What was found
NR 1 ENGINE STALLED INFLIGHT. [SUP 4-20-07] SURGE OCCURRED AT TOD; ENGINE REPLACED AT ORD. TEARDOWN REVEALED THAT 1 HP COMPRESSOR STAGE-7 BLADE FAILED IN THE AIRFOIL NEAR THE TIP. THE AMOUNT OF MISSING AIRFOIL WAS APPROXIMATELY 1-SQ.IN. FAILURE BEGAN AS A FATIGUE CRACK AT THE AIRFOIL TRAILING EDGE, AND PROGRESSED FORWARD IN FATIGUE. THIS FRACTURE MODE EVENTUALLY TRANSITIONED TO A DUCTILE OVERLOAD THAT LED TO SEPARATION AT THE MID-CHORD LOCATION. DOWNSTREAM AIRFOIL DAMAGE WAS NOTED ON STAGES 8, 9, AND 10.