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An integration study was performed coupling an SP-100 reactor with either a Brayton or Stirling power conversion subsystem. A power level of 100 kWe was selected for the study. The power system was to be compatible with both the lunar and Mars surface environment and require no site preparation. In addition, the reactor was to have integral shielding and be completely self-contained, including its own auxiliary power for start-up. Initial reliability studies were performed to determine power conversion redundancy and engine module size. Previous studies were used to select the power conversion optimum operating conditions (ratio of hot-side temperature to cold-side temperature). Results of the study indicated that either the Brayton or Stirling power conversion subsystems could be integrated with the SP-100 reactor for either a lunar or Mars surface power application.

On January 14, 2004 President George W Bush outlined a new vision for NASA that has humans venturing back to the moon by 2020. With this ambitious goal, new tools and models have been developed to help define and predict the amount of space radiation astronauts will be exposed to during transit and habitation on the moon. A representative scenario is used that includes a trajectory from LEO to a Lunar Base, and simplified CAD models for the transit and habitat structures. For this study galactic cosmic rays, solar proton events, and trapped electron and proton environments are simulated using new dynamic environment models to generate energetic electron, and light and heavy ion fluences. Detailed calculations are presented to assess the human exposure for transit segments and surface stays.

Sundstrand has been investigating 270-Vdc/hybrid 115-Vac electrical power generating systems (EPGS) technology in preparation for meeting the electrical power generating system (EPGS) requirements for future aircraft (1). Systems such as the one being investigated are likely to be suitable for the More-Electric Aircraft (MEA) concepts presently under industry and military study. The present Sundstrand single-channel testbed is being further expanded to better understand the electrical system performance characteristics and power quality requirements of an MEA in which traditional mechanical subsystems are replaced by those of a “more-electric” nature. This paper presents the most recent Sundstrand 270-Vdc system transient performance data, and describes the modifications being made to the 270-Vdc/hybrid 115-Vac testbed.

Different Airbus Helicopters main rotor blade profiles were tested in different icing wind tunnels and for different icing conditions. One of the objectives of the accretion tests was to validate the use of 2D icing scaling laws established for fixed wing aircraft on helicopter blade profiles. Therefore, ice shapes resulting from tests with the same icing similarity parameters are compared to each other allowing the assessment of icing scaling laws for helicopter applications. This paper presents the icing scaling laws used at Airbus Helicopters on blade profiles, the different test set ups and test models and it presents the comparison of the ice shapes collected during the icing wind tunnel test campaigns.

A helicopter blade profile was tested in the DGA Aero-engine Testing's icing altitude test facility S1 in Saclay, France during the winter of 2013/2014. The airfoil was a helicopter main rotor OA312 blade profile made out of composite material and with a metallic erosion shield. Dry air and ice accretion tests have been performed in order to assess the iced airfoil's aerodynamic behaviour. Several icing conditions were tested up through Mach numbers around 0.6. This paper presents the test setup, the test model and some of the test results. The test results presented in this paper include the ice shapes generated as well as dry air and iced airfoil lift and drag curves (polars) which were obtained with the real ice shapes on the airfoil.

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 scope of this Standard is the definition of the response of a numerically controlled machine to a valid sequence of records made up of 32 bit binary words or ASCII text strings. The Standard defines the structure of these records and of the 32 bit binary words or ASCII text strings which make up the records. This standard addresses the control of machines capable of performing 2, 3, 4, and 5 axis motion of an active tool (mill, laser, pen, etc.) relative to a part, and those capable of 2 and 4 axis tool motion relative to a rotating part (turning machines), including parallel tool slide sets capable of concurrent (merged) motion.

A 3D computer model named AIPAC (Aircraft Ice Protection Analysis Code) suitable for thermal ice protection system parametric studies has been developed. It was derived from HASPAC, which is a 2D anti-icing model developed at Wichita State University in 2010. AIPAC is based on the finite volumes method and, similarly to HASPAC, combines a commercial Navier-Stokes flow solver with a Messinger model based thermodynamic analysis that applies internal and external flow heat transfer coefficients, pressure distribution, wall shear stress and water catch to compute wing leading edge skin temperatures, thin water flow distribution, and the location, extent and rate of icing. In addition, AIPAC was built using a transient formulation for the airfoil wall and with the capability of extruding a 3D surface grid into a volumetric grid so that a layer of ice can be added to the computational domain.

The need to improve quality while reducing cost in aerospace manufacturing is requiring new manufacturing methods and processes. Advanced technologies, such as 3D Image Metrology, offer great potential to lean manufacturing, if properly integrated into the production process. Over the last years 3D Image Metrology has developed a level of performance, which make it ideally suited for this purpose. These capabilities include the automatic in-process inspection of tools and parts before machining, machine control for highly accurate positioning during the machining operation, and in-process inspection during machining. This offers jig-less assembly, lower inventory, faster part throughput, and many more advantages.

The in-flight ice accretion simulations are typically performed using a quasi-steady formulation through a multi-step approach. As the ice grows, the geometry changes, and an adaptation of the fluid volume mesh used by the airflow and droplet-trajectory solver is required. Re-meshing or mesh deformation are generally employed to do that. The geometries formed are often complex ice shapes increasing the difficulty of the re-meshing process, especially in three-dimensional simulations. Consequently, difficulties are encountered when trying to automate the process. Contrary to the usual body-fitted mesh approach, the use of immersed boundary methods (IBMs) allows solving, or greatly reducing, this problem by removing the mesh update, facilitating the global automation of the simulation. In the following paper, an approach to perform the airflow and droplet trajectory calculations for three-dimensional simulations is presented. This framework utilizes only immersed boundary methods.

Vertical-Junction-Field-Effect-Transistors (VJFETs) are currently the most mature SiC devices for high power/temperature switching. High-voltage VJFETs are typically designed normally-on to ensure voltage control operation at high current-gain. However, to exploit the high voltage/temperature capabilities of VJFETs in a normally-off high-current voltage-controlled switch, high-voltage normally-on and low-voltage normally-off VJFETs were connected in the cascode configuration. In this paper, we review the high temperature DC characteristics of VJFETs and 1200 V normally-off cascode switches. The measured parameter shifts in the 25°C to 300°C temperature range are in excellent agreement with theory, confirming fabrication of robust SiC VJFETs and cascode switches.

New approaches to problems such as noise, temperature control of accessories and equipment in the nacelle, as well as improved safety features, are necessary in a modern high by-pass engine installation. The means of supporting the engine, cowling design, and maintainability features combine to improve the state of the art that a more economic airplane will result.

The 757/767 Flight Management System provides the initial operational implementation of an integrated guidance, control and display equipments based upon digital technology for commercial transport airplanes. The applied equipments are based upon the new ARINC 700 series characteristics developed by the Industry over the past five years. These characteristics were developed on the basis of limited operational experience with selected elements of the system and upon R&D efforts within the Industry. The System features automatic/manual flight profiles for optimum economics, all weather landing including rollout guidance, electronic primary flight instruments based on color (shadow mask) CRTs, inertial attitude/velocity reference based upon laser gyros, improved caution/warning and other improved performance/functional features. The system also provides significant improvements in line and shop maintenance features.

The Automated Spar Assembly Tool (ASAT II) at the Everett, Washington, 777 Boeing manufacturing facility could be the largest automated fastening cell in the commercial aircraft industry. Based on the success of the ASAT I, Boeing's 767 spar assembly tool, the 285-foot long ASAT II cell was needed to accurately position and fasten the major spar components (chords and web), then locate and fasten over 100 components (ribposts and stiffeners) to assemble the 777 forward and rear wing spars. From its inception in 1990 to the first drilled hole in January 1993 and through two years of spar production, the more advanced ASAT II has proven to be a greater success than even its 767 ASAT I predecessor. This massive automated fastening system consistently provides accurate hole preparation, inspection, and installation of three fastener types ranging from 3/16 inches to 7/16 inches in diameter.

This paper describes the wing and engine ice protection system, used on all 777 aircraft. The 777 ice protection system is unique in two ways: it has an advanced control system which minimizes aircraft power consumption. In addition, the system was procured by the prime contractor, Boeing, as a fully integrated subsystem from a single supplier.

In the course of CRYOSYSTEM phase B (development phase) financed by the European Space Agency, AIR LIQUIDE (France) and Astrium Space Infrastructure (Germany) have developed an optimized design of a −183°C freezer to be used on board the International Space Station for the freezing and storage of biological samples. The CRYOSYSTEM facility consists of the following main elements: - the CRYORACK, an outfitted standard payload rack (ISPR) accommodating up to three identical Vial Freezers - the Vial Freezer, a dewar vessel capable of fast and ultra-rapid freezing, and storing up to approximately 900 vials below −183°C; the dewar is cooled by a Stirling machine producing > 6 W at 90 K. The Vial Freezer is operational while accommodated in the CRYORACK or attached to the Life Science Glovebox (LSG). One CRYORACK will remain permanently on-orbit for several years while four Vial Freezers and two additional CRYORACKs support the cyclic upload/download of samples.

In the frame of the CRYOSYSTEM A-phase study financed by the European Space Agency, AIR LIQUIDE (France) and ORBITAL HYDRAULIC-BREMEN (Germany) have been studying a -183°C freezer to be used on-board the International Space Station for freezing and storing biological samples.

U S Army tactical vehicles are equipped with a wide range of electrical and electronic equipment to support a variety of missions. This equipment typically requires AC input power with varying voltage, power and phasing requirements. Presently, separate inverters with different voltage, power, and phase ratings are necessary to power the equipment, which imposes maintenance and support problems during field deployments. Avionic Instruments Inc. has developed a scalable inverter system that operates from 28V vehicular power and provides outputs that can easily be configured for a variety of load requirements.