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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.

Low rate initial production of the 777X flight control surfaces and wing edges has been underway at the Boeing St. Louis site since early 2017. Drilling, inspection, and temporary fastening tasks are performed by automated multi-function robotic systems supplied by Electroimpact. On the heels of the successful implementation of the initial four (4) systems, Phases II and III are underway to meet increasing production demands with three (3) and four (4) new cells coming online, respectively. Assemblies are dedicated to particular cells for higher-rate production, while all systems are designed for commonality offering strategic backup capability. Safe operation and equipment density are optimized through the use of electronic safeguards. New time-saving process capabilities allow for one-up drilling, hole inspection, fastening, fastener inspection, and stem shaving.

Boeing needed a process to replace hand drilling for floor panel holes and galley and lavatory mounting locator holes in the floor grid of the completed 737 fuselage. Electroimpact developed a process, and the 737 AFDE machine, that is a substantial improvement over existing technology. It provides full CNC control, quick reconfiguration of hole patterns, fast drilling of up to 3000 holes in one 8-hour shift, drills both titanium and aluminum and works inside the fuselage.

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.

In traditional manufacturing when a product (such as a wing panel or wing spar) was designed the manufacturing process to build the product was of little consideration. The design of the product was manually created on a 2 dimensional drawing without investigation of what data could be included to achieve a more productive automated assembly (fastening) system. Even less development was expended on integration of part design and manufacturing to improve downstream processes and product quality. Today, every avenue of optimization and continuous quality improvement must be explored to create a lean manufacturing environment that produces low costs with high productivity at all levels. This paper will describe design and manufacturing engineering processes used to streamline creation of machine control data for automated fastening systems. Applying design for manufacturing concepts and automation of upstream processes to provide significant benefits in the production environment.

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.

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.

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.

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.

Eight SUMMA passivated sampling canisters were shipped to the Russian Space Station Mir in February of 1995 to assess ambient trace contaminant concentrations. Prior to flight, the canisters were injected with isotope labeled surrogates and internal standards to measure potential negative impacts on measurement accuracy caused by the trip environmental conditions of launch and return. Three duplicate canister samples were collected in parallel with Russian sorbent samples to acquire data for comparative purposes. A total of 32 target and 13 non-target volatile compounds were detected in each of the samples analyzed. The concentrations of the compounds remained relatively consistent for the three sampling events, and all of the concentrations of detected contaminants were well below both US and Russian Spacecraft Maximum Allowable Concentrations (SMAC). Five different fluorocarbons were consistently detected at relatively high concentrations.

The use of portable automated equipment has increased in recent years with the introduction of flex track, crawling robots, and other innovative machine configurations. Portable automation technologies such as these lower infrastructure costs by minimizing factory floor space requirements and foundation expenses. Portable automation permits a higher density of automated equipment to be used adjacent to aircraft during assembly. This equipment also allows concurrent work in close proximity to automated processes, promotes flexibility for changes in rate, build plan, and floor space requirements throughout the life of an airplane program. This flexibility presents challenges that were not encountered with traditional fixed machine drilling centers. The work zone surrounding portable machines is relatively small, requiring additional setup time to relocate and position machines near the airframe.

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.

Determining local ice crystal icing concentration factors in the region of the forward fuselage is critical for setting the Total Water Content levels for air data probe qualification testing. Simulation, modeling, and testing techniques for this concentration-factor phenomenon are still in their infancy, and there is currently not a significant amount of this type of analysis in the literature. A representative, 3D analysis was conducted using transport airplane geometry and flight conditions that explored the sensitivities resulting from parametric changes to flight and ice crystal icing conditions, particle modeling parameters, and bouncing effects.

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.

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 Turret Head Fastening System is an enhancement of current three position “C-frame” wing riveting machines. It was designed and built by Boeing as a fully instrumented research machine in 1991 for the 777 Airplane, and as a potential retrofit package for conventional drill, rivet, shave wing assembly machines. It was designed to automatically install rivets and bolts and perform the required hole preparation prior to fastener installation. In its current form, it will clamp a panel; and then as the fastener requires, drill, coldwork, ream, countersink the hole; inspect the hole; apply sealant when required; install threaded fasteners or rivets; torque the nut, swage the collar or upset the rivet as required; shave the rivet to ensure flushness; and finally unclamp the part - all within the current working envelope of a drill, rivet shave machine. Currently, switching from rivets to bolts requires a 5 minute tool change.