What was found
FLT NR 668 - MCO - THE NR 1 ENG EXPERIENCED BLEED LOSS AND FIRE WARNING AFTER TAKEOFF. THE EGT ROSE TO 955 DEGREES. THE NR 1 ENGINE THRUST WAS REDUCED AND THE FIRE WARNING CEASED. THE A/C WAS RETURNED TO MSO WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NR 1 ENG 14TH STAGE DUCT RUPTURED WHICH RESULTED IN DAMAGE TO OTHER DUCTS, LINES, AND THE THRUST REVERSER. S/D - THE FAILURE WAS DUE TO HIGH VIBRATORY STRESSES IN THE 14TH STAGE CDP AIR TUBE RESULTING FROM THE 14THE STAGE AIR BLEED TUBE. THE CF6-50 FLEET HAS BEEN MODIFIED BY REMOVING THE 14TH STAGE AIR BLEED TUBE PER GE SB 75-071 (M)