Narrative:

Over the past yr we have been accomplishing engineering order X. One of the items is to move a clamp to a lower hole. We then fill the empty hole. The paperwork calls to fill the hole with a rivet. This is a 4 hour job just to install the rivet. We contacted engineering to get some kind of relief to install a screw instead. We were originally told that would be ok because it would be covered under standard fastener substitution. So we continued installing the screw. It has been brought to our attention that boeing will not allow this to be substituted. Boeing should allow the screw to be installed. The company is changing the engineering order and we have been told all the affected aircraft will be looked at and addressed by the due date of the airworthiness directive. Callback conversation with reporter revealed the following information: reporter stated the specific rivet (fastener) required as a hole plug are 7/32 diameter 'D' type fasteners; that must be driven (bucked); using a bucking bar on the tail side. The required fasteners are part of an airworthiness directive (ad) requiring the repositioning of the clamps securing the engine generator feeder cables to a lower section on the same bracket; after drilling two new holes. The original factory upper holes need to be filled to prevent any future use of that location on the bracket for attaching the generator feeder cable clamps to. These generator cables run between the engine pylon and the wing root on the forward side of the wing forward spar. The original factory location of the clamps on the upper section of this bracket; positioned the generator cables dangerously close to the leading edge slat track. The clamps tend to rotate somewhat; allowing for cable chafing and further reducing the limited gap. Evidently; reports of slat track contacting and damaging the feeder cables during slat track movement gave rise to the (ad) being issued. The bracket factory holes requiring the plug rivets are in a difficult location in the wing leading edge where the slat; the slat torque tubes; the main pneumatic supply duct and other electrical wire bundles are also located. For the past year; mechanics have been installing a screw; in lieu of the more difficult rivet under the direction of their engineering department that assumed boeing would approve the fastener substitution. Boeing; however; did not grant approval. Reporter further stated that all the aircraft with the screw fasteners will have to be reworked to comply with the (ad) note. Due to the bracket's location and difficulty of installing the required rivets; engineering has decided to have maintenance remove the entire bracket; install the required rivets; drill the new holes for repositioning the clamps and re-install the bracket.

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Original NASA ASRS Text

Title: A B757-200 A.D. REQUIRING A SPECIFIC TYPE OF RIVET (FASTENER) TO BE USED AS A HOLE PLUG ON A BRACKET SECURING THE ENG GENERATOR FEEDER CABLES WAS NOT COMPLIED WITH.

Narrative: OVER THE PAST YR WE HAVE BEEN ACCOMPLISHING ENGINEERING ORDER X. ONE OF THE ITEMS IS TO MOVE A CLAMP TO A LOWER HOLE. WE THEN FILL THE EMPTY HOLE. THE PAPERWORK CALLS TO FILL THE HOLE WITH A RIVET. THIS IS A 4 HR JOB JUST TO INSTALL THE RIVET. WE CONTACTED ENGINEERING TO GET SOME KIND OF RELIEF TO INSTALL A SCREW INSTEAD. WE WERE ORIGINALLY TOLD THAT WOULD BE OK BECAUSE IT WOULD BE COVERED UNDER STANDARD FASTENER SUBSTITUTION. SO WE CONTINUED INSTALLING THE SCREW. IT HAS BEEN BROUGHT TO OUR ATTN THAT BOEING WILL NOT ALLOW THIS TO BE SUBSTITUTED. BOEING SHOULD ALLOW THE SCREW TO BE INSTALLED. THE COMPANY IS CHANGING THE ENGINEERING ORDER AND WE HAVE BEEN TOLD ALL THE AFFECTED ACFT WILL BE LOOKED AT AND ADDRESSED BY THE DUE DATE OF THE AIRWORTHINESS DIRECTIVE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE SPECIFIC RIVET (FASTENER) REQUIRED AS A HOLE PLUG ARE 7/32 DIAMETER 'D' TYPE FASTENERS; THAT MUST BE DRIVEN (BUCKED); USING A BUCKING BAR ON THE TAIL SIDE. THE REQUIRED FASTENERS ARE PART OF AN AIRWORTHINESS DIRECTIVE (AD) REQUIRING THE REPOSITIONING OF THE CLAMPS SECURING THE ENGINE GENERATOR FEEDER CABLES TO A LOWER SECTION ON THE SAME BRACKET; AFTER DRILLING TWO NEW HOLES. THE ORIGINAL FACTORY UPPER HOLES NEED TO BE FILLED TO PREVENT ANY FUTURE USE OF THAT LOCATION ON THE BRACKET FOR ATTACHING THE GENERATOR FEEDER CABLE CLAMPS TO. THESE GENERATOR CABLES RUN BETWEEN THE ENG PYLON AND THE WING ROOT ON THE FORWARD SIDE OF THE WING FORWARD SPAR. THE ORIGINAL FACTORY LOCATION OF THE CLAMPS ON THE UPPER SECTION OF THIS BRACKET; POSITIONED THE GENERATOR CABLES DANGEROUSLY CLOSE TO THE LEADING EDGE SLAT TRACK. THE CLAMPS TEND TO ROTATE SOMEWHAT; ALLOWING FOR CABLE CHAFING AND FURTHER REDUCING THE LIMITED GAP. EVIDENTLY; REPORTS OF SLAT TRACK CONTACTING AND DAMAGING THE FEEDER CABLES DURING SLAT TRACK MOVEMENT GAVE RISE TO THE (AD) BEING ISSUED. THE BRACKET FACTORY HOLES REQUIRING THE PLUG RIVETS ARE IN A DIFFICULT LOCATION IN THE WING LEADING EDGE WHERE THE SLAT; THE SLAT TORQUE TUBES; THE MAIN PNEUMATIC SUPPLY DUCT AND OTHER ELECTRICAL WIRE BUNDLES ARE ALSO LOCATED. FOR THE PAST YEAR; MECHANICS HAVE BEEN INSTALLING A SCREW; IN LIEU OF THE MORE DIFFICULT RIVET UNDER THE DIRECTION OF THEIR ENGINEERING DEPT THAT ASSUMED BOEING WOULD APPROVE THE FASTENER SUBSTITUTION. BOEING; HOWEVER; DID NOT GRANT APPROVAL. REPORTER FURTHER STATED THAT ALL THE ACFT WITH THE SCREW FASTENERS WILL HAVE TO BE REWORKED TO COMPLY WITH THE (AD) NOTE. DUE TO THE BRACKET'S LOCATION AND DIFFICULTY OF INSTALLING THE REQUIRED RIVETS; ENGINEERING HAS DECIDED TO HAVE MAINT REMOVE THE ENTIRE BRACKET; INSTALL THE REQUIRED RIVETS; DRILL THE NEW HOLES FOR REPOSITIONING THE CLAMPS AND RE-INSTALL THE BRACKET.

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.