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System requirements and Interface Control Drawings (ICDs) make a variety of demands for MIL-STD-1553 remote terminals (RTs). Among these requirements are the need to ensure data integrity and sample data consistency, the need to perform bulk (multi-message) data transfers, and the need to offload the operation of the host CPU to the greatest degree possible. This latter requirement is reflected in such specifications as CPU spare bandwidth. The latest 1553 terminals provide a variety of choices for performing the different types of transfers. This paper provides a discussion of the hardware and software techniques for achieving these objectives. Three different schemes for RT subaddress memory management are presented: single message, circular buffer, and double buffered. For receive and transmit messages, these include fully synchronous single message transfers, asynchronous single message transfers, and multi-message transfers.

Contact the appropriate representative of the 2023 Noise and Vibration Conference and Exhibition.

The search for ever-lower emission technology for future generations of aircraft engines is actively progressing on both sides of the Atlantic. Tucked away on a modest-size stand at this year’s Farnborough International Airshow was a highly varied collection of unconventional engine technology displays – a clear indication of radical innovation already being investigated as a part of Ultimate, the European Horizon 2020 research and innovation project.

In part two of a two-part series, Richard Gardner discusses various aerospace propulsion innovations and continued work by aerospace engineers and scientists to advance aircraft engine technologies to increase efficiency and lower emissions.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

Dimensional Management (DM) is a methodology to predict and control the impact of variation on assembly from, fit, and function. Application of Dimensional Management tools and other modeling and simulation techniques are combined in a process called 3D Re-Engineering for application to existing production designs. Analytical techniques for predicting the impact of variation on assembly fit, and corresponding methods for controlling variation are presented, as used in a production environment for root cause corrective action on existing assembly fit problems. Assembly variation analysis is typically performed early in the product development phases, by coordinating datums, assembly sequences, assembly methods, and detail part tolerances across the product development team.

Coated refractory metals, coated and alloyed graphites, hafnium-tantalum alloys, refractory borides, and stabilized zirconias are considered for the 3600–4000 F high-velocity air environment. Only refractory borides and stabilized zirconias are indicated as offering long duration and reuse capabilities for such high-temperature utilization. Iridium, as coatings on substrates of either graphites or refractory metals, appears attractive for shorter times (less than 1 hr). Environmental evaluation and the need for a theoretical framework to enable the prediction of performance data for such materials are indicated to be major problems facing users and suppliers.

This handbook is intended to assist the user to understand the ANSI/EIA-649B standard principles and functions for Configuration Management (CM) and how to plan and implement effective CM. It provides CM implementation guidance for all users (CM professionals and practitioners within the commercial and industry communities, DoD, military service commands, and government activities (e.g., National Aeronautics and Space Administration (NASA), North Atlantic Treaty Organization (NATO)) with a variety of techniques and examples. Information about interfacing with other management systems and processes are included to ensure the principles and functions are applied in each phase of the life cycle for all product categories.

The 747 flight test certification program was initiated with the first flight of the No. 1 airplane on February 9, 1969. Five test airplanes were used in an intensive test program involving 1443 flight hr and 36-1/4 airplane months, with the last certification flight on December 23, 1969. Full type certification approval was granted by the FAA on December 30, 1969 after a total of 10-2/3 months of flight testing. These statistics compare very well with the original program estimates, which were based on Boeing's extensive experience with development and certification testing of commercial transport airplanes. The success of this test program was not due to any great advancements in flight test techniques specifically for the 747, but was due to the tried and proven test methods developed during past certification programs at Boeing. This is not meant to imply that some new methods were not used, but to emphasize that test techniques evolve with experience.

Shortly after World War II, as aircraft became more sophisticated and power-assist, flight-control functions became a requirement, hydraulic system operating pressures rose from the 1000 psi level to the 3000 psi level found on most aircraft today. Since then, 4000 psi systems have been developed for the U.S. Air Force XB-70 and B-1 bombers and a number of European aircraft including the tornado multirole combat aircraft and the Concorde supersonic transport. The V-22 Osprey incorporates a 5000 psi hydraulic system. The power levels of military aircraft hydraulic systems have continued to rise. This is primarily due to higher aerodynamic loading, combined with the increased hydraulic functions and operations of each new aircraft. At the same time, aircraft structures and wings have been getting smaller and thinner as mission requirements expand. Thus, internal physical space available for plumbing and components continues to decrease.

Shortly after World War II, as aircraft became more sophisticated and power-assist, flight-control functions became a requirement, hydraulic system operating pressures rose from the 1000 psi level to the 3000 psi level found on most aircraft today. Since then, 4000 psi systems have been developed for the U.S. Air Force XB-70 and B-1 bombers and a number of European aircraft including the tornado multirole combat aircraft and the Concorde supersonic transport. The V-22 Osprey incorporates a 5000 psi hydraulic system. The power levels of military aircraft hydraulic systems have continued to rise. This is primarily due to higher aerodynamic loading, combined with the increased hydraulic functions and operations of each new aircraft. At the same time, aircraft structures and wings have been getting smaller and thinner as mission requirements expand. Thus, internal physical space available for plumbing and components continues to decrease.

Affordable, reliable endo- and exoatmospheric transportation, for both the military and commercial sectors, grows in importance as the world grows smaller and space exploration and exploitation increasingly impact our daily lives. However, the impact of disciplinary, operational, and technological uncertainties inhibit the design of the requisite hypersonic vehicles, an inherently multidisciplinary and non-deterministic process. Without investigation, these components of design uncertainty undermine the designers’ decision-making confidence. In this paper, the authors propose a new probabilistic design method, using Bayesian Statistics techniques, which allows assessment of the impact of disciplinary uncertainty on the confidence in the design solution. The proposed development of a two-stage reusable launch vehicle configuration highlights the means to first quantify the fidelity of the disciplinary analysis tools utilized, then propagate such to the vehicle system level.

Thermal engineering has long been left out of the concurrent engineering environment dominated by CAD (computer aided design) and FEM (finite element method) software. Current tools attempt to force the thermal design process into an environment primarily created to support structural analysis, which results in inappropriate thermal models. As a result, many thermal engineers either build models “by hand” or use geometric user interfaces that are separate from and have little useful connection, if any, to CAD and FEM systems. This paper describes the development of a new thermal design environment called the Thermal Desktop. This system, while fully integrated into a neutral, low cost CAD system, and which utilitizes both FEM and FD methods, does not compromise the needs of the thermal engineer.