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Technical Paper

Variable Geometry in a Supersonic Transport Aircraft

The variable-geometry features of the United States supersonic transport are described. Particular attention is given to the hardware development of those variable-geometry features unique to the supersonic transport. The design, development, and current status of a direct lift control sys tern, the supersonic internal-external compression inlet, and the full-scale wing pivot are described.
Technical Paper

The United States SST and Air Quality

The feasibility of commercial supersonic flight has been questioned on the basis of air pollution and an alleged potential for altering the world's climate and weather. A study conducted by Boeing reveals no basis for any of these claims. However, in some cases more data are required to show there is no effect.
Technical Paper

The Pilot and the Flight Management System

This paper addresses the question of whether automation is being used in the proper applications in aircraft in order to maximize aircraft capabilities and make the most of human performance capacity. It is believed that the aircraft designers, while employing automation, have given due regard to the pilot's role as operator and manager of the aircraft. There does, however, seem to be valid concern for the human element in certain aspects of the air traffic control system.
Technical Paper

Test Results of the Effects of Air Ionization on Cigarette Smoke Particulate Levels Within a Commercial Airplane

Passengers and flight attendants often notice a haze of smoke under the overhead stowage bins in aircraft cabins when cigarette smoking is allowed. As normally operated, the ventilation system in Boeing 737/757 aircraft does not rapidly remove this smoke haze. Air ionization systems from three vendors were tested in a 10 foot long Boeing 737/757 cabin test section with a cruise condition ventilation rate and two cigarette smoking rates to assess their effectiveness in removing smoke haze from the local breathing areas of passengers and flight attendants. Smoke particulate densities were monitored at five breathing areas and at an exit grill in the test section. All of the ionization systems significantly increased the rate of smoke removal after smoking had stopped, increasing the removal rate by about 25%. None of the systems showed a statistically significant reduction of smoke levels at the individual monitoring points while cigarettes were being smoked.
Technical Paper

Specification Reform of Avionics Thermal Design Criteria – An F-15 Case Study

Traditional thermal design criteria for avionics equipment are reviewed. Several studies have recently been conducted on the F-15 to assess accuracy of these design criteria. An overview of the study approach and results are presented. Specific topics investigated include: emergency cooling air provisions, cold start-up, hot start-up, normal and transient bay temperatures, and altitude design. The results indicate that many existing design criteria are overly conservative. The study findings suggest that reform of the existing thermal specification process is needed. Many of these reforms are applicable to the general aerospace industry and may result in significant acquisition cost savings as a result of the trend toward usage of commercial electronic parts. The reforms suggested include a new performance based thermal specification approach that increases emphasis on aircraft usage and frequency of occurrence. New transient design criteria are also recommended.
Technical Paper

Space Station THC/IMV Development Test/Analysis Correlations and Flight Predictions

The International Space Station (ISS) Temperature and Humidity Control/Intermodule Ventilation (THC/IMV) system for the U.S. Lab provides required cooling air for the U.S. Lab and also provides “parasitic” cooling air for Node 1 and its attached elements. This scheme provides cooled air from the Lab THC directly to Node 1 and also to elements attached to Node 1, at different stages of Space Station assembly. A development test of the U.S. Lab and Node 1/attached elements' integrated THC/IMV ducting system was performed in the summer of 1995. This test included the U.S. Lab's development level Common Cabin Air Assembly (CCAA), which removes sensible and latent heat from the circulated and ducted cabin air. A referenced 1996 ICES Paper contains the initial correlation results. An analytical model has been developed, which has been used to predict flow and pressure drop performance of the system for several potential and actual changes from the Development Test configuration.
Technical Paper

Radar Detection of Turbulence in the Upper Troposphere

Encounters of jet aircraft with high altitude turbulence prompted the investigation of various techniques to probe and locate turbulence in areas lacking particles (rain drops, hailstones). A promising technique is to measure the radio refractive eddies and gradients by radar backscatter. Radio refractive index eddies can, in principle, be found where an atmosphere characterized by a nonadiabatic lapse rate of refractive index is stirred up by turbulence. A sequence of VHF backscatter experiments which will hopefully lead up to an airborne CAT detector are presented in this paper.
Technical Paper

Process Automation Through-Reality Graphics, Kitting, and Automated Panel Protection

This paper addresses process improvements through reality graphics (RG) aided by automated panel protection (APP) and tool kitting pertaining to automated wing riveting and fastening. This system provides an integrated display of numerical controlled media, automatic tool identification, and image files, combined with automated panel protection. Reality graphics (image files) within the NC program allow the machine operator to access portions of the NC program while attaching a support graphic. This would include safety hazards, unique panel differences, program start, and tool change information. Automated panel protection (APP) analyze process key characteristics, and perishable tool kits, and it monitors the installation of fasteners using multiple cameras mounted in strategic positions, taking real-time images. The APP detects incorrect tooling and possible panel damage, with little or no impact to the operational cycle time of the automated fastening equipment.
Technical Paper

Nozzle Development for the Upper Surface - Blown Jet Flap on the YC-14 Airplane

A discussion of wing-nozzle configuration development for the application of upper surface blowing to a STOL airplane is presented. The technical challenge is to achieve an integrated system which provides the desired performance for the low speed design conditions and also results in efficient operation during cruise. The resulting configuration is a complete integration of the propulsion system and airplane aerodynamics to achieve efficient operation at all regimes. This paper examines the major design parameters to be considered, describes a number of the configurations tested, and presents static and wind tunnel test results for these configurations. Concluding remarks are made relative to USB nozzle development.
Technical Paper

Non-Linear Aeroelastic Predictions for Transport Aircraft

A loosely coupled method for aeroelastic predictions of aircraft configurations is shown. This method couples an advanced structural analysis method with a CFD aerodynamics code in a modular fashion. This method can use almost any CFD code, so a validation of several such codes is shown to establish regions of validity for each code. Results from potential codes, an Euler code, and a Navier-Stokes code are shown in comparison with experiment. Viscous effects are included in most cases through a coupled boundary-layer solver or a turbulence model as appropriate.
Technical Paper

Noise Implications for VTOL Development

Noise from the aircraft may prevent the establishment of VTOL ports near population centers-the locations which can provide a significant contribution to mass transportation. To determine how annoying these aircraft may be, a total community annoyance measure (TCAM) has been developed. The TCAM can indicate flight trajectories which minimize the annoyance of the aircraft and the type of aircraft which are acoustically acceptable for operations from a V/STOL port. Low disc loading rotors seem best for operation near terminals while low tip speed propellers are best for cruise.
Technical Paper

Modeling and Simulation of Complex Hydraulic Valves Using EASY5 Software

Many mechanical systems employing fluid power use one or more valves to control fluid flow. Often these valves can be quite complex, with many inlets and exits, reversing flow, flow and pressure control, and other unique features. It is desirable to model these valves and the associated fluid and control logic circuits with software during the design phase, and explore the effect of design changes on system performance using simulation and other analyses without having to build and modify expensive prototypes. A number of commercially available software packages offer various methods for “graphically modeling” dynamic systems, and some, offer the user pre-defined libraries of hydraulic components that greatly speed the modeling process. However, the variations on valve design are unlimited, and it is often necessary to model a hydraulic valve that has not been previously defined. This paper describes an approach allowing essentially any valve configuration to be modeled.
Technical Paper

Managing the Technical Development of the 727

Studies in a jet passenger airliner to service shorter routes than those of the Boeing 707 evolved the concept of a rear mounted three engine jet, the 727. The development program had many facets, including extensive use of mockups, customer influence on design through liaison, cost control, and a considerable amount of work on the design of the tail and location and number of engines on the craft.
Technical Paper

Integrated Metrology & Robotics Systems for Agile Automation

Aircraft manufacturing in the 21st century sees a future much different to that seen one and two decades before. Manufacturers of both military and commercial aircraft are challenged to become Lean, Agile and Flexible. As progress is slowly made toward introducing advanced assembly systems into production, the overall cost of automation is now more closely scrutinized. After spending tens of millions of dollars on large automated systems with deep foundations, many manufacturers find themselves locked into high cost manufacturing systems that have specific, inflexible configurations. This kind of scenario has caused a shift in the attitude of airframe assemblers, to go back to basics. Lean manufacturing is seen as a way to build aircraft with very low investment in equipment and tools. Today's advanced systems developers do understand the need for more affordable assembly systems.
Technical Paper

Inlet Hot Gas Ingestion (HGI) and Its Control in V/STOL Aircraft

A successful methodology was developed at Boeing Company to investigate hot-gas ingestion in vertical take-off and landing aircraft. It involves sub-scale model testing using specialized test facilities and test techniques. The baseline characteristics of hot-gas ingestion (HGI) and the performance of various HGI reduction techniques were qualitatively evaluated in the Boeing Hover Research Facility. Potential HGI reduction devices were then further tested at scaled pressures and temperatures in HGI facilities at NASA Lewis, Rolls Royce and British Aerospace. One of the successful HGI reduction devices was flight tested. This paper describes the application of Boeing HGI reduction methodology to three specific aircraft configurations.
Technical Paper

F/A-18 E/F Outer Wing Lean Production System

The Boeing F/A-18 E/F Program Wing Team, Lean Organization and Phantom Works have partnered to develop a “state of the art” lean production system for the Outer Wing that represents an evolutionary change in aircraft design and assembly methodology. This project is focused on improving quality, cycle and cost performance through the implementation of lean principles, technology integration and process improvements. This paper will discuss the approach taken to reach the end state objectives and the technologies and processes being developed to support it. Items to be discussed include lean principles and practices, new tooling concepts, improved part assembly techniques, advanced drilling systems, process flow enhancements and part handling/part delivery systems.
Technical Paper

Evolution to Lean Manufacturing A Case Study of Boeing of Spokane

The evolution of a manufacturing organization toward “Lean” manufacturing does not necessarily come cheaply or quickly. It is the experience at Boeing that technology and different visions can dramatically impact the evolutionary process-consuming great amounts of time and resources. The Boeing of Spokane case study, where aircraft floor panels are manufactured1, is but one of several case studies that suggests moving to “Lean” manufacturing is usually done in large steps, not small ones. These initial steps can be costly unless the systems (equipment and workforce) are flexible. Workforce flexibility is dependent on the attitude in the workforce as both touch and support labor move from their comfort zone to try new approaches and job descriptions. The workforce must be properly motivated to make the change. The equipment must also be flexible in adapting to new line layouts, product mixes, and process change or large cost penalties will be incurred.
Technical Paper

Engine Maintenance Cost Reduction Through Improved Component Design and Development

High maintenance costs of the three 40,000 lb. thrust class aircraft engines manufactured by Pratt and Whitney, General Electric, and Rolls-Royce are discussed. Primary emphasis is on existing engine problems which contribute to high shop visit rate. Maintenance cost in terms of monetary value is not discussed. Concludes that increased emphasis on total life cycle durability is necessary by the engine manufacturers. Recommends higher level of priority be given durability in design and analysis, pre-production proof-of-design testing, and engine program management.
Technical Paper

Engine Cycle Considerations for Future Transport Aircraft

Recent noise technology advancements have provided an increased understanding of true engine noise “floor” levels. This has led to changes in necessary engine cycle requirements for low-noise commercial airplanes. Updated prediction techniques for the core and jet noise sources are described, and lining technology improvements are reviewed. The need for further work in the core noise area is emphasized. The impact of these noise technology revisions on the best engine cycle for obtaining low noise is presented. It is concluded that engines with lower bypass ratios than previously anticipated may be acceptable.
Technical Paper

Economic and Safety Aspects of Short Haul V/STOL Aircraft on High Density Routes

Intercity automobile travel has a direct effect on the volume of short haul air travel. Automobile transportation is quicker and more economical as compared with the long ground waiting time and higher rates of short air trips. A multistop system, using the V/STOL aircraft, between cities may save passengers time by closer departure points, and increased passenger miles may reduce rates. Advantages of speed and less cost enjoyed by automobile travelers may well be offset by these developments. A mere 15% transfer of short haul trips to aircraft could result in as much as 106% increase in air revenue passenger miles.