scope:

Description of Driving Event:

JSC SR&QA was tasked with performing a quarterly visual weld inspection of the Motion Base Simulator (MBS) located in the Shuttle Mission Simulator facility. The MBS is a dynamically loaded large aluminum structure with over 300 welds, of which approximately 80 welds have exhibited cracking over the past ten years. The 80 welds had been repaired, but many continue to exhibit cracking after a short time due to repetitive dynamic loading resulting from motion and vibration. As a result, these problem welds require continued inspection/evaluation. Previously it took 3 certified welding inspectors (CWI) 6+ hours to locate, access and inspect the 80 welds. Even though the welds were marked with labels, the configuration of the MBS prevented most welds from being readily located. The CWI's spent approximately 4+ hours locating the welds and 2 hours to perform the inspections. Inspection personnel divided the MBS into five separate areas and took high-resolution digital photographs of each area. On each photograph the weld locations were labeled with the appropriate weld number and an arrow pointing to the exact location. A trial run was conducted and all of the welds were located in less than 30 minutes. During subsequent quarterly weld inspections the overall inspection time for three inspectors has been reduced to less than 3 hours. The result is a more than 50% savings for each inspection cycle.