AN ACR MLG LOST CTL OF 1 OF ITS ENGS. IT WOULD NOT COME OUT OF CRUISE PWR.

Narrative

AS THE VNAV RETARDED THROTTLES; THE R ENG ACCELERATED TO 98 PERCENT N1. DISCONNECTED AUTOTHROTTLES. L ENG RESPONDED NORMALLY; BUT R REMAINED AT 98 PERCENT. FOUND IT WAS IMPOSSIBLE TO DSND; MUCH LESS KEEP AIRPLANE BELOW REDLINE; SO ELECTED TO SHUT IT DOWN. PERFORMED NORMAL SINGLE ENG PROCS AS WE CONTINUED TO DSND TO MAKE XING RESTRICTIONS. ALL THE ABOVE HAPPENED JUST AS WE WERE BEING TURNED OVER TO APCH FROM CTR. MADE THE XING AND SPD RESTRICTION OK. AT FIRST WE THOUGHT #1 HAD FAILED. SPD GOT UP TO REDLINE DUE TO HIGH PWR OF #2. BEFORE DECIDING TO SHUT DOWN; DECIDED TO TEST THROTTLE RESPONSE ON BOTH ENGS; BEFORE SHUTTING 1 DOWN. THERE IS NO PROC IN THE BOOK FOR AN ACCELERATED ENG. WITH THAT IN MIND; IT WOULD HAVE BEEN VERY EASY TO SHUT DOWN THE CTLABLE ENG IF BOTH THROTTLES HADN'T BEEN TESTED. ALSO; FOUND YOU CAN'T DSND AN MLG WITH FULL PWR ON 1; CLEAN; WITHOUT GOING TO REDLINE. SUGGEST THAT FAA AND ENG MANUFACTURERS LOOK INTO PROB OF ACCELERATING ENGS. WE UNDERSTAND THIS PROB IS NOT UNCOMMON. ALSO SUGGEST AN APPROPRIATE PROC BE DEVELOPED FOR INCLUSION IN TRAINING SYLLABUS AND EMER PROCS. REMAINDER OF FLT; ILS; AND LNDG WAS NORMAL. DECLARED EMER AS A PRECAUTION; SO TO HAVE THE EQUIP STANDING BY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTING FO STATES THAT MAINT FOUND A BROKEN CABLE TO THE R ENG. THERE WAS NO RESISTANCE AT ALL TO THE THROTTLE MOVEMENT; AND NO RESPONSE FROM THE ENG. THE ENG STAYED AT CRUISE PWR UNTIL SHUT DOWN. SUPPLEMENTAL INFO FROM ACN 234664: THIS WAS 1 SIT WHERE THE DEAD FOOT; BAD ENG LOGIC WAS NOT TRUE AND COULD HAVE LED TO SHUTTING DOWN THE GOOD ENG. OF COURSE; THIS WOULD NOT BE A PROB IN THIS SIT; UNLESS IT WOULD NOT RELIGHT.