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The International Space Station (ISS) Temperature and Humidity Control (THC) system has been designed with the intent of supplying the air cooling needs of various elements from the U.S. Lab heat exchanger assembly. Elements without independent air cooling capability are known as “parasitic” elements; these are Node 1, the Cupola, and the Mini Pressurized Logistics Module (MPLM). Analysis results are presented which show expected temperatures in the MPLM, and Node 1, as various heat loads are present in the respective elements. Analyses within this paper are coordinated with the results obtained from the Development Test of the complex USL/Node 1 integrated ducting system. This test was conducted in the summer of 1995, at the McDonnell Douglas test facility in Huntington Beach, California.

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.

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.

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.

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.

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.

Understanding the friction behavior of brake lining materials is fundamental to the ability to predict brake system performance. Of particular interest to the aviation community, where carbon/carbon composite heatsinks are commonly used, is the aircraft response at deceleration onset. There are two performance measures defining brake system performance at braking onset: deceleration onset rate and system response time. The latter is strictly a function of the brake system hydraulics and is not affected by brake lining friction. The former performance measure is a function of both system hydraulics and brake lining friction. Previously to the work herein, carbon heatsink friction was thought to be unpredictable at braking onset. That being the case, a predictive capability for deceleration onset rate was not previously undertaken. This meant that assessment of this performance measure waited until aircraft taxi tests were performed.

This paper presents the basic test data obtained from tests of a cabin air distribution system in a simulated Space Station U.S. Lab-A module. The cabin air distribution system controls the flow of air in the open space of a Space Station module. In order to meet crew comfort criteria the local velocities for this cabin air are required to be distributed within a specified range with upper and lower limits. Achieving this desired velocity distribution is dependent upon the: (1.) design of the cabin air supply equipment and cabin air return equipment, (2.) total flowrate of air supplied to and subsequently returned from the cabin, and (3.) interactive effects of any other additional air flow streams which enter and exit the cabin. The basic Space Station design for the cabin air supply and air return equipment was used in this test program. Only directional adjustments to vanes in supply air diffusers were made during the test.

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.

Flight testing of aircraft under natural icing conditions can be extremely tedious, time consuming, costly, and somewhat risky. However, such testing has been required to demonstrate the effectiveness of anti-icing systems and to certify new aircraft models. To reduce the need for extensive flight testing, Boeing has built a new icing tunnel that has the capability for developing ice shapes and evaluating anti-icing features on full scale sections of critical parts of the aircraft. The icing tunnel was made by modifying an existing 5 ft by 8 ft Boeing Wind Tunnel to add icing capabilities. This paper describes the design specifications, the tunnel capabilities, and the major equipment systems and presents the results of the tunnel calibration relative to the specified requirements.

The Space Station program was faced with a unique design environment-to design a common systems and payload support structure that could accommodate changeout for repair or technology growth over a 30-year lifetime. The vibration environment and weight allocation for rack structure necessitated a lightweight, yet stiff structure. The design answer was a modular rack structure using graphite/epoxy composites and selected aluminum components that could support a wide variety of systems, payload and stowage functions. A modular set of mounting locations allow the installation of a wide variety of secondary structures without permanent modifications to the rack. Aircraft-style seat track rails on the front edges of the rack permit attachment of handrails, foot restraints and accessories such as lights, fans, clipboards or computers to the rack face.

A new process has been developed to cold work fastener holes on commercial aircraft flap tracks fabricated of 4340M steel. The process consists of pressing a high strength solid mandrel through a previously prepared hole in a defined manner. This process exhibits high tool life, low overall cost and eliminates the necessity for a final ream operation.

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.

The new 757/767 transports will be the first Boeing Commercial aircraft to commit advanced graphite composite material to initial production. Composite materials, mainly fiberglass in an epoxy matrix, have been used in Boeing military and commercial aircraft in ever increasing amounts for the past twenty (plus) years. Recently, the state-of-the-art of Advanced Composites (graphite and graphite/Kevlar hybrids in an epoxy matrix) progressed to the level that it could be committed to full-scale production. This production commitment resulted in a multi-year, multi-million dollar development program. This was to assure technical and production readiness, and product reliability to meet the stringent performance and safety standards of modern commercial transport.

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.

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.

Gas turbines have demonstrated their practicability in trucks, particularly those needing high horsepower and light weight combined with agility and reliability. These are the primary requirements of emergency vehicles such as fire fighting pumpers and crash trucks. Several installations powered by Boeing gas turbines are described, and comparisons to reciprocating engines are made. For vehicles of high power/weight ratio, the built-in torque converter feature of two-shaft gas turbines provides the automatic transmission feature that is needed for high density traffic operation or for hilly terrain. Trends in gas turbine design are briefly mentioned along with other system requirements for emergency vehicles.

The joint development of an augmentor wing jet STOL research aircraft by NASA and the Canadian Government Department of Industry, Trade, and Commerce has progressed to the point that the design of the modifications to the de Havilland C-8A Buffalo are complete and the engines are being tested. The predicted performance shows that the airplane will be able to take off and land in less than 1500 ft. Simulation studies indicate that the handling qualities of the airplane, with stability augmentation, will be acceptable for STOL research missions.

Since the advent of the turbojet engine, there has been much research by aircraft and engine manufacturers into the source of aircraft noise and its reduction. A review of this research is presented delineating the transition from turbojet engines to turbofan engines to the high by-pass ratio engines being introduced today, and the progress that has been made. Application of the current state-of-the-art to existing airplanes through engine replacement, nacelle retrofit, and flight procedures are also discussed.

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.