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Titanium is a difficult material to fabricate into complex configurations. There is several elevated temperature forming processes available to produce titanium components for aerospace applications. The processes to be discussed are Superplastic Forming (SPF), hot forming and creep forming. SPF uses a tool that contains the required configuration and seals around the periphery so inert gas pressure can be used to form the material. Of the processes to be discussed, this is the one that can produce the most complex shapes containing the tightest radii. A variation of the process combines an SPF operation with diffusion bonding (SPF/DB) of two or more pieces of titanium together to produce integrally stiffened structure containing very few fasteners. Another process for shaping titanium is hot forming. In this process, matched metal tools, offset by the thickness of the starting material, are used to form the part contour at elevated temperature.

Current methods of life cycle assessment (LCA) include input-output (IO) models and process-based LCA. These methods either require excessive effort and time to reach a conclusion (process LCA) or do not adequately model how a change in a product's design will affect the environmental footprint (IO LCA). A variation of process-based LCA developed specifically for aircraft is presented in this study. A tool implementing this LCA, “qUWick,” is rapid and easily applicable to multi-disciplinary design optimization of aircraft. Models developed for the material production, manufacturing, usage, and end-of-life of an aircraft are examined. Outputs of qUWick are discussed for future air vehicles. When compared to process LCAs with similar boundaries, qUWick gives similar results, however qUWick models several stages of an aircraft's life cycle more accurately than other aircraft process-based LCAs.

The Boeing Company is striving to improve quality and reduce defects and injuries through the implementation of lightweight “Right Sized” automated drill and fasten equipment. This has lead to the factory adopting Boeing developed and supplier built flex track drill and countersink machines for drilling fuselage circumferential joins, wing panel to spar and wing splice stringers. The natural evolution of this technology is the addition of fastener installation to enable One Up Assembly. The critical component of One Up Assembly is keeping the joint squeezed tightly together to prevent burrs and debris at the interface. Traditionally this is done by two-sided machines providing concentric clamp up around the hole while it is being drilled. It was proposed that for stiff structure, the joint could be held together by beginning adjacent to a tack fastener, and assemble the joint sequentially using the adjacent hole clamp up from the previous hole to keep the joint clamped up.

Boeing has relied upon the 767 ASAT (ASAT1) since 1983 to fasten the chords, stiffeners and rib posts to the web of the four 767 wing spars. The machine was originally commissioned with a Terra five axis CNC control. The Terra company went out of business and the controls were replaced with a custom DOS application in 1990. These are now hard to support so Boeing solicited proposals. Electroimpact proposed to retrofit with a Fanuc 31I CNC, and in addition, to replace all associated sensors, cables and feedback systems. This work is now complete on two of the four machines. Both left front and right front are in production with the new CNC control.

One of the most common damages occurred found on commercial airframes are dents and gouges. The usual repair for these damages includes installation of metallic doublers with rivets or with hi-loks. Sometimes these doublers are of complex design, because of multiple angles of the original damaged skin. Many times the damages are in hard to reach areas. In these cases the traditional metallic doubler repairs are not only time consuming and but also expensive. As the numerous holes are be drilled through the original structure, its fatigue life is adversely affected. For airline operators, time is valuable and they cannot afford to lose revenue by spending longer time for repairs. The use of bonded composite doublers offers the airframe manufacturers and aircraft repair facilities an alternative repair process that alleviates the abovementioned concerns.

Parallel kinematic mechanisms (PKMs) offer advantages of high stiffness to mass ratios, greater potential for accuracy and repeatability, and lower cost when compared to traditional assembly machines. Because of this, there is a strong interest in using PKMs for aerospace assembly and joining operations. This paper looks at the calibration of a prototype Gantry TAU robot by extending the higher-order implicit loop calibration techniques developed for serial link mechanisms to parallel link mechanisms. The kinematic model is based on the geometric model proposed by Dressler et al., augmented with a cubic spline error model of the motion errors for each of the three translation actuators resulting in 185 parameters. Measurements are taken with a 6-DOF laser tracker, and the kinematic parameters are solved as the maximum likelihood parameter estimate.

Engineering plastics are now available for use on lightly loaded aircraft structure. These materials have excellent cost benefits as well as producibility benefits over their hand laidup predecessors. They are especially useful in the strut and nacelle areas where many of the fairings are attached for aerodynamic purposes only and may have rather complicated contours. In addition to lower costs, the manufacturing process is consistent, unlike hand laidup parts, which often require rework. In the strut and nacelle area one of the major requirements for all parts is sonic durability. This paper is intended to explain the test setup and test procedure for sonic testing of thermoplastics and thermosets and the results of the testing up to this point. Included in this explanation will be the assumptions made, the test setup, results of the testing and conclusions drawn from the testing.

International Space Station (ISS) will provide Low Temperature (LT), and Moderate Temperature (MT) Internal Thermal Control System (ITCS) coolant to payloads and other users. LT ITCS delivers 38° to 42° F coolant MT ITCS delivers 62° to 65° F coolant. By using LT ITCS cabin air, dew point is controlled by the Thermal and Humidity Control (THC) subsystem to be 49° to 55° F when manned. Since the dew point temperature is above the LT ITCS nominal temperature, any components that have this coolant in them can be expected to condense moisture on their surfaces. The components that are affected are many. This paper, however, is concerned only with the lines and Quick Disconnects (QDs) that are a part of the total ITCS system.

Some of the common methods of reliability prediction utilizing calendar or lot size dependence and various "k" factors for complexity, end use, product family, and environment are briefly reviewed. These techniques, although sometimes accurate and simple, do not provide adequate reliability tradeoff information and do not fully treat the effects of vendor variability and improvements in the state-of-the-art. From these techniques it is frequently difficult to understand causes of observed failure rates and to determine what can be done to achieve cost-effective reliability. One method of alleviating these objections is to derive a model based on microcircuit failure mode and mechanism knowledge. The current status of microcircuit failure knowledge is reviewed. Considerable use is made of data which has been acquired at very high stress levels and the relationship between this data and end use data is discussed.

A new look at tactical combat V/STOL design and utility as affected by emerging technology and mission concepts is given in this paper. History has shown that a certain level of useful load fraction must be attained before an airplane system can be considered operationally successful. Technology trends reviewed in this paper suggest that the time is here or at least near for V/STOL tactical aircraft to achieve a truly viable useful load fraction. Propulsion, structure, and controls technologies will contribute to the success of the tactical V/STOL system. In addition, aerodynamic technology as related to interference effects in hover and transition, and as required for efficient supersonic cruise and combat, significantly impacts the design solution. A unique approach to system design risk assessment is described with results giving technology leverage as a function of design options.

The term “3 inch ice shapes” has assumed numerous definitions throughout the years. At times it has been used to generally characterize large glaze ice accretions on the major aerodynamic surfaces (wing, horizontal stabilizer, vertical stabilizer) for evaluating aerodynamic performance and handling qualities after a prolonged icing encounter. It has also been used as a more direct criterion while determining or enforcing sectional ice shape characteristics such as the maximum pinnacle height. It is the authors’ observation that over the years, the interpretation and application of this term has evolved and is now broadly misunderstood. Compounding the situation is, at present, a seemingly contradictory set of guidance among (and even within) the various international regulatory agencies resulting in an ambiguous set of expectations for design and certification specialists.

The re-invention of the global aviation industry is well underway. This dramatic change is being achieved through the use of emergent technology to facilitate a progressive disintermediation of traditional aviation business solutions and services. This progressive disintermediation will continue unabated as this technology is adopted and deployed within the aviation industry. The challenge and opportunity is to whom will lead this re-invention and how will it be accomplished. The integrated use of rapidly evolving technology (Blockchain, IoT, Artificial Intelligence, 5G Cellular Technology and Mobile Edge Computing) is facilitating an integrated more industry cooperative approach enabling this progressive disintermediation.

With the increasing usage of composites for aerodynamic surfaces, the use of bonded composite repair processes are becoming more common. The repair process remains a largely manual process, with repair technicians scarfing or stepping, tracing the plies, fabricating repair patches and finally bonding the patch. The patch fabrication process becomes increasingly tedious and tiring due to cutting and tracing of each individual ply twice for thermal surveying and the final repair patch. We have developed a system that can replace the tracing and cutting components of the fabrication process using low cost, commercial off the shelf (COTS) tools. We present the ply boundary extraction method used and detail the nesting algorithm used to produce the final plies. Our software is benchmarked against the manual process with a list of successfully cut materials using a low cost fabric cutter with a steel drag blade.

Flight in icing for transport category aircraft certification presents a particularly challenging set of considerations to establish adequate safety commensurate with the associated risk while balancing design complexity and efficiency. A review highlighting important aspects of the regulatory evolution and guiding principles for flight in icing certification is presented, including the current standards and recent rulemaking activity.

The Particular Risks Assessment Document (PRA) is the compendium of the assessments accomplished during the development of a new airplane that relate to threats to the airplane from the outside environment (e.g. birdstrike, lightning, hail) and threats to the systems from events originating in other systems (e.g. rotorburst, flailing shafts, tire and wheel burst). These assessments are accomplished to ensure the robustness of the design to survive these threats. An extensive list of threats is developed and teams are formed to evaluate each of them. The results of these studies are collated into a document that provides a single point reference for the new airplane with regard to its ability to survive all known external threats. If PRAs have been accomplished on previous programs they can be used as a starting point for the new assessment, then the systems are reevaluated against the new design and differences created by new design features need to be added to the list.

Over the next twenty years, the role and contributions of successfully managed projects will continue to grow in importance to aerospace organizations, especially considering the demands of emerging markets. The accompanying challenges will be how to effectively reduce product and process cost where known (incremental) and unknown (transformational) technological innovation is required. Managing Aerospace Projects brings together ten seminal SAE technical papers that support the vision of a more holistic and integrated approach to highly complex projects. Using the concept of project management levers, Dr.

Integrated Vehicle Health Management (IVHM) is the unified capability of a system of systems (SoS) to assess the current or future state of the member system health, and integrate it within a framework of available resources and operational demand. As systems complexities have increased, so have system support costs, driven by more frequent and often enigmatic subsystem failures. IVHM strategies can be used to mitigate these issues by taking a Systems of Systems view. Combined with advanced decision support methods, this approach can be used to more effectively predict, isolate, schedule, and repair failed subsystems, reducing platform support costs and minimizing platform down time. Integrated Vehicle Health Management- System of Systems Integration brings together ten seminal SAE technical papers addressing the challenges and solutions to maintaining highly complex vehicles.