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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 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.

Once limited by insufficient accuracy, the off-the-shelf industrial robot has been enhanced via the integration of secondary encoders at the output of each of its axes. This in turn with a solid mechanical platform and enhanced kinematic model enable on-part accuracies of less than +/−0.25mm. Continued development of this enabling technology has been demonstrated on representative surfaces of an aircraft fuselage. Positional accuracy and process capability was validated in multiple orientations both in upper surface (spindle down) and lower surface (spindle up) configurations. A second opposing accurate robotic drilling system and full-scale fuselage mockup were integrated to simulate doubled throughput and to demonstrate the feasibility of maintaining high on-part accuracy with a dual spindle cell.

In an attempt to be more flexible and cost effective, Aerospace Manufacturers have increasingly chosen to adapt a manufacturing style which borrows heavily from the Automotive industry. To facilitate this change in methodologies a system for locating robots has been developed which utilizes cameras for both locating and guidance of a mobile platform for a robot with drilling and fastening end effector.

Traditionally, automated fiber placement (AFP) motion platforms use rack and pinion drive trains coupled through a gearbox to a rotary motor. Extensive use of non-contact linear motors on a new AFP motion platform produces a quiet, low-maintenance system without sacrificing precision. A high-rail gantry arrangement allows dynamic performance improvements to machine acceleration and speed, while lowering power consumption costs and capital expenses. The seventh axis incorporated into the machine arrangement effectively produces an effective “five sides of a cube” work envelope, permitting complex spar and panel fabrication.

Since Automated Fiber Placement (AFP) is used to manufacture twin-aisled commercial aircraft parts, extremely large envelope machines are often required and appropriate. Additionally, for very large parts, the average AFP course length may be on the order of one to two meters, and the part may have numerous contours. With courses of this length, a high acceleration machine is necessary to achieve fast laydown rates because the machine is frequently starting and stopping. Part contour also requires high acceleration machine axes to accurately maintain the AFP tow path at high feedrates. Large machines with high accelerations result in very large loads on bearings. Large loads and the long, high speed axis travels associated with large envelope machines make achieving a long service life difficult. Designing efficient, lightweight machine structures becomes critical to provide long machine service life.

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.

Manufacturing C cross-sectional components with high aspect ratios out of carbon fiber reinforced composites is desirable by the aircraft industry. Modular AFP heads with short, fixed tow path have the fundamental performance characteristics required to successfully and productively automate the production of these part families. Aircraft parts in this family include wing spars, stringers, and fuselage frames.

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.

Starting in 2003 Electroimpact began development on a comprehensive kinematic and compensation software package for machines with large envelopes. The software was first implemented on Electroimpact's Automatic Fiber Placement (AFP) equipment. Implementation became almost universal by 2005. By systematically collecting tracker measurements at various machine poses and then using this software to optimize the kinematic parameters of the machine, we are able to reliably achieve machine positional accuracy of approximately 2x the uncertainty of the measurements themselves. The goal of this paper is to document some of the features of this system and show the results of compensation in the hope that this method of machine compensation or similar versions will become mainstream.

A new portable floor drilling machine, the 767AFDE, has been designed with a focus on increased reach and speed, ease-of-use, and minimal weight. A 13-foot wide drilling span allows consolidation of 767 section 45 floor drilling into a single swath. A custom CNC interface simplifies machine operations and troubleshooting. Four servo-driven, air-cooled spindles allow high rate drilling through titanium and aluminum. An aluminum space frame optimized for high stiffness/weight ratio allows high speed operation while minimizing aircraft floor deflection. Bridge track tooling interfaces between the machine and the aircraft grid. A vacuum system, offline calibration plate, and transportation dolly complete the cell.

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.

Airbus UK was interested in a high-speed riveting machine cell that could automatically rivet over 30 different wing panels for a wide range of aircraft to fit in a limited floor space. Electroimpact was approached and proposed a Flexible, High Speed, Riveting Machine (HSRM). The resulting flexible riveting cell is 170 feet long and contains two flexible fixtures located end to end. Two fixtures allow manual work on one fixture while the machine is riveting on the second fixture. Each fixture can be quickly reconfigured to accommodate a broad range of Airbus panels. The system went into production on January 12, 2003 and has been extremely effective, riveting the first wing panel, a lower panel 1 for the A330-300 in only 5 days. This was one of the largest panels the cell was sized to accommodate. Anticipated process improvements will reduce the riveting time to just three days per panel.

Successfully riveting aerospace fatigue-rated structure (for instance, wing panels) requires achieving rivet interference between a minimum and a maximum value in a number of locations along the shank of the rivet. In unbalanced structure, where the skin is much thicker than the stringer, this can be particularly challenging, as achieving minimum interference at the exit of the skin (D2) can often be a problem without exceeding the maximum interference at the exit of the stringer (D4). Softer base materials and harder, higher-strength rivets can compound the problem, while standard manufacturing variations in hardness of part and rivet materials can cause repeatability issues in the process. This paper presents a solution that has been successfully implemented on a production commercial aircraft. The application of a special coating on the stringer side die dramatically reduces interference at the exit of the stringer, which in some instances resulted in a reduction of over 38%.

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.

Electroimpact and Lockheed Martin have developed an automated drilling and fastening system for C-130J aft fuselage panels. Numerous design and manufacturing challenges were addressed to incorporate the system into Lockheed Martin’s existing manufacturing paradigm and to adapt Electroimpact’s existing line of riveting machines for manufacture of these legacy aircraft parts. Challenges to automation included design of a very long yet sufficiently rigid and lightweight offset riveting anvil for fastening around deep circumferential frames, automated feeding of very short, “square” rivets in which the length is similar to the head diameter, creation of part programs and simulation models for legacy parts with no existing 3d manufacturing data, and crash protection for the aircraft part from machine collisions, given the uncertainties inherent in the model and the unique geometry of the aircraft parts.

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.

The handheld (HH) electromagnetic riveter (EMR) has proven to be an effective means of installing up to 7/16\mi diameter rivets in aircraft components. These devices are currently installing rivets on Boeing and Airbus planes all over the world. They are also very popular in China and Japan. However, there have always been difficulties with stringer access. A new version of lightweight driver with interchangeable offset tooling was created to alleviate this problem. In addition, a disposable plastic wedge has been incorporated at the base of the offset ram to prevent stringer damage during the recoil.