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With composite skins and structures, the exact thickness of a part stack is indeterminate, and thus the fastener grip length for any particular hole cannot be known with certainty, from engineering data alone. A common practice on the assembly line is to provide “overs and unders” - that is, one or two grips lengths above and below the expected fastener length. Unless all of the fasteners are kept line-side which slows production operations, pre-kitted fasteners will require a tremendous amount of return-to-stock. Test fitting every fastener before sealant application and/or delivering 200-400% more fasteners than are needed for the task are not a good value for production. This paper will discuss the development processes and production applications of making fast, accurate stack thickness measurements that are correlated to each particular hole, creating the as-built kit list, and then delivering the kitted fasteners to the production line in the order that they will be installed.

Projection systems are an optically projected 3-D sequence of operations that will guide an assembly technician through a set of complex operations with an intuitive instruction set that is portable and can be quickly set up in complex work areas. Example assembly applications include an aircraft baggage hold of a commercial jet, an inlet duct of a fighter jet, or inside a fuselage of a business jet. Clear, easy-to-follow instructions have been demonstrated to significantly improve assembly time and reduce rework. In many cases, instructions can be completely language independent allowing people of different nationalities to look at the same projection and work the same way without requiring additional instructions. This system provides increased uniformity of span time for given tasks between workers with a wide range of experience which improves scheduling.

Although robots and other automation-related technologies have made tremendous improvements in recent years, there are still many cases where a fully automated system is impractical. Reasons for this impracticability are widely varied but include: a production rate that will not support an adequate business case for a costly, fully automated system, the risk of an error is too great to bear, or part variability from ship-to-ship requires significant real-time decision making that can be challenging for a robot. Three-dimensional, optically projected work instructions can offer a practical solution that provides a significant benefit to the aircraft manufacturer at a price that is approximately 10% of the cost of a fully automated system. In many applications, the semi-automated solution will result in a production rate that is equal to the fully automated system.

Tooling structures to make wing/wing, fuselage/fuselage, and wing/fuselage mates have long been rather massive tools. Not only are these tools large and expensive, but they often obstruct the very drilling and fastening work to be done in the mate tool. Furthermore, these legacy mate tools can only do one job - a mate tool cannot be used for a different airplane, or even a different part of the same airplane. A flexible, more versatile system will lower the cost of aircraft with a low quantity production run planned, and a more open design can reduce the cost of assembly on a high production aircraft. This paper will discuss the development and recent breakthroughs that allow the mating of any size aircraft sections with very high precision using only a set of specialized jacks that provide six degrees-of-freedom coupled with a non-contact measurement system.