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Technical Paper

Operating Procedures Associated with Noise Generated by the Supersonic Transport

1965-02-01
650214
The noise characteristics of The Boeing Company variable sweep supersonic transport are described. It is predicted that the noise levels of this airplane will be lower than those of current intercontinental subsonic jets. However, the noise generated by the supersonic transport could be substantially modified by the way the aircraft will be operated. The flexibility in operation afforded by the Boeing supersonic transport for achieving low noise levels, both airport and in the community, is reviewed. No major noise problems are anticipated because of SST operations at present airfields.
Technical Paper

Expanded Accommodation Technique with Application to Maintenance Environment

2011-04-12
2011-01-0521
This paper presents a PC based mathematical and rapid prototyping technique for anthropometric accommodation in a maintenance environment using the principle of simulation based design. The developed technique is capable of analyzing anthropometric data using multivariate (Principal component Analysis) approach to describe the body size variability of any given population. A number of body size representative cases are established which, when used properly within the constraints of the maintenance environments, will ensure the accommodation of a desired percentage of a population. This technique evaluates the percentage accommodation of a given population for the environment using the specific manikin cases as boundary conditions. In the case where any member of a maintenance crew cannot be accommodated, the technique has the capability of informing the designer of the environment why the member(s) is/are not accommodated.
Technical Paper

Ejection Seat Cushions Static Evaluation for Three Different Installation Rail Angles

2011-04-12
2011-01-0806
Jet fighter missions have been known to last extended period of time. The need for a comfortable and safe seat has become paramount considering that fact that uncomfortable seats can lead to numerous health issues. Several health effects like numbness, pressure sore, low back pain, and vein thrombosis have been associated with protracted sitting. The cushion, and of late the installation rail angle are the only components of the ejection seat system that can be modified to reduce these adverse effects. A comprehensive static comfort evaluation study for ejection seats was conducted. It provides comparison between a variety of operational and prototype cushions (baseline cushion, honeycomb and air-cushion) and three different installation rail angles (14°, 18°, and 22°). Three operational cockpit environment mockups with adjustable installation rail angle were built. Ten volunteer subjects, six females and four males, ages 19 to 35, participated in the seat comfort evaluation.
Technical Paper

A Reduced-Order Enclosure Radiation Modeling Technique for Aircraft Actuators

2010-11-02
2010-01-1741
Modern aircraft are aerodynamically designed at the edge of flight stability and therefore require high-response-rate flight control surfaces to maintain flight safety. In addition, to minimize weight and eliminate aircraft thermal cooling requirements, the actuator systems have increased power-density and utilize high-temperature components. This coupled with the wide operating temperature regimes experienced over a mission profile may result in detrimental performance of the actuator systems. Understanding the performance capabilities and power draw requirements as a function of temperature is essential in properly sizing and optimizing an aircraft platform. Under the Air Force Research Laboratory's (AFRL's) Integrated Vehicle and Energy Technology (INVENT) Program, detailed models of high performance electromechanical actuators (HPEAS) were developed and include temperature dependent effects in the electrical and mechanical actuator components.
Technical Paper

Automated Model Evaluation and Verification of Aircraft Components

2010-11-02
2010-01-1806
The trend of moving towards model-based design and analysis of new and upgraded aircraft platforms requires integrated component and subsystem models. To support integrated system trades and design studies, these models must satisfy modeling and performance guidelines regarding interfaces, implementation, verification, and validation. As part of the Air Force Research Laboratory's (AFRL) Integrated Vehicle and Energy Technology (INVENT) Program, standardized modeling and performance guidelines have been established and documented in the Modeling Requirement and Implementation Plan (MRIP). Although these guidelines address interfaces and suggested implementation approaches, system integration challenges remain with respect to computational stability and predicted performance over the entire operating region for a given component. This paper discusses standardized model evaluation tools aimed to address these challenges at a component/subsystem level prior to system integration.
Journal Article

Estimating Return on Investment for SAVI (a Model-Based Virtual Integration Process)

2011-10-18
2011-01-2576
The System Architecture Virtual Integration (SAVI) program is a collaboration of industry, government, and academic organizations within the Aerospace Vehicle System Institute (AVSI) with the goal of structuring a new integration process that relies on a “single-truth” architectural framework. The SAVI approach of “Integrate, then Build” provides a modern distributed development environment which arrests the propagation of requirements errors through the development life cycle. It does so by capturing design assumptions and shared properties of the system design in an authoritative, annotated architectural model. This reference model provides a common, analyzable framework for confirming that system requirements remain complete, consistent, and correct at all levels of system decomposition. Core concepts of SAVI include extensive use of model-based system engineering tools and use of a “single-truth” reference architectural model.
Technical Paper

Calculations of Ice Shapes on Oscillating Airfoils

2011-06-13
2011-38-0015
The desire to operate rotorcraft in icing conditions has renewed the interest in developing high-fidelity analysis methods to predict ice accumulation and the ensuing rotor performance degradation. A subset of providing solutions for rotorcraft icing problems is predicting two-dimensional ice accumulation on rotor airfoils. While much has been done to predict ice for fixed-wing airfoil sections, the rotorcraft problem has two additional challenges: first, rotor airfoils tend to experience flows in higher Mach number regimes, often creating glaze ice which is harder to predict; second, rotor airfoils oscillate in pitch to produce balance across the rotor disk. A methodology and validation test cases are presented to solve the rotor airfoil problem as an important step to solving the larger rotorcraft icing problem. The process couples Navier-Stokes CFD analysis with the ice accretion analysis code, LEWICE3D.
Technical Paper

Designing Airplane Cabin Noise Treatment Packages using Statistical Energy Analysis

2007-05-15
2007-01-2316
Statistical Energy Analysis (SEA) is a very powerful tool in its ability to guide noise control package design in automobile, airplane and architectural systems. However transmission loss modeling in an SEA frame work has more to do with modeling of sound propagation through foam and fiber noise control materials than classical SEA power flow between groups of resonant modes. The transmission loss problem is reviewed in an SEA frame work with a focus on key paths and input parameter variations on predicted noise control package performance.
Technical Paper

Robust Analysis of Active Flutter Suppression Using Multiple Control Surfaces via Second-Order Controllers

2007-09-17
2007-01-3921
The robust stability of an active flexible wing section with leading- and trailing-edge control surfaces is further investigated via the μ-method. Motivated by a more detailed servo control dynamics, the two controllers K1 and K2, which command the deflections of the trailing-edge flap and the leading-edge flap respectively, are modeled as two second-order shock absorbers in this study. The nominal and robust stability margins, modal properties, critical flutter airspeeds and frequencies are computed to predict the flutter of a nonlinear aeroelastic system and to investigate the aeroservoelastic stability in the μ-framework. The simulation results are compared with the previous study of which the controllers were modeled as the simplified (first-order) shock absorbers. The improved sensitivity to detect the control-structure coupling is observed by applying the second-order shock absorbers in the ASE model.
Technical Paper

The 747-400 Dreamlifter - Overview & Mission

2007-09-17
2007-01-3888
The development of new commercial airliners is a very risky proposition. To get it right, airframe manufacturers must balance new technologies and manufacturing methods with global participation and business considerations. The 787 is Boeing's popular new wide body aircraft incorporating state of the art composites design and manufacturing methods. But new technology alone is not enough. A new logistics system was needed to integrate global partners in order to fully benefit from new technologies. The Boeing 747-400 Dreamlifter is a special purpose 747-400 modified to transport Boeing 787 airplane components through various stages of manufacturing.
Technical Paper

Verification of Supply Chain Quality for Perishable Tools

2007-09-17
2007-01-3813
Increased emphasis on standardizing processes and controlling variability in production operations includes validating perishable tools used in daily operations. Even though dealing with reputable manufacturers, many factors including communication, custom specifications and personnel turnover can lead to the perpetuation of mistakes if errors are not discovered and corrective action implemented. However, inspection is costly and inspection costs far outweigh many item costs unless considering product defects. A beneficial balance may be obtained by employing statistical sampling techniques similar to ISO 2859 [1] to verify the quality of incoming tools.
Technical Paper

Universal Splice Machine

2007-09-17
2007-01-3782
There is an increasing demand in the aerospace industry for automated machinery that is portable, flexible and light. This paper will focus on a joint project between BROETJE-Automation and Boeing called the Universal Splice Machine (USM). The USM is a portable, flexible and lightweight automated drilling and fastening machine for longitudinal splices. The USM is the first machine of its kind that has the ability not only to drill holes without the need to deburr, (burrless drilling) but also to insert fasteners. The Multi Function End Effector (MFEE) runs on a rail system that is mounted directly on the fuselage using a vacuum cup system. Clamp up is achieved through the use of an advanced electromagnet. A control cart follows along next to the fuselage and includes an Automated Fastener Feeding System. This paper will show how this new advancement has the capabilities to fill gaps in aircraft production that automation has never reached before.
Technical Paper

Keep the User in Mind: Operational Considerations for Securing Airborne Networks

2007-09-17
2007-01-3785
Security is a serious concern for all Internet users, and all the more so if the implications of security failure can potentially affect safety of flight or the public's perception of air travel. However, when designing networked aircraft and onboard systems, technical security features are only one aspect of the implementation that must be addressed. Given the unique operational, support, and regulatory environment of commercial air transports, careful consideration must also be given to both design and operational requirements in order to develop an aircraft that can be safely operated and maintained within the constraints of the existing infrastructure and personnel available. This paper addresses the unique Operational Considerations for Securing Airborne Networks in commercial air transport aircraft.
Technical Paper

Development of Portable and Flexible Track Positioning System for Aircraft Manufacturing Processes

2007-09-17
2007-01-3781
The Boeing Company has recently developed a portable positioning system based upon its patented flexible vacuum track technology, in support of its commitment to lean manufacturing techniques. The positioning system, referred to as Mini Flex Track, was initially developed as an inexpensive drilling system that minimizes machine setup time, does not require extensive operator training due to its simple user interface, is general purpose enough to be used in varying airplane applications, and meets strict accuracy requirements for aircraft manufacturing. The system consists of a variable length vacuum track that conforms to a range of contours, a two-axis numerically-controlled positioning carriage that controls machine motion, an additional rail perpendicular to the vacuum rail that provides transverse motion, and an end effector that can perform various tasks.
Technical Paper

Microbial Characterization of Internal Active Thermal Control System (IATCS) Hardware Surfaces after Five Years of Operation in the International Space Station

2006-07-17
2006-01-2157
A flex hose assembly containing aqueous coolant from the International Space Station (ISS) Internal Active Thermal Control System (IATCS) consisting of a 2 foot section of Teflon hose and quick disconnects (QDs) and a Special Performance Checkout Unit (SPCU) heat exchanger containing separate channels of IATCS coolant and iodinated water used to cool spacesuits and Extravehicular Mobility Units (EMUs) were returned for destructive analyses on Shuttle return to flight mission STS-114. The original aqueous IATCS coolant used in Node 1, the Laboratory Module, and the Airlock consisted of water, borate (pH buffer), phosphate (corrosion control), and silver sulfate (microbiological control) at a pH of 9.5 ± 0.5.
Technical Paper

ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project - 2006 Update

2006-07-17
2006-01-2161
The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered.
Technical Paper

International Space Station (ISS) Major Constituent Analyzer (MCA) On-Orbit Performance

2006-07-17
2006-01-2092
This paper summarizes the first 5 plus years of on-orbit operation for the Major Constituent Analyzer (MCA). The MCA is an essential part of the International Space Station (ISS) Environmental Control and Life Support System (ECLSS). The MCA is a mass spectrometer instrument in the US Destiny Laboratory Module of the International Space Station. The MCA provides critical monitoring of six major atmospheric constituents (nitrogen (N2), oxygen (O2), hydrogen (H2), carbon dioxide (CO2), methane (CH4) and water vapor (H2O)) sampled continuously and automatically in all United States On-Orbit Segment (USOS) modules via the Sample Distribution System (SDS). Sample lines have been routed throughout the U.S. modules with valves to facilitate software-automated sequential sampling of the atmosphere in the various modules.
Technical Paper

International Space Station Water Usage Analysis

2006-07-17
2006-01-2094
The International Space Station (ISS) supplies and recycles water. Until the water system loop is closed with 100 percent recycling, monitoring water usage on-orbit is critical. The water supply on-orbit is monitored to stay above the skip cycle. If the rate is higher than predicted, then the water supply may become too low to support the crew. Both U.S. and Russian water experts use the water usage rate to determine the quantity of water to be re-supplied on each vehicle. The paper provides an overview of the ISS water system. It discusses the newly revised water balance. The paper describes the methodology used to calculate water usage rates. The analysis provides the water usage rates for each Expedition crew. The analysis compares these results to the consumable reports and the Russian water expert reports. The paper provides a discussion of the results of the various usage rates. It provides the most accurate methods for assessing water usage.
Technical Paper

International Space Station Nitrogen System Performance

2006-07-17
2006-01-2091
The Nitrogen System aboard the International Space Station (Station) continues to maintain Station total pressure and support several ongoing scientific and medical tasks. This paper addresses elevated leakage in the Nitrogen System, behavior during events such as nitrogen usage in other parts of the Station, and describes behavioral changes of the nitrogen Regulator/Relief Valve (regulator) since the activation of the Nitrogen System in 2001.
Technical Paper

International Space Station (ISS) Metabolic Oxygen Consumption for Expeditions 12

2006-07-17
2006-01-2090
The analysis presented in this paper focuses on the metabolic consumption of oxygen by the crew onboard the International Space Station (ISS) during Expedition 12. The Russian Elektron, which electrolyzes water to produce oxygen, operational and non-operational periods are used to assist in the calculation of metabolic oxygen consumption. Non-operational periods will be used to establish baseline crew consumption rates. The importance of this analysis is to provide more accurate trend of oxygen metabolic consumption rates for Expedition 12.
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