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Drilling fastener holes in large assemblies is traditionally accomplished through the use of large machine tools in order to obtain the accuracies required for the assembled part. Given recent advances of machine design and machine controller compensation, the accuracy of the motion platform can be corrected if the machine is repeatable. This coupled with the use of a vision system or touch probe to compensate for assembly variations, permit the use of smaller, more portable drilling systems. These smaller, more portable machine tools allow for lean manufacturing techniques to be incorporated into build processes, utilize less floor space, and in many cases are less costly than larger, permanent machine tools. This paper examines the feasibility of utilizing a small 5-axis, portable, drilling system for drilling the side panel skins on the F/A-18 E/F forward fuselage.

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.

Assembly techniques for the majority of expendable and reusable launch vehicles have not changed much over the last thirty years. Some progress has been made, specifically on new programs, however, improvements on existing expendable launch vehicle production lines can be difficult to justify; even more so for one or two reusable vehicles. This presentation will focus on techniques and systems used for manual and automated assembly of expendable and reusable launch vehicle primary structures. Today's assembly is characterized by manual operations involving fixtures and templates, and all tasks are carried out primarily with single function hand tools. Typical assembly approaches used for metallic and composite primary structures will be discussed. Potential opportunities for process improvements utilizing advanced hand tools, mechanized and/or automated equipment will be addressed.

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.

Over 200 International Space Station external high maintenance items have been designed for replacement by a dexterous robotics system in addition to space-suited astronauts. Planning for dexterous robotics maintenance increases flexibility for space station operations with a robot able to execute many tasks in place of a suited crew member, lowering the number of hours crew must spend on Extravehicular Activity (EVA). The five inboard truss segments of the station - S3, S1, S0, P1 and P3 - include 122 of these robot compatible maintenance items or On-orbit Replaceable Units (ORUs). This paper describes the impact robotic compatibility has had on the International Space Station (ISS) design, reviewing the inboard truss items as examples. Diverse challenges exist to verify each genre of ORU meets the dexterous robotics requirements.

During a recent International Space Station (ISS) flight (Flight 2A.1), an improper ventilation event might have occurred and resulted in stuffy air, as reported by the crew. Even though no air samples were analyzed, the accumulation of metabolic CO2 in the ISS was suspected as the cause of the crew sickness. With no possibility of conducting an on-orbit test of this kind, it was decided to utilize Computational Fluid Dynamics (CFD) analysis to investigate this problem. Based on the Flight 2A.1 and 2A.2a configurations, a CFD model of the air distribution system was built to characterize airflow between the ISS elements. This model consists of Inter-module Ventilation (IMV) covering the Functional Cargo Block (FGB), two Pressurized Mating Adapters (PMA-1 and PMA-2), the Node-1, and portions of the Orbiter volume.

The United States Propulsion Module (USPM) is a pressurized element and provides reboost, propulsive attitude control, control moment gyro (CMG) desaturation, and collision avoidance functions for the International Space Station (ISS). The USPM will dock with Node 2 at the pressurized mating adapter-2 (PMA-2). After docking with PMA-2, the USPM will provide mechanical and structural interfaces to the Space Shuttle, along with facilities for crew transfer and receiving resupply oxygen, nitrogen, water, helium, and propellants from the Space Shuttle. It is essential that the USPM maintain a safe and functional life support system during crew member passage and maintenance activities. It is complex and costly to design an operational system to satisfy all ISS requirements. This paper details an innovative USPM environmental control and life support system (ECLSS) design that satisfies all ISS requirements at a reduced cost.

The process of developing a Payload Attach System (PAS) which will support a wide range of experimental and commercial payloads on the International Space Station (ISS) has experienced an interesting evolution during its design, development, test and evaluation (DDT&E) phase. This evolution has been caused in large measure by requirements intended to insure compatibility of the PAS with the extravehicular activity (EVA) crewmember during nominal and contingency operations in and around the PAS sites. As the design of the ISS transitioned from its Freedom predecessor, the effort to keep costs down by preserving as much of the original Freedom design as possible led to design decisions that challenged engineering thinking.

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. This paper reports on the results of Open Hatch ECLSS/ TCS Tests for International Space Station’s Lab Module. The hardware tested is referred to as proto-flight hardware. Upon satisfactorily passing these Open Hatch and later Closed Hatch, imposed ground based, proto-flight tests, the proto-flight hardware will become flight hardware. The Lab Module is scheduled for launch during late 1999. The particular ECLSS/TCS equipment discussed here are the Temperature Humidity and Control (THC) equipment and Intermodule Ventilation (IMV) equipment.

At The Boeing Company, the advent of a Determinant Assembly (DA) program and the subsequent production of accurate fuselage subpanels created a need to be able to position subpanels accurately and repeatably during fuselage assembly. The tool engineering organization of The Boeing Company and Advanced Integration Technology, Inc. (AIT) as the prime contractor, are developing and installing automated positioning and alignment systems throughout major 747 fuselage assembly areas which enable DA techniques. The benefits of this assembly approach and this automated precision tooling are flexibility, assembly accuracy, ease of assembly and associated speed, reduced downtime for tool maintenance, and improved shop-floor ergonomics.

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 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.

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.

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 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.

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 considerable amount of integrated Environmental Control and Life Support System (ECLSS) analysis has been performed and documented for the proposed habitable Space Station. Earlier analytic activities have resulted in highly refined models simulating Temperature and Humidity Control (THC) and Atmosphere Revitalization (AR) hardware. As the mechanisms by which these items affect the Space Station environment have become better understood (along with the effects due to operation of various Man Systems utilities), the next stage of the integrated analysis task has been accomplished; i.e., the simulation of the Atmosphere Control and Supply (ACS) subsystem. The focus of the present paper is upon the ACS function in the overall life support system. Modeling of the ACS is unique among the life support disciplines in that it requires accurate representation of all other ECLSS subsystems that interact with the cabin atmosphere (which has now been achieved) in order to be realistic.

This paper reviews the recent G189A computer program developments in the area of humidity control for the U.S. Lab Module in the Space Station. The humidity control function is provided as an indirect or passive function by the Common Cabin Air Assemblies (CCAA) in pressurized elements or modules in the Space Station. The CCAAs provide active cabin temperature control through implementation of a digital/electromechanical control system (i.e., a proportional/integral (PI) control system). A selected cabin temperature can be achieved by this control system as long as the sensible and latent heat loads are within specified limits. In this paper three pertinent analytical cases directed to determining minimum or maximum dew point temperatures are discussed. In these cases the basic sensible heat loads are set at constant values.

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.