A MECHANIC REFERENCES THE LANGUAGE IN THE MAINT MANUAL THAT INSTRUCTS MECHANIC TO 'LOOSELY INSTALL CLAMPS' WHILE REPLACING THE #2 CF6 ENG THROTTLE PUSH-PULL CABLE THAT MAY HAVE CONTRIBUTED TO AN INFLIGHT SHUTDOWN.
Synopsis
A MECHANIC REFERENCES THE LANGUAGE IN THE MAINT MANUAL THAT INSTRUCTS MECHANIC TO 'LOOSELY INSTALL CLAMPS' WHILE REPLACING THE #2 CF6 ENG THROTTLE PUSH-PULL CABLE THAT MAY HAVE CONTRIBUTED TO AN INFLIGHT SHUTDOWN.
Narrative
WHILE REPLACING #2 ENG THROTTLE PUSH/PULL CABLE; REFING THE WORK CARD; FOUND WORK CARD TO BE VERY VAGUE ON THE ROUTING OF CABLE. REFED THE MAINT MANUAL FOR INSTALLATION OF CABLE AND FOUND THE SAME TO BE TRUE THERE ALSO. THERE ARE NO ILLUSTRATIONS OR WORDING AS TO THE PROPER ROUTING OTHER THAN 'LOOSELY INSTALL CLAMPS.' I CONTINUED WITH INSTALLATION OF CABLE TO THE BEST OF MY KNOWLEDGE WITH THE REF MATERIAL AT HAND. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE PUSH-PULL CABLE ALSO ROUTES TO THE THRUST REVERSER INTERLOCK; THEN IN-OUT OF A 'FEED' THROUGH TO THE MEC FOR THE #2 ENGINE. THE CABLE REPLACEMENT WAS OVER TWO YEARS AGO. REPORTER STATED HE WAS TOLD A HYD LINE HAD BEEN REPLACED; AFTER HIS CABLE CHANGE; AND DURING THE SUPPORTING METAL BRACKET REINSTALLATION FOR THE HYD HOSE; SOMEHOW HAD POSITIONED THE THROTTLE CABLE INSIDE THE METAL BRACKET. AS A RESULT; THE METAL BRACKET STARTED CUTTING INTO THE METAL BRAIDED THROTTLE CABLE; OVER TIME; EXPOSING THE INNER CABLE TO WATER INGRESS; WHICH FROZE DURING FLIGHT. THE FLIGHT CREW HAD WRITTEN-UP THE THROTTLE FOR BINDING AND STICKING THE PREVIOUS DAY. THE COWLINGS WERE NOT OPENED FOR TROUBLE SHOOTING. MAINT CHECKED THE AUTO THROTTLE AND HANDLES FOR MOVEMENT ONLY. REPORTER STATED THE FOLLOWING DAY; ON APPROACH; THE #2 ENG THROTTLE DID BIND AND ENG SUDDENLY WENT TO IDLE; AND APPARENTLY SHUT DOWN. THE ENG PUSH-PULL CABLE HAD BIRD CAGED; MOSTLY FROM THE FROZEN WATER INGRESS CAUSED BY THE CHAFING CUT INTO THE CABLE
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.