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The foundation of many production aircraft assembly facilities is a more dynamic and unpredictable quantity than we would sometimes care to admit. Any tooling structures constructed on these floors, no matter how thoroughly analyzed or well understood, are at the mercy of settling and shifting concrete, which can cause very lengthy and costly periodic recertification and adjustment procedures. It is with this in mind, then, that we explore the design possibilities for one such structure to be built in Belfast, North Ireland for the assembly of the Shorts C-Series aircraft wings. We evaluate the peak floor pressure, weight, gravity deflection, drilling deflection, and thermal deflection of four promising structures and discover that carefully designed pivot points and tension members can offer significant benefits in some areas.

Figure 1 Global 7000 Business Jet. Photo credit: Robert Backus. The customer’s assembly philosophy demanded a fully integrated flexible pulse line for their Final Assembly Line (FAL) to assemble their new business jets. Major challenges included devising a new material handling system, developing capable positioners and achieving accurate joins while accommodating two different aircraft variants (requiring a “flexible” system). An additional requirement was that the system be easily relocated to allow for future growth and reorganization. Crane based material handling presents certain collision and handover risks, and also present a logistics challenge as cranes can become overworked. Automated guided vehicles can be used to move large parts such as wings, but the resulting sweep path becomes a major operational limitation. The customer did not like the trade-offs for either of these approaches.

Drilling of carbon-fiber-reinforced plastic (CFRP) components in aircraft production presents many challenges. Factors including layup material, layup process, layup orientation, hole tolerance, surface finish, delamination limits, and inspection methods result in a wide range of process times. The purpose of the paper is to provide a framework to understanding the drilling process in CFRP and the resulting hole tolerance, surface finish and delamination. The paper will investigate drilled hole diameters from 3/16\mi (5 mm) up to 1\mi (25.4 mm) drilled thru CFRP/CFRP and CFRP/metallic stacks with automated drilling machines using single-sided clamping.

Growing use of composite materials in aircraft wing construction requires a new generation of drilling machines. Electroimpact developed the LTD machine to address the specific needs posed by large scale composite wing box assembly. The machine maximizes the efficacy of blind access to create a single sided assembly process. Innovative design greatly reduces machine weight and foundation requirements. Optimized processes and automation tools increase the drilling capacity. The mobile machine maximizes plant flexibility by carrying out work on both wing surfaces across multiple assembly jigs. Through thoughtful engineering and thoroughly developed processes the LTD presents a highly capable and cost efficient solution for composite wing box drilling automation.

Manually changing stringer-side tooling on an automatic fastening machine is time consuming and can be susceptible to human error. Stringer-side tools can also be physically difficult to manage because of their weight, negatively impacting the experience and safety of the machine operator. A solution to these problems has recently been developed by Electroimpact for use with its new Fuselage Skin Splice Fastening Machine. The Automatic Tool Changer makes use of a mechanically passive gripper system capable of securely holding and maneuvering twelve tools weighing 40 pounds each inside of a space-saving enclosure. The Automatic Tool Changer is mounted directly to the stringer side fastening head, meaning the machine is capable of changing tools relatively quickly while maintaining its position on the aircraft panel with no machine operator involvement.