SAWE Technical Papers

@inproceedings{1891,

title = {1891. Development of a Mass Properties Database Plotter and Mass Distribution Program},

author = {J H Nakai},

url = {https://www.sawe.org/product/paper-1891},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {78},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {This paper describes the concept, development process, and software architecture of two mass properties analysis computer programs. The first is MPPLOT (Mass Properties PLOTter), is used to verify the accuracy of mass properties models through the use of interactive, three-dimensional, color graphics. The second is MASDIS (MASs DIStribution), which is used to distribute masses from a mass properties data base model to a NASTRAN finite element model. The efficiency of the mass properties database verification process is greatly enhanced through the use of MPPLOT. MASDIS provides a highly efficient, automated data link between NASTRAN finite element models and mass properties databases. This paper describes the program specifications, capabilities, architecture, and methodology used in the development of MPPLOT and MASDIS. It also describes the goals and rationale used in the development of these programs.},

keywords = {12. Weight Engineering - Computer Applications},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1890,

title = {1890. Mass Properties Database Model Verification and Finite Element Model Mass Distribution},

author = {J W Pieper and J H Nakai},

url = {https://www.sawe.org/product/paper-1890},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {The General Dynamics Space Systems Division Mass Properties Group is in the process of incorporating two recently developed computer programs into their technical analysis. These programs are used in the preparation of nodal mass distribution for finite element structural analysis and in the verification of a mass properties database. This paper describes the need for, the use of, and the benefits gained from employing the Mass Properties Model PLOTter (MPPLOT); and the nodal mass distribution program, MASs DIStribution (MASDIS) on the Apollo computer.},

keywords = {12. Weight Engineering - Computer Applications},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1888,

title = {1888. Minimum Weight High Tempterature Joint Design for Reentry Vehicles},

author = {W F Tidd},

url = {https://www.sawe.org/product/paper-1888},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {29},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {High temperature joint design is a subject which has been receiving increased attention as a result of the ongoing national effort to advance hypersonic and materials technologies. Current fastener technology is sufficient for temperatures below 1600' F, but the development of advanced carbon/carbon (ACC) has created a need for a robust fastening system which can maintain reasonable strength up to temperatures of 3000' F. High temperature fastener data is limited, and there is a significant need for additional research and development The objective of this paper is to provide directional input to this future work in the form of minimum weight carbon-carbon splice joint design estimates for a given range of load and temperature conditions. The data presented in this paper is based on an analytical model of a single shear C/C splice joint which was evaluated for running loads ranging from 200-4000 lb/in and temperatures ranging from 78-3000' F. Minimum weight designs were identified at finite intervals within these ranges through an iterative optimization of the major design variables: fastener material, fastener spacing, fastener diameter, panel thickness, and the number of fastener rows. Sixteen different fastener materials were evaluated in the optimization including among others: T-222 tantalum, C129Y columbium, TZM, carbon/carbon, and tungsten hafnium carbide. The results of this analysis indicate that for joint loads of less than 1000 lb/in and temperatures greater than 1800' F, the minimum weight design includes C/C as the fastener material. Joints with loads greater than 1000 lb/in and temperatures between 1800 and 2200' F should be designed using T-222 tantalum or TZM. Tungsten hafnium carbide yields the minimum weight design for joints with loads greater than I 000 lb/in and temperatures greater than 2200' R. The subject of high temperature carbon-carbon joint design includes many issues, of which weight is only one. Oxidation protection, thermal expansion, and a variety of other material and design problems must be considered in the development of a robust high temperature fastening system for carbon/carbon. This paper represents an effort to quantify the weight impacts of various design decisions, and thereby provide input to the future testing and development of high temperature fastener materials.},

keywords = {22. Weight Engineering - Structural Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1887,

title = {1887. In Flight Demonstration of Mass Properties Identification and Jet Plume Interaction on the Aero Assist Flight Experiment},

author = {E V Bergman and R C Blanchard},

url = {https://www.sawe.org/product/paper-1887},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {23},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {Algorithms for in-flight demonstration of spacecraft mass, center of mass, and inertia matrix have been developed. These algorithms are intended to provide the capability to autonomously measure mass properties as they change in-flight due to consumable expenditure, payload deployment and retrieval, and docking. Prior to serious consideration of these algorithms for actual spacecraft applications, it is highly desirable to test their performance in an actual flight environment. The mass properties estimator is a second order, nonlinear filter which resembles an extended Kalman filter. It contains a model for the dynamics of a rigid spacecraft with the mass properties as parameters. When jets are fired, that model is used with the current estimate of mass properties to predict the output of rate gyros and accelerometers on the spacecraft, and that prediction is compared to actual measured values. The filter operates on this comparison to revise its estimate of spacecraft mass properties. Simulation results indicate that the vehicle inertia matrix, center of mass, and mass can be determined by a sequence of eleven individual jet firings. Starting with arbitrary numerical values for each parameter, the mass properties can be determined to better than 1%.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1886,

title = {1886. Estimating Moments of Inertia for Advanced Manned Launch Systems},

author = {Ian O. MacConochie},

url = {https://www.sawe.org/product/paper-1886},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {22},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {In the conceptual design of new spacecraft, weight and center of gravity are usually adequate for determining the size and location of the wing for flight, but moments of inertia are sometimes needed if the vehicle is to be assessed for controllability. Techniques are proposed for approximating the moments of inertia of subsystems in a reasonable time, with reasonable accuracy, by estimating radii of gyration.},

keywords = {18. Weight Engineering - Spacecraft Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1884,

title = {1884. CG Measurement Error Analysis - New Technology Has Changed All the Rules},

author = {Richard Boynton and K Wiener},

url = {https://www.sawe.org/product/paper-1884},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {28},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {This paper re-evaluates the basic methods for measuring center of gravity in light of the dramatic innovations in force measurement which have taken place in the last few years. The authors attempt to include all sources of error. These include the ability of the test operator to reliably determine the position of the unit under test relative to the reference datum of the instrument (''fixturing error''), effect of instrument lean, sensitivity (the smallest cg shift which can be detected), and linearity. The type of cg instruments analyzed are: the gas bearing rotary table moment measuring concept (using both load cells and the new active moment transducers), the multiple point weighing method (''three load cell method''), the moment of inertia method, mechanical rebalance methods, and spin balance cg determination. Typical errors for different test objects are determined, and recommendations are made for different applications. The authors conclude with an error summary of current available cg measuring instruments.},

keywords = {03. Center Of Gravity},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1883,

title = {1883. State of the Art Mass Properties Lab},

author = {J Garcia},

url = {https://www.sawe.org/product/paper-1883},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {27},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {This paper describes the state of the art Mass Properties Laboratory at the McDonnell Douglas Helicopter Company in Mesa, Arizona. The lab's prime capabilities include: weight and center of gravity measurement; static balancing of helicopter main rotor blades; inertia measurement; and dynamic balancing of helicopter rotor hubs, complete tail rotor assemblies, and NOTAR (No Tail Rotor) fans. The theory behind the operation of each system as well as its basic requirements is described in detail. These requirements involve accuracy, repeatability, linearity, simplicity, maintainability, calibration and temperature correction, and size and weight limits. The mass properties lab and its features are the result of management foresight and cumulative years of experience in mass properties engineering. This lab, along with the entire Advanced Development Center in which it is housed, demonstrates the commitment of McDonnell Douglas Helicopter Company to be on the leading edge of technology.},

keywords = {09. Weighing Equipment},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1882,

title = {1882. Aircraft Platform Scales Without Sideload Induced Weighing Errors},

author = {E Studlien},

url = {https://www.sawe.org/product/paper-1882},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {8},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {Since the introduction of electronic load cells in aircraft weighing, sideload errors have plagued the industry. Sideload errors are simply inherent in most, if not virtually all, load cells and little could really be done about it - until the advent of the Metrox Platform. In the early part of this decade, North American Rockwell developed a requirement for an all-new state-of-the-art platform scale system for the B-lB Bomber. Metrox won the contract to design and build a platform system to these stringent requirements. Initial tests of the first platforms built for the B- I B program once again revealed the old bug-a-boo-sideload errors. The sideload problem was eliminated by re-designing the load beam mounting. Instead of a fixed, solidly bolted load beam, it was mounted so it could ''float''.},

keywords = {09. Weighing Equipment},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1881,

title = {1881. Lockheed Missiles and Space Company Mass Properties Facility},

author = {G Strom},

url = {https://www.sawe.org/product/paper-1881},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {17},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {This paper describes the mass properties balancing facility constructed in 1987 at Lockheed Missiles & Space Co. in Sunnyvale, California. The balancing machine is a Schenck-Trebel model E6/MOI-7. The capabilities and operational procedures of the machine are described. To speed up the determination of balance weights required, a program was written for a Macintosh SE computer. The capabilities of this program are outlined.},

keywords = {09. Weighing Equipment},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1880,

title = {1880. The Effect of Entrapped Air on Moment of Inertia Measurements},

author = {G Jones},

url = {https://www.sawe.org/product/paper-1880},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {46},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {At the 1987 International Conference of the Society of Allied Weight Engineers, the point came up that the effect of ambient air on moment of inertia measurements was an area that needed further study. Since China Lake NWC Environmental Engineering Branch, headed by Steven N. Tanner, owns a large vacuum chamber, I undertook to do some moment of inertia measurements with the effect of ambient air removed. This study led to the derivation of a formula for estimating the effect of ambient air on moment measurements. I also discovered some valuable techniques for performing measurements on low mass density items, test items with very small moments of inertia and test items with moments of inertia larger than the advertised maximum measurement capability of the Space Electronics KGR 300. I will state the most important findings right up front: The formula for estimating the moment of inertia contributed by entrapped ambient air is given by Iea = r/45 (L^3.5)(H^l.5) where the test object is a rectangular plane, r is the density of the ambient air, L is the length of the plane, H is the height of the plane. I call this relationship Spike's rule for determining entrapped air moment of a planar solid.},

keywords = {05. Inertia Calculations},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1878,

title = {1878. The Weight Improvement Process as an Element of Weight Control},

author = {K Klink},

url = {https://www.sawe.org/product/paper-1878},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {30},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {One approach for attaining a successful weight control effort is to center it around a ''high visibility'' weight improvement program. In addition to normal weight performance tracking and reporting, an intensive effort should be initiated early on to solicit weight improvement suggestions. Weight reduction can be accomplished through positive employee motivation and without traditional methods of target weights, monthly goals, crash reduction programs, etc. The Weight Improvement Program (WIP) philosophy is to give praise, challenge requirements, set goals, report progress, and unleash human potential throughout the design process. Positive motivation and the creative energy of every individual on the project is an integral part of the weight control process.},

keywords = {10. Weight Engineering - Aircraft Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1877,

title = {1877. Weight Control of a Large Space Booster},

author = {G R Matheny},

url = {https://www.sawe.org/product/paper-1877},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {25},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {The Titan III had successfully performed many missions placing satellites in orbit from both coasts. The challenge was to design a longer ''stretched'' vehicle by lengthening the fuel and oxidizer tanks on both stages while holding the diameter constant at ten feet. The new Titan IV vehicle would have to withstand larger P-equivalent loads due to the increased weight required by structural beefup to the skin, stringers, and frames. Different sections of the vehicle were assigned different amounts of beef-up based on their relative axial load-carrying capabilities. An initial design vehicle was established. Upon further analysis, it was determined that the increased vehicle and payload fairing lengths imparted a large bending moment on the booster at design Q-Alpha-Total flight conditions. This caused a vehicle redesign, and it was found that stiffness rather than axial load became the design driver in most areas. As the new stiffness requirements were translated into structural detail sizing and analyzed by the mass properties group, the weight problems began to surface Target weights had been established in the proposal phase and revised due to the stiffness criteria, but both values were being exceeded in design. A method to control vehicle weight was urgently needed. The paper discusses how this challenge was met by analyzing critical frames, stringers, and skins with a target weight versus stress margin comparison. Details are presented to show how items became identified for weight reduction and results are quantified. A significant performance gain resulted from this weight reduction program. The excellent teamwork that produced the weight savings has carried over into subsequent phases of vehicle development. Various design groups were united by this effort, and for a while everyone became a ''weights engineer'' and worked for a common goal.},

keywords = {14. Weight Engineering - Missile Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1873,

title = {1873. Rotocraft Weight Trends in Light of Structureal Material Characteristics},

author = {C Ingalls and W Z Stepniewski},

url = {https://www.sawe.org/product/paper-1873},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {35},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {Variations in the weights of rotorcraft and their components due to advanced materials use are the topics of this study. The impact of new materials on component weights is illustrated by historical weight trends. The influence of structural material characteristics on the relative weight levels of rotorcraft components, the weight effectiveness, for both static and cyclical loadings is reviewed. Cursory expressions are developed to permit estimation of the effect of structural material strength effectiveness values on component weights. Special constraints which could limit possible weight reductions are considered briefly. Advanced structural materials that exhibit superior weight reduction potential are identified.},

keywords = {10. Weight Engineering - Aircraft Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1872,

title = {1872. Helicopter Weight Torque Advisory System},

author = {R L Adelson},

url = {https://www.sawe.org/product/paper-1872},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {The helicopter weight and torque advisory system is an onboard avionics system that combines cargo hook load weight information with temperature, altitude, and fuel weight to compute optimum performance data for display to the pilots. The system assists the pilots in obtaining maximum cargo carrying capability while enhancing safety, reducing maintenance costs, and extending the life of the helicopter. Boeing Military Airplanes developed and built an engineering model of the system as an independent research and development project. It was reduced to practice in the laboratory and later installed in a U.S. Army CH-47 test helicopter to demonstrate its features and capabilities. Details on the model are included in U.S. Patent 4,780,838 issued to The Boeing Company October 25, 1988. The system features are generic and adaptable to different types of helicopters. It can be incorporated into or used with other avionics system components. It can also he a stand-alone system with its own dedicated processor, control panel, and display. The Weight and Torque Advisory System (WTAS) also includes a means to account for internal payload and its distribution for weight and balance calculations. This feature, coupled with the capability to account for expendable items such as stores and munitions, as well as fuel distributions, addresses the parameters necessary for weight and balance control during flight.},

keywords = {02. Aircraft Loading - Payload},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1871,

title = {1871. Technical Logical Forecase of VTOL Weight Empty Fraction in the Year 2020},

author = {J E MacLennan},

url = {https://www.sawe.org/product/paper-1871},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {38},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {Keeping the weight empty to gross weight ratio (referred to hereinafter as weight empty fraction) as low as possible is one of the most important factors in creating an operationally efficient vehicle as far as load carrying activities or time on station is concerned. Historically, new technology weight reduction benefits have allowed improved aircraft attributes and mission capabilities while maintaining a fairly constant weight empty fraction. Obviously, aircraft analysts and designers need to know the trend of weight empty fraction versus time and to understand the factors which cause this trend. More interesting would be the ability to predict weight empty fraction ten or more years in the future. Will the fraction remain at its present value, where it has stayed for the past twenty years, or will a new curve develop? Are enough weight saving technologies available to offset the trend of ever increasingly more stringent aircraft requirements? Some of the emerging technologies influencing VTOL design are the all glass cockpit, bearingless main rotor, composite airframes. digital optical flight control systems, improved drive systems, innovative anti-torque systems, and advanced technology engines. Offsetting the weight benefits of some of these technologies are the requirements for radar/laser warning, nuclear hardening, improved maintainability, low observability, increased agility, NBC protection, and target identification under all weather conditions.},

keywords = {30. Miscellaneous},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1857,

title = {1857. Estimating Life Cycle Cost},

author = {D Horning},

url = {https://www.sawe.org/product/paper-1857},

year  = {1988},

date = {1988-05-01},

booktitle = {47th Annual Conference, Plymouth, Michigan, May 23-25},

pages = {53},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Plymouth, Michigan},

abstract = {Life Cycle Cost (LCC) is becoming an increasingly important element in the development and selection of aircraft programs. It is used by both industry and the customers to evaluate and select between alternatives. It is also used as a primary selection criteria for trade analysis since it is the only factor that combines all other elements of the program with a single value. Primary significance occurs between the application of resources in the aquisition phases and the resultant cost of operation over the life of the program. The models used to estimate the LCC must provide reasonable costs in which there is considerable confidence by both the contractor and the customer. It must be developed at a level which can provide significance between alternate configurations, systems and equipments and operational modes. LCC as presented in this paper is developed parametrically using hours and material dollars as independant variables and cost driving configuration and program factors as independant variables. These variables are incorporated into cost estimating relationships (CERs) using statistical multiple regression analysis. the CERs take the form of HOURS = C * V1^E1 * V2^E2 * V3^E3 * V4^E4 where V is the independant varible and E is the exponent. As will be seen, size is a predominant variable when considering a broad spectrum of aircraft types. Weight consistently provides the highest correlation coefficients as a proxy for size and is used throughout the model. The group level weight statement is generally used. With the increasing use of advancedmaterials, with their reduced weight, it must be remembered that the historical aircraft used in the databases are primarily metalic and therfore, since size (weight proxy) is a predominant variable the composite weights must be translated to the equivalent metalic weight. In developing LCC the interaction between the weight engineer and LCC analyst is critical. Both must totally understand the configuration and the LCC analyst must completely understand the weight statement since it tends to provide much of the configuration definition. Many of the elements of LCC must be adjusted for advanced materials and technologies and program peculiarities. These adjustments come from consultation with weight engineers and other technical personnel and require a close and continuing interface with them. The LCC estimates for future programs can be no better than the judgments related to weights and other advanced requirements. The LCC is continually reviewed and refined throughout the developement process, as is the configuration and the weight.},

keywords = {29. Weight Value-Of-Pound},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1856,

title = {1856. Cost Estimating Methods for Advanced Space Systems},

author = {K Cyr},

url = {https://www.sawe.org/product/paper-1856},

year  = {1988},

date = {1988-05-01},

booktitle = {47th Annual Conference, Plymouth, Michigan, May 23-25},

pages = {16},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Plymouth, Michigan},

abstract = {The National Aeronautics and Space Administration (NASA) is responsible for developing much of the nation?s future space technology. Cost estimates for new programs are required early in the planning process so that decisions can be made accurately. Because of the long lead times required to develop space hardware, the cost estimates are frequently required 10-15 years before the program delivers hardware. The system design in conceptual phases of a program is usually only vaguely defined and the technology used is often state of the art or beyond. These factors combine to make cost estimating for conceptual programs very challenging. This paper describes an effort to develop parametric cost estimating methods for space systems in the conceptual design phase.},

keywords = {29. Weight Value-Of-Pound},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1855,

title = {1855. Using Cost Weight Curves in Parametric Cost Predictions},

author = {B Barrus},

url = {https://www.sawe.org/product/paper-1855},

year  = {1988},

date = {1988-05-01},

booktitle = {47th Annual Conference, Plymouth, Michigan, May 23-25},

pages = {58},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Plymouth, Michigan},

abstract = {The goal of this paper is to suggest a methodology of using cost-weight curves to make better cost estimates employing improved technologies. The methodology involves logarithmic regression analysis of categorized ized historical cost, weight, and performance data over time for a selected system. New system performance requirements are thereafter used as predictors for adjusting the slope and y-axis intercept of the cost-weight curves. The curves are used to make the cost estimate, based upon the estimated weight of the new system. As a test, automobile average fuel economy standards are regressed against cost-weight curves of 1970 through 1980 model year Oldsmobile 2-door coupes. The resulting cost model is then used to predict the cost-weight curve for 1983 model year Oldsmobile 2-door coupes. Interesting parametric patterns are revealed which may have widespread application, although further analysis is required. The resulting prediction curve misses the target cost measurement by -7.6%.},

keywords = {29. Weight Value-Of-Pound},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1854,

title = {1854. The Importance of Weight in Changing a Cost Estimating Environment},

author = {L W Gordon},

url = {https://www.sawe.org/product/paper-1854},

year  = {1988},

date = {1988-05-01},

booktitle = {47th Annual Conference, Plymouth, Michigan, May 23-25},

pages = {21},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Plymouth, Michigan},

abstract = {Until recently, bottoms-up has been the primary method of cost estimating in the aerospace industry. Parametric estimates were used internally only for trade studies and should-cost analyses and were not submitted with the proposal. Lockheed is working to reverse the cost estimating process, i.e., parametric as the primary method and bottoms-up as the last resort. This paper presents one such method and addresses how yesterday?s databases can be adjusted for today?s technology. This paper is intended to demonstrate that parametric cost estimating is being implemented as a primary method and, as a result, weight as a cost driver is extremely important.},

keywords = {29. Weight Value-Of-Pound},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1850,

title = {1850. The Use of Fiber Reinforced Thermoplastics as a Primary Structure on the McDonnell Douglas AH-64 Apache Helicoter},

author = {G S Thierstein and D W Huff},

url = {https://www.sawe.org/product/paper-1850},

year  = {1988},

date = {1988-05-01},

booktitle = {47th Annual Conference, Plymouth, Michigan, May 23-25},

pages = {15},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Plymouth, Michigan},

abstract = {New generation aircraft structures need to be lighter in order to allow for more sophisticated avionics and weapons systems.. The increased use of lightweight, thermoset composite materials has partially addressed this dilemma. However, thermoset composites possess certain undesirable characteristics, including brittleness and a variety of manufacturing, storage, and processing limitations. On the other hand, new fiber reinforced thermoplastic (FRTP) composite materials offer many of the advantages of advanced thermoset composites, including reduced weight and higher fatigue life. However, unlike thermosets, they possess high toughness, unlimited shelf life, and can be reprocessed and spliced/combined together to reduce scrap. To explore these materials, an evaluation program was performed at McDonnell Douglas Helicopter Company with the objective of replacing an existing, primary, metallic structure on the AH-64 Apache helicopter with an FRTP structure.},

keywords = {27. Weight Reduction - Materials},

pubstate = {published},

tppubtype = {inproceedings}

}