Author: Frank Elliott
Company: AGFM / GFM
Phone: (817) 909-2444
Integrated Inspection and Repair Preparation (IIRP) Components Removed from Aircraft Abstract This is a proposed path to reduce sustainment cost by increasing the availability and reliability of critical structures through replacement of artisan dependent inspection and repair operations with computer-based technology for a wide range of components. Those components can include Control Tabs, Outboard and Inboard Aileron Tabs, Rudder Control Tabs, plus Leading and Trailing Edges, Rudders, and Nose, Tail and Blister Domes, Engine Nacelles and Nacelle Thrust Link Fairings, and possibly others.
The current manual practices often include less-than-optimum inspection methods, manual scarfing to remove the defect, and manual patch preparation, all contributing elements of inaccuracy, waste and lengthy, disjointed processes. Due to the nature of these operations, accurate and reliable digital records of repairs on components are not available. With the proposed automated\integrated techniques, a digital record for inspection and repairs will be available.
The GFM organization plus the Northrop Grumman Innovation Systems – Aerospace Structures Division are teaming to identify and demonstrate a suite of integrated technologies to achieve this goal. Similar requirements of certain aircraft components that are removed from an aircraft, including engine nacelles and radomes, have previously been successfully addressed by GFM in organized projects employing the similar strategy as stated above.
Those applications include very accurate CNC scanning techniques to establish an accurate digital model database tied to the reference coordinate system for the structure being evaluated.
Various NDI technologies, in some combination, have been employed to identify suspect areas, plus accurate size and depth of defect. This has included multiple layer composites sandwich structures, which present serious challenges to obtain accurate NDI data beyond the depth of the first sandwich layer. However, after a focused search, our group identified and implemented a technology, which provided very accurate data through both first and second sandwich layers.
This data is then overlaid onto the surface of the component via laser projection techniques for visual identification of the defect areas. The resulting fully integrated cell will employ CNC technology to automatically scarf the defect areas, plus ultrasonically cut the appropriately shaped repair patch materials, and guide the repair technician in the most efficient repair process.
GFM has also conducted demonstrations in which measurements were attained to determine incipient heat damage utilizing FTIR Spectroscopy NDI technology, not possible with other NDI technologies, but very important for heat damage assessment.. This was implemented in the same CNC machine tool that subsequently performed the scarfing.
The Northrop Grumman organization brings to the table the background of having developed and produced NDI systems.