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Integrating the seemingly divergent objectives of aircraft seat configuration is a difficult task. Aircraft manufacturers look to design seats to maximize customer satisfaction and in-flight safety, but these objectives can conflict with the profit motive of airline companies. In order to boost revenue by increasing the number of passengers per aircraft, airline companies may increase seat height and decrease seat pitch. This results in disaccommodation of a greater percentage of the passenger population and is a reason for rising customer dissatisfaction. This paper describes an effort to bridge this gap by incorporating digital human models, layout optimization, and a profit-maximizing constraint into the aircraft seat design problem. A simplified aircraft seat design experiment is conceptualized and its results are extrapolated to an airline passenger population.

A Lunar habitat will be highly sensored and generate large amounts of data or telemetry. For this data to be useful to humans monitoring these systems and to automated algorithms controlling these systems it will need to be converted into more abstract data. This abstracted data will reflect the trends, states and characteristics of the systems and their environments. Currently this data abstraction process is manual and ad hoc. We are developing a Data Abstraction Architecture (DAA) that allows engineers to design software processes that iteratively convert habitat data into higher and higher levels of abstraction. The DAA is a series of mathematical or logical transformations of telemetry data to provide appropriate inputs from a hardware system to a hardware system controller, system engineer, or crew. The DAA also formalizes the relationships between data and control and the relationships between the data themselves.

The Moon is composed of a variety of oxygen-bearing minerals, providing a virtually unlimited quantity of raw material that can be processed to produce oxygen. One attractive method to extract oxygen from the lunar regolith is the carbothermal reduction process. This paper discusses recent development work conducted through the PILOT project under the NASA OPTIMA program. The OPTIMA test program utilizes a modular technology suite of ISRU excavation, oxygen extraction, oxygen storage, and oxygen distribution hardware sized to be consistent with the draft Constellation requirements for oxygen extraction from the regolith to support the early lunar outpost (1 MT O2/year).

The system dependency analysis for complex aircraft systems is a model-based methodology and tool for analyzing availability and minimum acceptable control requirements for failures or event scenarios to support the aircraft and system safety analyses (SAE ARP4761) required to show compliance to 14CFR/CS §25.1309, §25.671 and other, related requirements. Aspects of the system such as functional interaction and dependencies to supply systems, physical items (equipment, wiring and tubing) and installation aspects are included in the analysis. This paper describes additional steps to enable the search for potential common cause failure conditions for the system of interest or airplane level systems based on the system model. Common cause analysis (CCA) procedures using the system dependency analysis rely on a systematic and checklist-based approach to determine potential common cause failure conditions.

The system dependency analysis for complex aircraft systems is a model-based methodology and tool for analyzing availability and minimum acceptable control requirements for failures or event scenarios to support the aircraft and system safety analyses (SAE ARP4761) required to show compliance to 14CFR/CS §25.1309, §25.671 and others. Aspects of the system such as functional interaction and dependencies to supply systems, physical items (equipment, wiring and tubing) and installation aspects are included in the analysis. The SAE paper “System Dependency Analysis for Complex Aircraft Systems” (2007-01-3852) describes the modeling approach and the analysis of system dependencies supporting the aircraft and system safety analyses. This paper provides examples for using the system dependency analysis to support the common cause analyses (SAE ARP4761) for complex aircraft systems.

Scope of the DRESS project is to research, develop and validate a distributed and redundant electrical steering system technology for an aircraft nose landing gear. The new system aims to: • reduce system weight at aircraft level, replacing the current hydraulic actuation system with an electric one. • improve aircraft safety, achieving higher system redundancy levels compared to the current technology capabilities. This paper presents an outline of different activities occurring in the DRESS project and also shows preliminary results of the new system performance.

The presented paper introduces the new software complex aimed at simulation of the riveting process as applied to aircraft parts. The software complex implements the novel mathematical model based on minimization of the potential energy. The paper gives the detailed description of the mathematical model and particularizes the main features of the software. The physical and numerical tests aimed at validation of the software are also described in the paper.

Manual drilling and Lockbolt installation in carbon fiber structures is a labor intensive process. To reduce man hour requirements while concurrently improving throughput and process quality levels BROETJE-Automation developed a gantry positioning system with high performance multi-function end effectors for this application. This paper presents a unique solution featuring fully automated drilling and Lockbolt installation (inclusive of automated collar installation) for the vertical tail plane (vertical stabilizer) of large commercial aircraft. A flexible and reconfigurable assembly jig facilitates high access of the end effectors and increases the equipment efficiency. The described system fulfils the demand for affordable yet flexible precision manufacturing with the capacity to handle different aircraft model panels within the work envelope.

Due to the conventional autoclaving of pre-impregnated materials causes high costs in the production of carbon fibre structures, new injection methods have become more and more relevant. The research project “CFK-Tex” focuses on the automated handling and processing of preforms out of dry carbon fibre textiles. Regarding the advantages in quality improvement and process time, an automation of all process steps is getting enforced. The major challenge, in addition to the difficult handling-properties of the materials and high quality demands, is the enormous variety of outline variants caused by small production quantities but many different textile cuts per part. In the first step the requirements of an automated system are exactly analyzed considering the specific material properties as well as process and product based characteristics.

Drilling fastener holes in composite is much more difficult than in aluminum or other metallic materials since individual carbon fibers fracture at irregular angles resulting in numerous microscopic voids. These voids can trap excess sealant inhibiting the intimate electrical contact between the fastener and the composite structure. As the cutting tool wears there is an increase of surface chipping and an increase in the amount of uncut fibers or resin. This condition is referred to as machining–induced micro texture. Machining–induced micro texture has been shown to be associated with the presence of arcing between the fastener and the composite structure during lightning strike tests. Lightning protection of composite structure is more complex due to the intrinsic high resistance of carbon fibers and epoxy, the multi-layer construction and the anisotropic nature of the structure.

The commercial turbofan trend of increasing bypass ratio and decreasing fan pressure ratio has seen its latest market entry in Pratt & Whitney's PurePower™ product line, which will power regional aircraft for the Bombardier and Mitsubishi corporations, starting in 2013. The high-bypass-ratio, low-fan-pressure-ratio trend, which is aimed at diminishing noise while increasing propulsive efficiency, combines with contemporary business factors including the escalating cost of testing and limited availability of simulated altitude test sites to pose formidable challenges for engine certification and performance validation. Most fundamentally, high bypass ratio and low fan pressure ratio drive increased gross-to-net thrust ratio and decreased fan temperature rise, magnifying by a factor of two or more the sensitivity of in-flight thrust and low spool efficiency to errors of measurement and assumption, i.e., physical modeling.

This paper explores the use of Poincaré plots to study signal variability of Navy P-3 aircraft generators. The method, which was inspired from nonlinear dynamics for analyzing interval sequences, is a technique used to plot each interval against the subsequent interval of the signal from different points of view. The geometry of the plots reveals salient features among new, low-usage, and high-usage generators. In addition to its simple visual interpretation, quantitative descriptors were explored to assess the degree of degradation of the overall system health state. The results suggest that accurate health state predictions can be achieved if baseline data can be collected.

The electrical and mechanical failures (such as bearing and winding failures) combine to cause premature failures of the generators, which become a flight safety issue forcing the crew to land as soon as practical. Currently, diagnostic / prognostic technologies are not implemented for aircraft generators where repairs are time consuming and its costs are high. This paper presents the development of feature extraction and diagnostic algorithms to ultimately 1) differentiate between these failure modes and normal aircraft operational modes; and 2) determine the degree of damage of a generator. Electrical signature analysis based features were developed to distinguish between healthy and degraded generators while taking into account their operating conditions. The diagnostic algorithms were developed to have a high fault / high-hour detection rate along with a low false alarm rate.

Requirements analysis for aircraft simulators is often driven by photographs and videos of the actual aircraft. An engineer may gather and organize hundreds or even thousands of source photos of various instruments and devices unique to the aircraft. Managing all of this source information and referencing it to generate software requirements can be challenging and time-consuming. This paper explores Content Based Image Retrieval (CBIR) techniques to automatically process and search those images to generate basic requirements and to facilitate reuse. An unsupervised clustering algorithm groups source images based on minimal user input. Images processed in this way can also be queried by image similarity, thereby allowing project managers to find common source material among projects. The effectiveness of these techniques is demonstrated on an example cockpit.

An aircraft environmental control system (ECS) is commonly designed for a cabin that has been divided into several thermal control zones; each zone has an air flow network that pulls cabin air over an isolated thermocouple. This single point measurement is used by the ECS to control the air temperature and hence the thermal environment for each zone. The thermal environment of a confined space subjected to asymmetric thermal loads can be more fully characterized, and subsequently better controlled, by determining its “equivalent temperature.” This paper describes methodology for measuring and controlling cabin equivalent temperature. The merits of controlling a cabin thermal zone based on its equivalent temperature are demonstrated by comparing thermal comfort, as predicted by a “virtual thermal manikin,” for both air-temperature and equivalent-temperature control strategies.

The RFID on Parts Project Team has recently completed and approved Spec 2000 Chapter 9, “RFID on Parts”. Once approved by the ATA e-Business Steering Group, this standard will allow for archiving and sharing part history information directly on RFID tags using the User Memory Bank. Using a structure similar to a File Storage System, this standard organizes tag data in a structured and indexed system so that information can be shared among all members of the supply chain. Now that high memory, passive tags are becoming available, when used in conjunction with the “RFID on Parts” standard, they make it possible to tag parts not just with an identification number, but with birth records, a full history of maintenance activities and user archives. Since end users and maintenance organizations will no longer need to rely solely on information retrieved from a centralized database, new processes and efficiencies can be realized.

At Boeing’s commercial aircraft production in Everett Washington, the organization that supplies parts to the factory floor (known internally as Company 625) is revising their methods. A new process will deliver parts in kits that correspond to the installation plans used by the mechanics. Several alternative methods are under review. The authors used simulation methods to evaluate and compare these alternatives. This study focuses on the category of parts known as standard fasteners (‘standards’). Through direct observation, interviews with experts, as well as time and motion study, the process flow of the kitting operation was mapped A simulation model was created using the simulation software ARENA to examine two scenarios: the current kitting operation in the factory cribs and the proposed centralization of kitting operation in the Company 625.

The Systems Engineering Relationship between Qualification, Environmental Stress Screening (ESS), and Reliability is often poorly understood: as a consequence resources are expended on efforts that degrade inherent hardware reliability and vitiate reliability predictions. This article expatiates on the Systems Engineering relationship between Qualification and ESS, and how their proper application enhances inherent reliability and supports credible reliability predictions. Examples of how their uninformed application degrades inherent hardware reliability and vitiates reliability predictions, and how program/equipment managers can avoid this, are presented.

The authors measured the vibratory forces acting on an airfoil model by performing a ground vibration test (GVT). The airfoil model was manufactured using rapid prototyping. In the experiments, the airfoil model's structural response was also recorded and described. This paper detailedly introduces the entire experiment process and the obtained experimental data agreed well to the actual values.

Water recovery is essential for long-duration space exploration transit and outpost missions. Primary stage wastewater recovery systems partially satisfy this need, and generate concentrated wastewater brines that are unusable without further processing. The Enhanced Brine Dewatering System (EBDS) is being developed to allow nearly complete recovery of water from Lunar Outpost wastewater brines. This paper describes the operation of the EBDS and discusses the development and testing of the major functional materials, components, and subsystems, including the wastewater brine ersatz formulations that are used in subsystem testing. The assembly progress of the EBDS full system prototype is also discussed, as well as plans for testing the prototype hardware.