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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.

The repairing of commercial aircraft is a complex task. Service engineers at Boeing's Commercial Aviation Services group specialize in providing crucial repair information and technical support for its many customers. This paper details factors that influence Boeing's response time to service requests and how to improve it. Information pertaining to over 5000 service requests from 2008 and 2009 was collected. From analysis of this data set, important findings were discovered. One major finding is that between 6 and 8 percent of service requests are late because time/date stamps used in reports were created in a different time zone.

This paper is an explanation of some of the Flight Test Safety (FTS) methods used to reduce the risk associated with military rotorcraft development. Two flight test programs are addressed, the V-22 Osprey tiltrotor and the RAH-66 Comanche helicopter. A short history of the development of each program is provided as background information. Some of the challenges and strengths of joint ventures are also identified and discussed. Four critical elements of an FTS program are identified: 1) Organizational Risk Management (ORM), 2) issue/anomaly resolution, 3) incident recording and corrective action documentation and 4) interface between FTS and other organizations. Methods used in the two programs to address these elements are reviewed and can be applied to other flight test programs.

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.

Distortion and buckling of aluminum aerospace components can be caused by machining-induced residual stress or by residual stress induced earlier in material processing. This stress is characterized through layer removal experiments and measurements of surface location. This stress is correlated to two machining process parameters, which can be changed, in order to control distortion and buckling of machined metallic components. Experiments are presented which compare distortion of thin machined parts to distortion of chemically milled parts in order to uncouple material bulk stress from machining-induced stress.

The patented (US 7,277,811 B1) Position Bar provides precise measurement, machining and drilling data for large Engineering and Tooling structure. The Position Bar also supports end item verification seamlessly in the same machining control code. Position Bar measurements are fast, accurate, and repeatable. The true centerline of the machine tool's spindle bearings are being measured to within .002 in a 20 foot cubic volume (20×20×20). True “I”, “J”, & “K” machine tool spindle positions are also precisely measured. Any Gantry or Post Mill Tool can be converted to a Coordinate Measurement Machine (CMM) with this laser tracker controlled Position Bar. Determinant Assembly (D.A.) holes, for fuselage and wing structures are drilled and then measured to within .006 in X, Y, & Z, over a 40 foot distance. Average laser tracker measurement time, per hole, is 2 seconds.

More electric aircraft (MEA) architectures have increased in complexity leading to a demand for evaluating the dynamic stability of their advanced electrical power systems (EPS). The system interactions found therein are amplified due to the increasingly integrated subsystems and on-demand power requirements of the EPS. Specifically, dynamic electrical loads with high peak-to-average power ratings as well as regenerative power capabilities have created a major challenge in design, control, and integration of the EPS and its components. Therefore, there exists a need to develop a theoretical framework that is feasible and useful for the specification and analysis of the stability of complex, multi-source, multi-load, reconfigurable EPS applicable to modern architectures. This paper will review linear and nonlinear system stability analysis approaches applicable to a scalable representative EPS architecture with a focus on system stability evaluation during large-displacement events.

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.

The temperature and humidity of the air within the habitable areas of the International Space Station are controlled by a set of hardware and software collectively referred to as the Temperature and Humidity Control (THC) subassembly. This subassembly 1) controls the temperature of the cabin air based on a crew selected temperature, 2) maintains humidity within defined limits, and 3) generates a ventilation air flow which circulates through the cabin. This paper provides descriptions of the components of the THC subassembly, their performance ranges, and the control approach of the hardware. In addition, the solutions of the design challenges of maintaining a maximum case radiated noise level of NC 45, controlling the cabin air temperature to within ±2°F of a setpoint temperature, and providing a means of controlling microbial growth on the heat exchanger surfaces are described.

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.

The Carbon Dioxide Removal Assembly (CDRA) is a part of the International Space Station (ISS) Environmental Control and Life Support (ECLS) system. The CDRA provides carbon dioxide (CO2) removal from the ISS on-orbit modules. Currently, the CDRA is the secondary removal system on the ISS, with the primary system being the Russian Vozdukh. Within the CDRA are two Desiccant/Adsorbent Beds (DAB), which perform the carbon dioxide removal function. The DAB adsorbent containment approach required improvements with respect to adsorbent containment. These improvements were implemented through a redesign program and have been implemented on units on the ground and returning from orbit. This paper presents a DAB design modification implementation description, a hardware performance comparison between the unmodified and modified DAB configurations, and a description of the modified DAB hardware implementation into the on-orbit CDRA.

In situations of unanticipated maneuvers of an aircraft, information must be immediately received by the aircrew for correcting the aircraft flight path to a safe trajectory for continued flight and landing. These maneuvers may be due to failures in the control system, wind gust upsets, or other off-nominal conditions. Also critical are situations of control maneuvers that exceed the normal flight envelope of the aircraft, and providing information to the pilot and control system that will result in safe return to controllable flight. The Intelligent Damage Adaptive Control System (IDACS) operates during flight to detect dangerous conditions of the aircraft and to provide the crew with assistance to restore and to maintain safe control. This system is being developed by Boeing for NASA.

International Space Station (ISS) Payload Engineering Integration (PEI) organization adopted the advanced computation and simulation technology to develop integrated electrical system models based on the test data of various sub-units. This system model was used end-to-end to mitigate system risk for the integrated Space Shuttle Pre-launch and Landing configurations. The Space Shuttle carries the Multi-Purpose Logistics Module (MPLM), a pressurize transportation carrier, and the Laboratory Freezer for ISS, a freezer rack for storage and transport of science experiments from/to the ISS, is carried inside the MPLM. An end-to-end electrical system model for Space Shuttle Pre-Launch and Landing configurations, including the MPLM and Freezer, provided vital information for integrated electrical testing and to assess Mission success. The Pre-Launch and Landing configurations have different power supplies and cables to provide the power for the MPLM and the Freezer.

A new high speed forming process for fatigue rated index head rivets used in wing panel assembly using ball-screw based servo squeeze actuation has been developed. The new process is achieved using a combination of force and position control and is capable of forming to 40,000 lbs at rates of up to 200,000 lbs/second whilst holding the part location to within +/− 10 thousandths of an inch. Multi-axis riveting machines often have positioning axes that are also used for fastener upset. It is often the case that while a CNC is used for positioning control, another secondary controller is used to perform the fastener upset. In the new process, it has been possible to combine the control of the upset process with the machine CNC, thus eliminating any separate controllers. The fastener upset force profile is controlled throughout the forming of the rivet by using a closed loop force control system that has a load cell mounted directly behind the stringer side forming tool.

A multi-element fixed control volume integrated air interchange system performance computer model has been developed and upgraded for the evaluation/assessment of atmospheric characteristics inside the crew compartments of the mated Orbiter and International Space Station (ISS). In order to ensure a safe, comfortable, and habitable environment for all the astronauts during the Orbiter/ISS docked period, this model was utilized to conduct the analysis for supporting the early ISS assembly missions. Two ISS assembly missions #2A and #4A were selected and analyzed.

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.

A fundamental part of airplane manufacturing involves hand drilling of holes for fasteners (bolts and rivets). The integrity of a fastener depends on the quality of its hole, which must be properly positioned, have a circular diameter of correct dimension, and be free of surface flaws and contaminants. A common method of drilling training is for a student to drill holes under the supervision of an instructor who inspects or measures the holes and makes suggestions for improving technique. This training method has proven to be effective, but it is time-consuming and requires considerable personal attention. We have devised instrumentation to monitor critical parameters (drill orientation and forces) so that a student can receive instantaneous visual feedback. This real-time feedback provides the student a better understanding of the drilling process and allows him or her to quickly make improvements.

There have been 17 fuel tank ignition events on commercial airplanes since 1959 that have resulted in 542 fatalities and 11 airplane losses. On the military side there have been 12 airplane losses on military version of the B-707 and the B-52 airplanes. The Most notable accident was the TWA 800 in July 1996 on the Boeing 747 which caused loss of 230 lives. This paper looks at the potential root causes of fuel tank explosions and the corrective actions that industry can undertake to minimize the hazard of fuel tank explosions. Fuel tank flammability and ignition sources are considered. The areas looked at are design, installation, and maintenance. Compliance to Federal Airworthiness Regulation are reviewed.

To serve the requirements of the operational environment of modern jet aircraft, the flight crew training program should be kept as simple as possible and be consistent with the total information system for aircraft operation of which it is a part. Systematic tools are described which assist the course developer in optimizing the implementation of Specific Behavioral Objectives, allocating learning elements to the most cost effective learning environment, and organizing those learning elements associated with the classroom environment. Included is a discussion on the management systems applied, the development of a Learning Task Analysis, and a systems approach to course organization.

This paper covers issues related to the installation, testing, and production implementation of a large-scale automated wing drilling/fastener installation system. Emphasis is placed on describing the production process, foundation requirements, axes alignment, calibration, testing and implementation. Description will include key hardware features such as the multi-function end effector and spindle end effector. The objective is to convey the complexity of implementing this system as well as reviewing the lessons learned from this experience.