A Mechanic and an Inspector report how a chain of events contributed to a Saab-340 right engine change having a new; partially installed left mount removed and the old mount inadvertently re-installed. Factors involved lack of experience and training; lack of new hardware; Crew turnover; lack of adequate Supervision; Lead Mechanic oversight and mis-communications.
Synopsis
A Mechanic and an Inspector report how a chain of events contributed to a Saab-340 right engine change having a new; partially installed left mount removed and the old mount inadvertently re-installed. Factors involved lack of experience and training; lack of new hardware; Crew turnover; lack of adequate Supervision; Lead Mechanic oversight and mis-communications.
Narrative
Mechanic 'X' and I were assigned to install the right-hand engine on a Saab-340 aircraft. Neither one of us had ever removed or installed a Saab engine before so we took our time. After inspecting the old and new parts we began to remove the engine mounts. I removed the left-hand mount and placed it on my tool box. I then filled out the removal information on the yellow parts tag. Mechanic 'X' was ready to install his when he found out that half the hardware was missing. The hardware for this job was ordered short!After I finished filling out the yellow tag I placed the old worn part in the plastic bag and placed the yellow filled out tag in with it and placed it on the table. I then installed the new mount onto the engine with the old hardware but the bolts were only finger tight so they could be replaced with the new hardware later. While waiting for the rest of the hardware I was pulled off the [first] Saab-340 to work on the Brake Valve Assembly of another Saab-340. Before I started on the second Saab-340; I told the other Mechanic that the new part [engine mount] was on the plane with the old hardware but only finger tight.The new brake valve job took me till morning to finish. I did not return to the first Saab-340 at all that night. My Manager informed me of the issue two days later. We didn't have all the hardware needed. If we did I would have installed the mount onto the engine right away. Whoever removed the new part didn't observe that the yellow tag was already filled out next to the old; dirty part. The Inspector didn't verify serial numbers before the engine was installed. Stores found the new part returned to them instead of the old part; reported it and the new left-hand engine mount was then installed.I suggest Ordering all of the hardware. Place an individual on the job who has performed the job before to help and train those of us who have never done the job before. Place two tables next to the aircraft; one for new or saved parts and one for non-serviceable parts.
Second reporter narrative
In the course of replacing the right-hand (RH) engine mounts on a Saab 340-B; one of the old mounts was inadvertently re-installed on the aircraft. The Maintenance was being done in the ZZZ Maintenance hanger. Mechanic 'X' and Mechanic 'Y' and myself as the RII Inspector. I was assigned as the RII that night for the engine change. At the beginning of the shift I began the Inspection of the Aft engine mount Tower which had been previously removed and blended. I verified that the blending was within limits and performed a Dye Penetrant Inspection of the mount for cracks. The new mounts were on a table near the engine. I checked the new mounts and the yellow Tags. The new mounts were installed on the aircraft but not torqued because sufficient hardware was not available. While we were waiting for hardware to arrive I returned the Dye Penetrant equipment to Stores. While I was gone apparently the mounts were removed after the new hardware arrived and that was when the old mount got replaced by mistake. When I returned the mounts were installed on the engine with new hardware. I watched the torquing of the bolts and returned later to look at the Safeties. I was notified by one of the Supervisors that they had received word from first shift Quality Control (QC) that the new part had been returned to Stores. I think part of the problem was that there wasn't good continuity in the project; there were interruptions; the original Mechanic was reassigned to another aircraft. The parts should have been tagged and separated from the new ones. The new and old parts were not easily distinguishable from one another. That is why no one noticed through the rest of the installation that an old part had been installed. When the Mechanic tagged the parts he could have verified that the right [correct] part was being tagged. The correct part was installed on the aircraft after the problem was discovered. When parts are being Tagged it should be verified that the Number on the part coincides with the part removed line on the Removal Tag.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.