Narrative:

I was assigned to troubleshoot MEL 4-1071 dc-C on aircraft X autothrottle inoperative. On review of the flight crew maintenance report to see what ZZZ1 had done; they had found the l-hand engine binding. I re-tested the autothrottle system and it failed with message; 'left-hand engine pla.' I also observed the l-hand throttle stopped at the 3/4 point of travel. I stopped the test and manually moved the throttles and did feel binding of the l-hand engine throttle at the 3/4 point of travel. Needed to know if the binding was at the fuel flow governor or in the throttle system of the aircraft. At the l-hand engine; I removed the 3 attaching bolts that hold the fuel flow governor control box and cover bracket on. At this point I noted the cover bracket broken and continued to troubleshoot. Once the fuel flow governor control box and cover bracket were removed; I again manually moved the throttles full travel and no binding occurred; the throttles ran smoothly. This proved that the binding was in the fuel flow governor itself. To reconfirm this; I reattached the fuel flow governor control box and cover bracket and the binding returned. I returned to the shop and informed the lead technician of my findings to get the company part number for the broken cover bracket and to print up the northwest paperwork or the 'throttle lever load test' 76-11-00-5. I printed the 'load test' and went back to aircraft X with a 0-6 pound fish scale. Someone else would look up the cover bracket company part number for me. At the aircraft; I performed the 'throttle lever load test' per maintenance manual 76-11-00-5. The maximum force required to move the throttle through full travel including the area of biding was no more than 3.5 pounds; which is below the maximum allowable per maintenance manual 76-11-00-5 of 4.5 pounds. Since the l-hand engine throttle passed the load test; I returned to the shop. There I found that the broken cover bracket was cpn 5533336. I again informed the lead technician of my test findings (he would call technical services with the update but I was not in the room when this happened). I also updated the flight crew maintenance report to show my findings that the fuel flow governor (GOV3005) was the cause of the binding and that the cover bracket was company part #5533336 was broken. Also that I re-tested the l-hand throttle per maintenance manual 76-11-00-5 and it did pass at '3.5 pounds' which is below maximum allowable. Since both GOV3005 and cover bracket 5533336 were not in stock at ZZZ; closed the engine cowl and secured the aircraft. The flight crew maintenance report update I made on apr/sun/05 could have been misread when I said; 'required pressure to move throttle through bind is 3.5 pounds which is below maximum allowable.' in the flight crew maintenance report update I should have said that the force required to move the throttle through full travel and bind area was 3.5 pounds which is within maintenance manual 76-11-05 limits. Also that cover bracket company part 5533336 is just that -- a cover bracket only -- and it does not move with or attach to any part of the moveable pan of the fuel flow governor or throttle. This cover bracket does not impede or limit full throttle travel in any way.

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Original NASA ASRS Text

Title: A B757-200 L ENG THROTTLE WAS FOUND BINDING. TECHNICIAN DESCRIBES WORK ACCOMPLISHED TO LOCATE PROB. PARTS NOT IN STOCK. ITEM CONTINUED DEFERRED.

Narrative: I WAS ASSIGNED TO TROUBLESHOOT MEL 4-1071 DC-C ON ACFT X AUTOTHROTTLE INOP. ON REVIEW OF THE FLT CREW MAINT RPT TO SEE WHAT ZZZ1 HAD DONE; THEY HAD FOUND THE L-HAND ENG BINDING. I RE-TESTED THE AUTOTHROTTLE SYS AND IT FAILED WITH MESSAGE; 'L-HAND ENG PLA.' I ALSO OBSERVED THE L-HAND THROTTLE STOPPED AT THE 3/4 POINT OF TRAVEL. I STOPPED THE TEST AND MANUALLY MOVED THE THROTTLES AND DID FEEL BINDING OF THE L-HAND ENG THROTTLE AT THE 3/4 POINT OF TRAVEL. NEEDED TO KNOW IF THE BINDING WAS AT THE FUEL FLOW GOVERNOR OR IN THE THROTTLE SYS OF THE ACFT. AT THE L-HAND ENG; I REMOVED THE 3 ATTACHING BOLTS THAT HOLD THE FUEL FLOW GOVERNOR CTL BOX AND COVER BRACKET ON. AT THIS POINT I NOTED THE COVER BRACKET BROKEN AND CONTINUED TO TROUBLESHOOT. ONCE THE FUEL FLOW GOVERNOR CTL BOX AND COVER BRACKET WERE REMOVED; I AGAIN MANUALLY MOVED THE THROTTLES FULL TRAVEL AND NO BINDING OCCURRED; THE THROTTLES RAN SMOOTHLY. THIS PROVED THAT THE BINDING WAS IN THE FUEL FLOW GOVERNOR ITSELF. TO RECONFIRM THIS; I REATTACHED THE FUEL FLOW GOVERNOR CTL BOX AND COVER BRACKET AND THE BINDING RETURNED. I RETURNED TO THE SHOP AND INFORMED THE LEAD TECHNICIAN OF MY FINDINGS TO GET THE COMPANY PART NUMBER FOR THE BROKEN COVER BRACKET AND TO PRINT UP THE NW PAPERWORK OR THE 'THROTTLE LEVER LOAD TEST' 76-11-00-5. I PRINTED THE 'LOAD TEST' AND WENT BACK TO ACFT X WITH A 0-6 LB FISH SCALE. SOMEONE ELSE WOULD LOOK UP THE COVER BRACKET COMPANY PART NUMBER FOR ME. AT THE ACFT; I PERFORMED THE 'THROTTLE LEVER LOAD TEST' PER MAINT MANUAL 76-11-00-5. THE MAX FORCE REQUIRED TO MOVE THE THROTTLE THROUGH FULL TRAVEL INCLUDING THE AREA OF BIDING WAS NO MORE THAN 3.5 LBS; WHICH IS BELOW THE MAX ALLOWABLE PER MAINT MANUAL 76-11-00-5 OF 4.5 LBS. SINCE THE L-HAND ENG THROTTLE PASSED THE LOAD TEST; I RETURNED TO THE SHOP. THERE I FOUND THAT THE BROKEN COVER BRACKET WAS CPN 5533336. I AGAIN INFORMED THE LEAD TECHNICIAN OF MY TEST FINDINGS (HE WOULD CALL TECHNICAL SVCS WITH THE UPDATE BUT I WAS NOT IN THE ROOM WHEN THIS HAPPENED). I ALSO UPDATED THE FLT CREW MAINT RPT TO SHOW MY FINDINGS THAT THE FUEL FLOW GOVERNOR (GOV3005) WAS THE CAUSE OF THE BINDING AND THAT THE COVER BRACKET WAS COMPANY PART #5533336 WAS BROKEN. ALSO THAT I RE-TESTED THE L-HAND THROTTLE PER MAINT MANUAL 76-11-00-5 AND IT DID PASS AT '3.5 LBS' WHICH IS BELOW MAX ALLOWABLE. SINCE BOTH GOV3005 AND COVER BRACKET 5533336 WERE NOT IN STOCK AT ZZZ; CLOSED THE ENG COWL AND SECURED THE ACFT. THE FLT CREW MAINT RPT UPDATE I MADE ON APR/SUN/05 COULD HAVE BEEN MISREAD WHEN I SAID; 'REQUIRED PRESSURE TO MOVE THROTTLE THROUGH BIND IS 3.5 LBS WHICH IS BELOW MAX ALLOWABLE.' IN THE FLT CREW MAINT RPT UPDATE I SHOULD HAVE SAID THAT THE FORCE REQUIRED TO MOVE THE THROTTLE THROUGH FULL TRAVEL AND BIND AREA WAS 3.5 LBS WHICH IS WITHIN MAINT MANUAL 76-11-05 LIMITS. ALSO THAT COVER BRACKET COMPANY PART 5533336 IS JUST THAT -- A COVER BRACKET ONLY -- AND IT DOES NOT MOVE WITH OR ATTACH TO ANY PART OF THE MOVEABLE PAN OF THE FUEL FLOW GOVERNOR OR THROTTLE. THIS COVER BRACKET DOES NOT IMPEDE OR LIMIT FULL THROTTLE TRAVEL IN ANY WAY.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.