AGAIN. PERFORMED BORESCOPE OF HPC AND FOUND A 3RD STAGE BLADE MISSING AND OTHER BLADES WITH EXTENSIVE DAMAGE. REPLACED ENGINE. (9215958) AIRCRAFT WAS GROUNDED.