What was found
WHEN THROTTLES ADVANCED NR 2 ENG EXPERIENCED COMPRESSOR STALL, NR 2 ENG BROUGHT BACK TO IDLE. DECLARED EMERG, ACFT LANDED W/O INCIDENT. MX PERF GROUND RUN NR 2 ENG, WHEN THROTTLE RETARDED ENG EXPERIENCED COMPRESSOR STALL. ENG SHUTDOWN, BORESCOPE PERF. BORESCOPE REVEALED DAMAGE TO HIGH STAGE COMPRESSOR SECTION, PIECES OF 6, 7, 8, 9 BLADES MISSING. NUMEROUS BLADES WITH CURLED TIPS. NR 2 ENG REMOVED. TEARDOWN OF ENG REVEALED MINOR HPC BLADE TIP RUB STAGES 1-4 BLADES, HEAVY BLADE TIP RUB STAGE 5, HEAVY AIRFOIL DAMAGE TO BLADES STAGES 6-9. EXCESSIVE RUB 4-9 SPOOL BASE MAT IN AREA OF 6TH STAGE BLADES, DUE TO MACHINING CAUSED BY LIBERATED STATIONARY INTERSTAGE AIRSEALS WITHIN REAR COMPRESSOR CASES.