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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.

This collection of technical papers covers advanced portable semi-automated drilling and fastening systems and portable crawler/flex track systems; assembly methodologies and advanced assembly fixtures and tooling; composites assembly and fastening; composte/heavy metal drilling and assembly; large component assembly, sub-assembly, major section join and final assembly; robotic applications in drilling, fastening and assembly; and advancements in drill bit, temporary and permanent fastening technology.

Abstract Constant area section length downstream to the fuel injection point is a crucial dimension of scramjet duct geometry. It has a major contribution in creating the maximum effective pressure inside the combustor that is required for propulsion. The length is limited by the thermal choking phenomenon, which occurs when heat is added in a flow through constant area duct. As per theory, to avoid thermal choking the constant area section length depends upon the inlet conditions and the rate of heat addition. The complexity related to mixing and combustion process inside the supersonic stream makes it difficult to predict the rate of heat addition and in turn the length. Recent efforts of simulating the reacting flow inside scramjet combustors are encouraging and can be useful in this regard. The presented work attempts to use simulation results of scramjet combustion for predicting the constant area section length for a typical scramjet combustor.

Abstract Jet engine hot parts (e.g., jet nozzle) are a crucial source of aircraft’s infrared (IR) signature from the rearview, in 1.9-2.9 μm and 3-5 μm bands. The exhaust nozzle design used in a jet aircraft affects its performance and IR signature (which is also affected just by performance) from the engine layout. For supersonic aircraft (typically for M ∞ > 1.5), a converging-diverging (C-D) nozzle is preferred over a convergent nozzle for optimum performance. The diverging section of the C-D nozzle has a full range of visibility from the rearview; hence, it was not considered a prudent choice for low IR observability. This theoretical study compares the IR signature of the C-D nozzle with that of the convergent nozzle from the rearview in 1.9-2.9 μm and 3-5 μm bands for the same thrust.

To inform users on proper use, procedures and common errors when using electronic compensation for tooling on horizontal and vertical balancing machines

Provide guidance on how balance machine vector data is captured and reported. Provide an understanding of how to transform balance machine vector data to alternate locations. Provide guidance on how vector imbalances may be used to evaluate and diagnose balance process performance.

Set forth dimensions and specifications for Nickel Alloy N07718 100 deg csk 0.114” to 0.3750” diameter screws with AS6305 recess.

This document establishes process parameters for gas turbine rotor balancing. Adherence to the recommendations made herein will facilitate attainment of the usually high degree of accuracy and precision required for jet engine rotor balance.

The scope of these standards will relate to single-axis moment scales only. Topics covered include dimensional characteristics of single-axis moment scale interfaces, general tooling requirements, scale and tooling accuracy, and display instrument accuracy requirements. Additionally, general guidelines for qualification of equipment and tooling are included, as are general requirements for single-axis blade distribution software.

A guide to maintenance procedures in test cells. A suggested equipment monitoring and/or inspections to reduce the probability of unanticipated failures and associated test cell down time. Guidelines for using typically available data acquisition capabilities in a test cell are provided to utilize normally available trending capability to monitor the testing equipment in addition to using these tools for the usual monitoring of the test article. For the common types of test cells (turboshaft, turboprop, turbojet, and turbofan) test facilities, lists of typical systems with their associated components are provided with suggested inspection intervals and key items to look for in the inspection. A template risk assessment form is provided to facilitate the customization of the assessment of the test cell components to help predict recommended spares.

This new Aerospace Recommended Practice will serve as a practical resource that offers guidance to both the machine operator and Process Engineer for isolating the source(s) of non-repeatability in measured unbalance data. The content of this standard addresses: • Vertical Dynamic Machine Capability to achieve the specified unbalance tolerances and repeat within those tolerances • Tooling Capability to repeat within the specified unbalance tolerances • Rotor characteristics that may preclude repeating within the required unbalance tolerances.

This specification covers honeycomb core made of polyamide paper sheets in a non-hexagonal, flexible cell configuration and supplied in the form of blocks, slices, and ordered shapes.

This specification covers honeycomb core made of polyamide paper sheets in a non-hexagonal, flexible cell configuration and supplied in the form of blocks, slices, and ordered shapes.

The report shows how the methodology of measurement uncertainty can usefully be applied to test programs in order to optimize resources and save money. In doing so, it stresses the importance of integrating the generation of the Defined Measurement Process into more conventional project management techniques to create a Test Plan that allows accurate estimation of resources and trouble-free execution of the actual test. Finally, the report describes the need for post-test review and the importance of recycling lessons learned for the next project.

The effectiveness of serial link articulated robots in aerospace drilling and fastening is largely limited by positional accuracy. Unguided production robotic systems are practically limited to +/-0.5mm, whereas the majority of aerospace applications call for tolerances in the +/-0.25mm range. The precision with which holes are placed on an aircraft structure is affected by two main criteria; the volumetric accuracy of the positioner, and how the system is affected when an external load is applied. Production use and testing of off-the-shelf robots has highlighted the major contributor to reduced stiffness and accuracy as being error ahead of the joint position feedback such as backlash and belt stretch. These factors affect the omni-directional repeatability, thus limiting accuracy, and also contribute to deflection of the tool point when process forces are applied.

The paper explains the compact fixturing based on magneto-rheological (MR) fluids that have been designed and validated for aeronautic stringers milling. The MR fluid based tooling developed is flexible and reconfigurable as it can be adapted to different profile's lengths and sections and it is able to fix compliant workpieces without reference faces as the MR fluid adapts to the outer shape of each profile. The MR fluid based tooling is suitable to hold non-magnetic materials such as aluminum and also materials that do not admit high clamping forces, such as titanium, because they will appear as deformation after machining due to the memory effect of titanium. The MR fluid based tooling has been tested in a machine environment under real machining conditions and promising results have been obtained.