Two Mechanics and an Inspector report about a Field trip to replace a bird strike damaged # 3 Slat on the left wing of a B737-300. Slat was installed; but later determined to be not Effective for the aircraft. Lack of adequate data for aircraft Effectivities were noted as contributing factors.
Synopsis
Two Mechanics and an Inspector report about a Field trip to replace a bird strike damaged # 3 Slat on the left wing of a B737-300. Slat was installed; but later determined to be not Effective for the aircraft. Lack of adequate data for aircraft Effectivities were noted as contributing factors.
Narrative
Road trip to ZZZ1 for the purpose of changing the #3 Slat assembly due to a large bird strike. Slat was heavily dented and was not Airworthy. I was along as the Maintenance Inspector to check R.I.I. requirements. When checking for Fits and Fairs of Slat; I observed that the Slat stops on the fixed leading edge were approximately 3/8' inch too high; and would not allow the Slat to Fair with the wing leading edge. Slat effectivity was verified by Maintenance Control by phone. Further checking in ZZZ revealed that the Slat was effective for the B737-300; but only after the accomplishment of the Service Bulletin dealing with the Slat Stop configuration. The modifications required were of a Shop level nature and required an Engineering Authorization to accomplish. I contacted Mr. 'X' in Maintenance Control in ZZZ2; and explained the Stop mis-match. I also consulted with my Supervisor Mr. 'Y'; in ZZZ and he researched the problem. Mr. 'Y' got back to me with a Service Bulletin that needed to be accomplished on the Slat to make it suitable for use on the B737-300. I suggested to Maintenance Control; Mr. 'X'; that we could remove the too large Stops and the Slat would fair correctly. He agreed and authorized me to retract the Slats and check the Fair with the leading edge of the wing. With the Slats retracted; everything was faired. I then contacted Mr.'X' and he said that we would do a Maintenance Ferry Flight to ZZZ1 for the purpose of correcting the Stop mis-match. A Ferry Permit was issued and a Logbook entry was made as per Maintenance Control Mr. 'X' verbiage. It is my understanding that under the previous Parts Stores system; we had multiple Part Numbers (P/N's) for the different configuration Slats; under the current Stores system; we only have one Part Number. We need to have a better means of differentiating the Effectivity of the Slats to the aircraft.
Second reporter narrative
We were on a road trip to ZZZ1 to change #3 slat on a B737-300. We received the Slat and confirmed with Maintenance Control that the Slat effectivity is acceptable with the aircraft we were working on.I was informed by our Flight Safety representative that wrong Slat effectivity was installed. We we're given a wrong effectivity; but Maintenance Control confirmed that it was a good part. We need better support from Maintenance Control.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.