Search Results

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.

The utility of airplane flow-field measurements for wind-tunnel testing is reviewed. The methods and equipment developed at Boeing for these measurements are also described. The details of the latest system are presented along with typical results from recent wind-tunnel tests. Using the latest system, flow-field surveys of airplane configurations in industrial low-speed and transonic wind tunnels provide spatial distributions of lift and drag (profile and induced) with good repeatability. In addition, the probe speed and survey region is optimized so that typical full-wake surveys take 20-30 minutes to complete. Final data, displayed as total pressure, velocity vectors, vorticity contours, and distributions of lift and drag (profile and induced) are available approximately 10 minutes after survey completion.

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.

This paper presents a detailed overview of the advantages and benefits of using 2-D barcodes, called Data Matrix codes, on Wing Fastening System (WFS) Tooling. This project was conducted on, but not limited to, the 777 Wing Fastening System (GEMCOR) tooling including the drills, fingers, and button dies. This paper will show how using Data Matrix codes to identify tooling will: Eliminate excessive downtime due to the operator using the incorrect tooling for a given tool setup. Reduce the cost associated with panel rework due to the use of incorrect tooling. Reduce the cost associated with excessive tool inventory or last minute ordering to keep up with production needs. Track tool life information for each specific tool. Provide operators with an easy to use tool setup reference document. And provide the factory with the ability to trace panel damage or defects back to the specific machine and exact tooling used.

The Boeing Aero Grid and Paneling System (AGPS) is a programming language with built-in geometry features. Accessible through either a graphical user interface (GUI) or through a command line, AGPS can be used by operators with different levels of experience. Distributed with AGPS are approximately 300,000 lines of macros, or command files, which automate many engineering design and analysis tasks. Most command files were developed to produce inputs to engineering analysis codes such as A502 [1] and TRANAIR [2]. In many cases, command files have been grouped together in AGPS “packages,” which offer users simple menu pick and dialog options to automate entire engineering processes.

There are a large number of space structures, orbital replacement units (ORUs) and other components that must be transported to orbit on a regular basis for the assembly and maintenance of the International Space Station (ISS). Some of this hardware will be ferried on the Spacelab Logistics Pallet (SLP), which has a long and reliable history of space flight successes. The carrier is well used, well qualified, and very adaptable for repeated use in accommodating cargoes of various sizes and shapes. This paper presents an overview of past, present and future hardware design solutions that accommodate EVA operations on the SLP. It further demonstrates how analysis techniques and design considerations have influenced the hardware development, EVA operations, and compliance with human engineering requirements for the SLP.

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.

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.

A review of the current extended-range twin-engine operations (ETOPS) and the modifications to the standards and processes that led to its successful operational record has contributed to the feasibility of developing an airplane and preparing an operator for ETOPS at entry into service. The airplane and engine manufacturers and component suppliers have continued to expand on these modified standards and processes in their design, build, test and support programs to meet regulatory authority ETOPS requirements and to facilitate the development of regulatory authority criteria for substantiating ETOPS capability prior to entry into service. Airlines, in conjunction with the manufacturers, have also developed improved processes that meet regulatory authority requirements for preparing an operator to integrate a new airplane into its existing ETOPS programs at entry into service.

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.

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.

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.

In this lecture, a review of Boeing commercial transport models is presented in chronological order from the B-1 flying boat of 1919 to the 747. The problems of air transport systems including convenience, reliability, safety, comfort, performance, and financial and environmental costs are discussed. The probability of more severe future problems is considered, and suggestions are offered as to technology and system improvements which may need to be pursued if civil air transport systems are to continue to provide fast, convenient transportation with a high level of public acceptance.

An overview of composite structure required for manned orbiting space stations is presented. Following a brief introduction of typical configurations and major subsystems, the major structural areas requiring composite structure and their particular functions and requirements are discussed. A summary weight breakdown is presented to assess the dependence of launch weight on these areas. To illustrate, the primary wall composite structure is presented in detail. The design interplay of boost, pressure, meteoroid, radiation, and thermal control requirements are presented. Resultant composite structure for each remaining major structural area is presented in summary form with a brief description of typical design compromises required.

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.

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.

The traditional method of determining the net thrust of an engine in cruise is explained. It is shown to result in a satisfactory net thrust uncertainty for jet and low bypass ratio engines but to be unsuitable for high bypass ratio engines. A redefinition of net thrust results in a new thrust determination method, called continuity method, which yields acceptable levels of net thrust uncertainty. The new method no longer requires supporting tests in a simulated altitude facility. The question is raised whether in future programs the demonstration of guaranteed cruise performance of an engine should not be carried out in flight tests rather than in an altitude test facility.

The purpose of this paper is to provide a general process for human model analysis in the digital mock-up environment. It is also intended to provide some basic guidelines for the use and application of human models. This document is intended for anyone who will be performing human model analyses. It is assumed that the person performing the analysis has at least a minimal level of training in the use of the software involved. Note that this document is limited to anthropometric and ergonomic modeling.

Two spindles are discussed in this paper. The first spindle was installed on nine C-frame riveters on the 737/757 wing line at the Boeing Renton facility. Due to discontinuing the use of Freon coolant and cutting fluid, the C-frame riveters had difficulty shaving 2034 ice box rivets with the existing 6000 RPM hydraulic spindles. The solution was to install electric 30,000 RPM shave spindles inside the existing 76.2 mm (3 in.) diameter hydraulic cylinder envelope. The new spindle is capable of 4 Nm (35 in. lbs.) of torque at full speed and 110 kgf (250 lbs.) of thrust. Another design of interest is the Electroimpact Model 09 spindle which is used for 20,000 RPM drilling and shaving on wing riveting systems. The Model 09 spindle is a complete servo-servo drilling system all mounted on a common baseplate. The entire spindle and feed assembly is only 6.5″ wide.

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.