EMB ERJ 145 ER/LR
Maintenance Powerplant; Maintenance Airframe
Confusion; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
General Maintenance Action
Aircraft; Human Factors
During accomplishment of Engineering Order (E/O) EM-53AD-2231; Part-D; Section-B-1) it was discovered that the bolts (4 each) that I installed were mistaken for the new bolts that should have been installed.  During a previous step in the accomplishment instructions; Part D; Section A-2); it is outlined to remove bolt Part Number (P/N) NAS6405A18. At some point; new bolts with the same part number were requested and signed out from the Parts Department and stored near a certification containing Part Number MS14181-05020L. On the Engineering Order (E/O); the step to install the lower Eyelet Fitting is on the next page at the top of the E/O and says to install the Fitting using bolts Part Number MS1418105018L or MS1418105020L.A review of all previous steps was done to verify that all previous steps were complied with and signed-off before moving on to the installation of the bolts. When I installed the bolts; I retrieved the bolts from where they were stored; verified the Part Number (P/N) that was on the certification matched the E/O paperwork; however I was unaware that the bolts that were issued did not match the certification.  [Recommend that] if the steps on the Engineering Order to remove a bolt and install a new bolt were integrated into one step; this would greatly reduce the chances of inadvertently installing the wrong bolt. An example would be: Remove bolt Part Number NAS6405A18 and discard and install bolt Part Number MS14181-05020L. Another suggestion would be to ensure when hardware is issued; it should be issued in the bag containing the correct certification at all times until the moment of use; to eliminate mismatching hardware with [different] certifications. Inquiry by FAA into accomplishment of an Engineering Order. Possible incorrect hardware used. Flight delay. Manager Line Maintenance.
A Maintenance Manager was informed he had installed four incorrect replacement bolts at the lower Eyelet Fitting for the cockpit windshield center-post to the forward fuselage on an EMB-145 aircraft. He had verified the Part Number (P/N) on a certification sheet had matched the Engineering Order (E/O); but was unaware that the bolts that were issued did not match the certification.