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In Aeronautic industry, when we launch a new industrialization for an aircraft sub assembly we always have the same questions in mind for drilling operations, especially when focusing on lean manufacturing. How can we avoid dismantling and deburring parts after drilling operation? Can a drilling centre perform all the tasks needed to deliver a hole ready to install final fastener? How can we decrease down-time of the drilling centre? Can a drilling centre be integrated in a pulse assembly line? How can we improve environmental efficiency of a drilling centre? It is based on these main drivers that AIRBUS has developed, with SPIE and SOS, a new generation of drilling centre dedicated for hard materials such as titanium, and high thicknesses. The first application was for the assembly of the primary structure of A350 engine pylons. The main solution that was implemented meeting several objectives was the development of orbital drilling technology in hard metal stacks.

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 re-certification 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.

Serial link articulated robots applied in aerospace assembly have largely been limited in scope by deficiencies in positional accuracy. The majority of aerospace applications require tolerances of +/−0.25mm or less which have historically been far beyond reach of the conventional off-the-shelf robot. The recent development of the accurate robot technology represents a paradigm shift for the use of articulated robotics in airframe assembly. With the addition of secondary feedback, high-order kinematic model, and a fully integrated conventional CNC control, robotic technology can now compete on a performance level with customized high precision motion platforms. As a result, the articulated arm can be applied to a much broader range of assembly applications that were once limited to custom machines, including one-up assembly, two-sided drilling and fastening, material removal, and automated fiber placement.

Developing the most advanced wing panel assembly line for very high production rates required an innovative and integrated solution, relying on the latest technologies in the industry. Looking back at over five decades of commercial aircraft assembly, a clear and singular vision of a fully integrated solution was defined for the new panel production line. The execution was to be focused on co-developing the automation, tooling, material handling and facilities while limiting the number of parties involved. Using the latest technologies in all these areas also required a development plan, which included pre-qualification at all stages of the system development. Planning this large scale project included goals not only for the final solution but for the development and implementation stages as well. The results: Design/build philosophy reduced project time and the number of teams involved. This allowed for easier communication and extended development time well into the project.

Over 1,200 large diameter holes must be drilled into the side-of-body join on a Boeing commercial aircraft's fuselage. The material stack-ups are multiple layers of primarily titanium and CFRP. Due to assembly constraints, the holes must be drilled for one-up-assembly (no disassembly for deburr). In order to improve productivity, reduce manual drilling processes and improve first-time hole quality, Boeing set out to automate the drilling process in their Side-of-Body join cell. Implementing an automated solution into existing assembly lines was complicated by the location of the target area, which is over 15 feet (4 meters) above the factory floor. The Side-of-Body Drilling machines (Figure 1) are capable of locating, drilling, measuring and fastening holes with less than 14 seconds devoted to non-drilling operations. Drilling capabilities provided for holes up to ¾″ in diameter through stacks over 4.5″ thick in a titanium/CFRP environment.

Currently the wing box rib assembly process requires the manual location and temporary fixing of components within product specific jig or fixtures for drilling. After drilling and reaming, parts are separated, cleaned, deburred prior to adding sealant, reclaiming and final bolting, but this may significantly increase cost, manufacturing lead-time, reduces flexibility and cannot usually be economically modified for use on other aircraft types. Due to potential increase in demand for the next generation single isle aircraft, existing tooling solutions have to be improved and new technologies have to be developed. This paper describes the development and testing of flexible tooling to provide clamping and support for drilling wing box ribs to mating rib posts within a restricted environment. Results are presented along with a discussion of the problems that may be encountered during clamping trials.

One of the largest advancements in the use of the Flextrack technology is the addition of automated fastener installation on the Multifunction Flextrack made by Electroimpact. The new Flextrack installs SSTF (Single Sided Temporary Fasteners) into the holes it drills without removing clamp-up force from the workpiece. This is the first Flextrack to drill and install fasteners and its functionality goes beyond even these functions. The fasteners, SSTF bolts, are increasingly replacing more cumbersome and manual tools for temporary fastening of aerospace components during assembly. They provide doweling, clamp-up, and feature a compact head to facilitate machine installation. The new Multifunction Flextrack carries the bolts on the machine head as opposed to being fed through a feed tube. A Bolt Cartridge System carries up to 80 bolts onboard the Flextrack and the Cartridges can be quick changed for use with several different diameters.

Wing and fuselage aircraft structures require large precise tools for assembly. These large jigs require periodic re-certification to validate jig accuracy, yet metrology tasks involved may take the tool out of service for a week or more and typically require highly specialized personnel. Increasing the time between re-certifications adds the risk of making out-of-tolerance assemblies. How can we reduce jig re-certification down time without increasing the risk of using out-of-tolerance tooling? An alternative, successfully tested in a prototype tool, is to bring automated metrology tools to bear. Specifically, laser tracker measurements can be automated through a combination of off-the-shelf & custom software, careful line-of-sight planning, and permanent embedded targets. Retro-reflectors are placed at critical points throughout the jig. Inaccessible (out of reach) tool areas are addressed through the use of low cost, permanent, shielded repeatability targets.

Design and production of an assembly system for a major aircraft component is a complex undertaking, which demands a large-scale system view. Electroimpact has completed a turnkey assembly line for producing the wing, flap, and aileron structures for the COMAC C919 aircraft in Xi’an, China. The project scope includes assembly process design, material handling design, equipment design, manufacture, installation, and first article production support. Inputs to the assembly line are individual component parts and small subassemblies. The assembly line output is a structurally completed set of wing box, flaps, and ailerons, for delivery to the Final Assembly Line in Shanghai. There is a trend toward defining an assembly line procurement contract by production capacity, versus a list of components, which implies that an equipment supplier must become an owner of production processes.

The paper describes the methodology of contact problem solving that is used in specialized software code aimed at simulation of aircraft assembly process. For considered class of problems it is possible to radically reduce the number of unknowns without loss of accuracy. The results of validation of developed code against physical experiments and commercial FEM codes are also given.

Single Sided Slave Fasteners (SSSF) or Single Sided Temporary Fasteners (SSTF) are increasingly replacing more cumbersome and manual tools for temporary doweling and clamping of aerospace components during assembly. Their ability to clamp provide doweling and clamping reduce the amount of tooling required. Due to their low profile and blind (one-sided) capability, the key benefit of this new technology is the ability to install these fasteners with automated machines. Electroimpact has developed machines to feed primarily SSTF bolts made application-specific by Centrix LLC [ 1 ]. The application discussed in this paper presented problems of confined spaces where a variety of fasteners were required to be fed automatically. To address this, Electroimpact developed new Bolt Injector and Bolt Inserter technology to feed multiple diameters of SSTF bolts in a very small package. Application-specific SSTF were designed such that multiple diameters could be fed through one feed tube.

Electroimpact revisited a piece of automation history this year. In 1989, Electroimpact delivered its first ever Automated Electromagnetic Riveting and Assembly Cell or A.E.R.A.C. to Textron Aero Structures, now Vought Aircraft Industries. These machines produce upper wing panels for Airbus A330/340 aircraft. They were the precursor to the Low Voltage Electromagnetic Riveters or LVER's producing wing panels for Airbus single isle, A340 and A380 programs in Broughton, Wales, UK. In 2009, Electroimpact delivered two next generation AERAC machines to Vought Aircraft Industries. A significant design challenge was to hold the moving mass for the entire machine under 5220 kg without sacrificing performance of the LVER. These machines employ several new technologies to achieve this including Electroimpact's latest generation rivet injector, an integrated headstone load cell, and GE Fanuc's customer board.

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.

The paper is devoted to the simulation of A320 wing assembly on the base of numerical experiments carried out with the help of ASRP software. The main goal is to find fasteners’ configuration with minimal number of fastening elements that provides closing of admissible initial gaps. However, for considered junction type initial gap field is not known a priori though it should be provided as input data for computations. In order to resolve this problem the methodology of random initial gap generation based on available results of gap measurements is developed along with algorithms for optimization of fasteners' configuration on generated initial gaps. Presented paper illustrates how this methodology allows optimizing assembly process for A320 wing.

Automated collar and nut installation requires complex hardware on the wet side of the spar or wing panel. Wet side automatic tool changers are becoming common but an operator is often required to connect electrical, pneumatic and fastener feed system components. This is unacceptable in a lights-out cell, and any fully automatic solution must be reliable while satisfying demanding design requirements. Figure 1 Wet side anvil for nut installation. The 737 Spar Assembly Line (SAL) is a new lights-out machine cell at the Boeing factory in Renton, Washington. The SAL machines are equipped with a unique fully automatic tool changer (ATC). The wet side ATC interface is designed to automatically connect conventional as well as more unique services such as fastener feed. The fastener feed ATC module, called the “spinner,” rotates with the machine’s wet side rotary axis (C axis). It consists of a stack of rotors that rotate inside of a stationary annulus.

Pulsed assembly lines are providing an enormous potential to the aviation industry, especially in terms of reduced lead times, optimized asset utilization and an increased ratio of value adding processes. As it comes near to flow manufacturing the realization of a pulsed assembly line leads to special requirements to the use of NC programs for automated drilling and fastening processes, especially as a result of the unique part positions upon each pulse and concerning the balancing of the work onto several serialized fastening machines. The key to those challenges are versatile NC part programs that eliminate the need for any additionally written NC programs by self-adapting onto the concrete situation within the working areas of the production line.

In Aeronautic industry, when we launch a new industrialization for an aircraft sub assembly we always have the same questions in mind for drilling operations, especially when focusing on lean manufacturing. How can we avoid dismantling and deburring parts after drilling operation? Can a drilling centre perform all the tasks needed to deliver a hole ready to install final fastener? How can we simplify specific jigs used to maintain parts during drilling operations? How can we decrease down-time of the drilling centre? Can a drilling centre be integrated in a pulse assembly line? How can we improve environmental efficiency of a drilling centre? It is based on these main drivers that AIRBUS has developed, with SPIE and SOS, a new generation of drilling centre dedicated for hard materials such as titanium, and high thicknesses. The first application was for the assembly of the primary structure of A350 engine pylons.

Automation in aerospace industry is often in the form of dedicated solutions and focused on processes like drilling, riveting etc. The common industrial robot has due to limitations in positional accuracy and stiffness often been unsuitable for aerospace manufacturing. One major cost driver in aircraft manufacturing is manual assembly and the bespoke tooling needed. Assembly tasks frequently involve setting relations between parts rather than a global need for accuracy. This makes assembly a suitable process for the use of force control. With force control a robot equipped with needed software and hardware, searches for desired force rather than for a position. To test the usefulness of force control for aircraft assembly an experimental case aligning a compliant rib to multiple surfaces was designed and executed. The system used consisted of a standard ABB robot and an open controller and the assembly sequence was made up of several steps in order to achieve final position.

The aerospace manufacturing sector is continuously seeking automation due to increased demand for the next generation single-isle aircraft. In order to reduce weight and fuel consumption aircraft manufacturers have increasingly started to use more composites as part of the structure. The manufacture and assembly of composites poses different constraints and challenges compared to the more traditional aircraft build consisting of metal components. In order to overcome these problems and to achieve the desired production rate existing manufacturing technologies have to be improved. New technologies and build concepts have to be developed in order to achieve the rate and ramp up of production and cost saving. This paper investigates how to achieve the rib hole key characteristic (KC) in a composite wing box assembly process. When the rib hole KC is out of tolerances, possibly, the KC can be achieved by imposing it by means of adjustable tooling and fixturing elements.

During mechanical assembly, individual parts are joined by different types of fasteners which are commonly to be installed into tightly tolerated holes. Drilling of widely used modern materials like CFRP and titanium leads to challenges in terms of tool and process development. A significant challenge is one step drilling in assemblies made from mixed material stacks. It results in deviating hole diameters making the additional reaming operation essential.”But also drilling of thick single material stacks imposes difficulties in terms of hole tolerance, chip extraction, heat accumulation and lubrication issues, leading to the necessity of drilling in several steps to achieve the required hole quality and integrity. During orbital drilling the drive spindle rotates eccentrically in addition to tool rotation and feed movement, leading to a circular path of the cutting tool. Orbital drilling can offer advantages compared with conventional drilling and reaming.