What was found
ATB- THE CREW PERFORMED AN AIR TURN BACK DUE TO LEFT ENGINE COMPRESSOR STALL WITH RISE IN EGT. CORRECTIVE ACTION: INSPECTED INLET, EXHAUST, CHIP DETECTORS, 2.5 BLEED AND VSV SYSTEM. NO DISCREPANCIES FOUND. BOROSCOPED HPC SECTION FOR COMPRESSION SURGE WITH NO LIMITING DAMAGE NOTED. BIRD STRIKE INSPECTION PER AMM 72-00. NO DEFECTS NOTED. R/R'D EEC PER AMM 73-21-04. COMPLIED WITH OVERTEMP INSP PER AMM 72-00. OPENED UP HPT STAGE ONE FOR BOROSCOPE COMPLIANCE 525 PER MAINT. REQUEST PER AMM 72-00-00. FOUND NO DAMAGE. RAN ENGINE TO 1.40 LOUD COMPRESSOR STALL WITH FIREBALL. REPLACED NR 1 ENGINE ON LOGPAGE 1444103.