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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.

Abstract While the design of nozzles for diatomic gases is very well established and covered by published works, the case of a diatomic gas dissociating to monatomic along a nozzle is a novel subject that needs a proper mathematical description. These novel studies are relevant to the definition of nozzles for gas-core Nuclear Thermal Rockets (NTR) that are receiving increased attention for the potential advantages they may deliver versus current generation rockets. The article thus reviews the design of the nozzles of gas-core NTR that use hydrogen as the propellant. Propellant temperatures are expected to reach 9,000-15,000 K. Above 1500 K, hydrogen begins to dissociate at low pressures, and around 3000 K dissociation also occurs at high pressures. At a given temperature, the lower the gas pressure the more molecules dissociate, and H2 → H + H. The properties of the gas are a function of the mass fractions of diatomic and monatomic hydrogen x H2 and x H = 1 − x H2.

Abstract It is reasonable to use a two-phase heat transfer loop (TPL) in a thermal control system (TCS) of spacecraft with large heat dissipation. One of the key elements of TPL is a heat-controlled accumulator (HCA). The HCA represents a volume which is filled with vapor and liquid of a single working fluid without bellows. The pressure in a HCA is controlled by the heater. The heat and mass transfer processes in the HCA can proceed with a significant nonequilibrium. This has implications on the regulation of TPL. This article presents a mathematical model of nonequilibrium heat and mass transfer processes in an HCA for microgravity conditions. The model uses the equations of mass and energy conservation separately for the vapor and liquid phases. Interfacial heat and mass transfer is also taken into account. It proposes to use the convective component k for the level of nonequilibrium evaluation.

This document outlines the current state of the art in the understanding of gas in solution in shock absorber oils in unseperated shock absorbers. A literature review, overview of Henry's law, Henry's law coefficients for known gas and oil couples, in-service operational problems, lessons learned, and potential future work will be discussed in the document.

This document outlines historical systems which have used the landing gear as a sensor or installation point for full aircraft weight and balance systems. A number of systems have been developed, installed, certified, and placed in service but few systems remain in regular use. The document will capture the history of these systems, reasons (where known) for their withdrawal from service, and lessons learned.

This document will outline existing best practices in the instrumentation of landing gears for in-service operation (including flight test, operational loads monitoring, etc.).

This report will document Runway Condition Monitoring systems that provide information intended to reduce or eliminate aircraft runway excursions or overruns that may occur as a result of poor runway conditions.

This document describes the approaches taken to define safe-life limits for the management of fatigue in landing gear structures, and the substantiation of those limits through full-scale fatigue testing. The safe-life scatter factors considered in a range of military and civil regulatory standards are also reviewed.

The scope of the test method is to provide stakeholders including fluid manufacturers, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This test is designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions.

This document was requested by the FAA to provide a technical update of TSO-C26d to address Electric Brake Actuation, standardize with TSO-C135a and address any remaining concerns with the current technical requirements in AIR5381.

This SAE Aerospace Standard (AS) prescribes the Minimum Performance Standards (MPS) for environmental conditions that wheel, brake, and wheel and brake assemblies to be used on aircraft certificated under 14 CFR Parts 23, 25, 27, and 29. The environmental requirements in this document shall be used in conjunction with other MPS defined in Technical Standard Orders for the applicable equipment.

This specification covers one type of aluminum bronze in the form of rods, bars, forgings, and forging stock.

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 scope of this document is limited to encompass terminology, symbols, performance criteria and certain elementary test methods reflecting the current status of the technology.

The scope of this document is limited to encompass terminology, symbols, performance criteria and certain elementary test methods reflecting the current status of the technology.

This standard establishes uniform test methods for testing electrical connectors.

This document has been formulated as a suggested guide in assisting EIA Engineering Department Panels and JEDEC Councils in cooperating with the Defense Department and other Federal agencies in the preparation of suggested reliability requirements for various types of electronic products as part of a program designed to enhance the reliability of defense and related equipment. The document is to be followed merely as a guide and is not intended to limit technical groups in the consideration of the factors to be taken into account in the development of reliability specifications for recommendation to the Government.