1026. Procedure for Evaluating Stability Required for Emergency Undocking of Nuclear Submarines During Destructive Weather

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Paper Title: 
1026. Procedure for Evaluating Stability Required for Emergency Undocking of Nuclear Submarines During Destructive Weather
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I regret to inform you that S.A.W.E. Paper No. 1026 \Procedure for Evaluating Stability Required for Emergency Undocking of Nuclear Submarines During Destructive Weather\,authored by Mr. R. L. Beach of Charleston Naval Shipyard, Charleston, South Carolina, was not cleared for public release. However,a copy of the paper is available for use within the U. S. Navy establishment. Requests shouldinclude demonstration of the \need to know, and be sent to Commander Charleston Naval Shipyard Charleston, South Carolina 29408 Contractors desiring a copy of the paper should make requests directly to their Navy Contracting Officer for verification of security clearance and \need to know\. Sincerely yours, Department of the NavyNaval Ship Systems CommandWashington, D.C. 1974 1 10 0 3754 6402 SAWE1026.pdf 739 SAWE1026 Papers papers/1026/buy SAWE1026
1027 1027. Weight Margins, A Design Parameter for Undersea Vehicles Defined weight margins are relatively new to the submersible design field. They have come into general use onlyrecently with advanced submarine designs. Weight margin refers to a design \tool\ now attaining a high degree ofsophistication, but often confusing to designers who have not been involved directly in a program of design weightcontrol.Based on the premise that a technical paper is primarily an educational aid, the objective of this dissertation isto provide technical designers with a working knowledge of intricate margin effect computations. Also given isgeneral background information on the development of margin to its present level of requirement in a submersible vehicle design package.Except for the section on computations, the material is presented in narrative form covering history, necessity,source, and amount. Included is a graphic representation of the classification of margin types into the four groupsusually reported on current military submersible design controls.Security restrictions preclude reference to any specific defense design or contract, but historical backup for thestatements in this paper exists in the record files of: (a) The Electric Boat division of General Dynamics, Groton, Connecticut (b) Supervisor of Shipbuilding, Conversion and Repair, USN, Groton, ConnecticutThe establishing of definite rules for the determination, allocation, and disbursement of weight margins has beendeterred by an insufficiency of historical data. Weight control for submersible vehicles is a new technology that must be built up block by block on the firm foundation of experience. 1974 11 10 0 3755 6403 SAWE1027.pdf 726 SAWE1027 Papers papers/1027/buy SAWE1027
1028 1028. Weight Control on a High Performance Craft This paper describes the weight control program, and results, on a new high speedfast patrol boat,the Coastal Patrol and Interdiction Craft. The Coastal Patrol and Interdiction Craft, called CPIC, is a 100 foot, high performance combatant craft. Weight (and displacement) of combatant craft is critical to successful performance. The CPIC was designed to carry a specific weapon system and has a specific missionprofile. Growth in displacement would seriously impact on the engine power required and impact on the size and cost of the craft. Differences in the design weight andconstruction weight estimates were sufficient to question the adequacy of the mainpropulsion system with regard to speed, endurance and the attendant engineering review became most significant. The weight control efforts and results are described with a general overview of the project. No contract requirements existed for stringent weight reduction performance. The methods by which control was developed on the existing contract are discussed, and observations provided for consideration in developingimproved control methods. 1974 14 10 0 3756 6404 SAWE1028.pdf 740 SAWE1028 Papers papers/1028/buy SAWE1028
1029 1029. The Outlook for Lighter Structures in High Performance Marine Vehicles Structural weights of existing high performance marine vehicles, principally hydrofoil craft, are examined to determine the design or geometric parameters that have significant effect. For total structural density areshown to be governing. Similarly, the governing parameters and the loads which determine scantlings, where known, are compared to develop measures of efficient use of structural material. These figures of merit are applied to a number of existing high performance marine vehicles and projections of what might be attainable in the future are made. 1974 12 10 0 3757 6405 SAWE1029.pdf 733 SAWE1029 Papers papers/1029/buy SAWE1029
1030 1030. Advanced Composites and Their Application to Hydrofoils Over the past 10 years, significant progress Following a brief review of the advanced composites and their application to structural components of aircraft, missiles, and space vehicles, studies are presented on potential applications of composites to various structural components of hydrofoils, including decking, hull, foils, and strut. It is shownthat application of various composites to the hull and decking of a hydrofoil can yield a weight saving of 16 to 51 percent whereas application of composites to struts and foils shows potential weight savings of ~60 percent compared to steel counterparts. Results are also presented on cost effectiveness of composites as applied to hydrofoils. 1974 15 10 0 3758 6406 SAWE1030.pdf 746 SAWE1030 Papers papers/1030/buy SAWE1030
1031 1031. Structural Weight Determination for SWATH Ships This paper briefly describes a series of structural design and weight estimating procedures forSWATH ships. Since very little prior knowledge exists in the area of reliable prediction of appliedloads, precise design procedures, and typical scantlings, studies were conducted to develop adequate structural design methods. These range In complexity from gross weight fraction approximation, to a volumetric density method, to an area density method developed for use in a SWATH Feasibility Synthesiscomputer program, and finally to a more detail structural design using a modified version of the computer program, Midship Section Design for Naval Ships. The effects on the structural weight of varying geometry, sea-induced loads, local loads, and of changing the primary construction material to other higher strength steels and/or aluminum alloys are presented. The assumed loads are cited, and the need for better localand overall load definition is discussed. Opinions of the merits and shortcomings of these procedures are given. 1974 14 10 0 3759 6407 SAWE1031.pdf 748 SAWE1031 Papers papers/1031/buy SAWE1031
1032 1032. Automated Weight Manifest - A Discussion NULL 1974 8 10 0 3760 6408 SAWE1032.pdf 732 SAWE1032 Papers papers/1032/buy SAWE1032
1033 1033. An Oleo Settling Weight and Balance System The development of a high reliability pressure type Weight and Balance system, with accurate static reading capability,is the result of four years of intensive investigation by Canadian Marconi Company into the general problem of on-boardweighing systems for aircraft. Beginning with the installation of a simple pressure system on a Canadian Air ForceFanjet Falcon in 1972, the program has now advanced to an accumulation of measured data on almost all major aircrafttypes, including the Lockheed C-130 and L-1011, McDonnel Douglas DC-8 and DC-9 and Boeing 707, 727, and 747 aircraft,using the olea pressure curve technique.The simple pressure type Weight and Balance system operates on the principle of measuring the static pressure of eachof the aircraft oleos, and electronically multiplying by the known oleo piston areas to determine the force acting oneach of the landing gear. The system thus consists of a set of pressure sensors and a computer/display unit. Take-offGross WEight (TOGW) and Center of Gravity (% MAC) are automatically computed from aircraft constants. The two main advantages of this type of system are: (1) ease of installation (2) low maintenanceThe first advantage derives from the fact that the sensor can be installed via the existing charge valve opening and cantherefore be easily retrofitted on all aircraft types. The second advantage derives from the fact that pressure sensorshave been proven to be much more stable than strain gauge sensors* thus requiring little maintenance.The major disadvantage of the simple pressure system is that it is subject to large and unpredictable errors due to oleofriction.Accordingly, Canadian Marconi Company has developed an advanced pressure system which can measure, and electronicallycancel friction force error while the aircraft is in static condition,*Comments on strain gauge instability errors in the C-7A and on the 747 and DC-10 aircraft can be found in SAWE Paper No 881 by Lieutenant Colonel Edward Low, and in Kit No. 8 of the 1973 Avionics Maintenance Conference report. 1974 7 10 0 3761 6409 SAWE1033.pdf 764 SAWE1033 Papers papers/1033/buy SAWE1033
1034 1034. What Can a Ground Weighing System Do for Us? This paper has been written to more specifically define the use of electronic weighing equipment for industry; and, in particular, the aircraft industry. The primary systems used by airlines are the load cell kits which fit on top of aircraft jacks. The newer systems are platform scales, onto which the aircraft is towed. The platform scales are used specifically for not only total weight and center of gravity, but also calibration of the on-board weighing equipments found primarily in the new wide-bodied aircraft. Additional electronic scale systems are now being installed for the cargo weighing, as well as individual baggage and sorting systems within the terminal. This is to assist direct computer input and data enhancement. The application of the new electronic scales is very important; primarily because they are portable, they have accuracies of .l%, and they can be easily used in different locations by inexperienced operators. A bad weight is typically worse than none at all; therefore, the application and use of the electronic scales is of great importance. At stake is the optimum use and safety of aircraft. 1974 28 17.64 0 3762 6410 SAWE1034.pdf 723 SAWE1034 Papers papers/1034/buy SAWE1034
1035 1035. Equipment Problems of the Third Level Airplane The modern aircraft being produced by general aviation manufacturers today are helping transport people and goods inschedule airline type operations. The commuter airline has become a dependable third level in the air transportbusiness since its mushrooming growth from shaky start just a few years ago. The highly developed turbine-propellerengines and airframes of today's general aviation airplane are helping make real growth possible for the commuteroperator.The purpose of this paper is to review the problems that third level operators have had obtaining the rightequipment for their particular operation. Although this paper just scratches the surface with respect to allequipment used and needed, hopefully it will open some new avenues of interest to the reader. 1974 28 17.64 0 3763 6411 SAWE1035.pdf 747 SAWE1035 Papers papers/1035/buy SAWE1035
1036 1036. Applications for the Air Cushion Landing System The Air Cushion Landing System (ACLS) operates basically on the same ground effectsprinciple as air cushion vehicles, utilizing a layer of air in lieu of wheels as theground contacting medium. A large elliptical shaped \trunk\ resembling an elongatedinner tube encircles the bottom of the fuselage. The bottom of this trunk has a large number of vent holes through which air passes to form the air cushion. When not in use as a landing system, the elastic trunk automatically retracts snuggly against the fuselage. Due to the very low ground overpressure, the ACLS permits aircraft to operate routinelyfrom unprepared surfaces such as dirt, snow, swamps, mud and even water. The project is a 50/50 joint development effort between Canada and the USAF. Canada is providing a modifieddeHavilland Buffalo aircraft, USAF designation -XC-8A. The USAF is providing the ACLS and performing the majority of the flight tests. 1974 23 14.49 0 3764 6412 SAWE1036.pdf 751 SAWE1036 Papers papers/1036/buy SAWE1036
1040 1040. Wing Aeroelastic Structural Analysis Applied to the Study of Fuel-Conserving CTOL Transports The current and continuing energy crisis points out the need for minimizing the fuel burned for a given mission by any new aircraft. Two major design decisions which impact the fuel economy and airplane efficiency are choice of wing geometry and cruise speed. This paper is intended to help in understanding the potential payoff from the careful selection of theseinterrelated design parameters. To accomplish this task, wings with advanced technology airfoils and aerodynamic aspect ratios ranging from 9 to12 were evaluated at cruise Mach numbers of 0.7 and 0.8. Variouswing sweep and thickness combinations and small cruise Mach number perturbations were studied at the selected Mach number to ensure proper wing design refinement for an efficient, fuel conserving airplane. It was decided that existing statistical/parametric weight prediction methods were inadequate for the controlled evaluation of wing geometry parameters over the extreme limits of interest in this study.Therefore, the wings were defined sufficiently to provide detailed geometrical data for aeroelastic structural analyses. Thirty flight and ground design load conditions were analyzed for each wing, and critical design conditions were identified at each span wise analysis station. Structural wing box weights were generated within a computerized analysis program, and complete structural wing weights were obtained with secondary structure and non-optimum accounted by statistical/parametric methods.Flutter and fatigue increments were obtained externally and added to the strength-designed wing weight. These wing weights and their respective aerodynamic efficiencies were incorporated in airplane mission performance analyses. Wing area, flight gross weight, and engine thrust were sized to perform a constantpayload/range mission for each wing geometry and Mach number studied. A configuration was selected based on the best fuel economy and lowest direct operating cost. The selected fuel and cost conserving wing design was characterized by a quarter chord sweep of 25 degrees, was 8% thick outboard, and was designed to cruise at Mach 0.8. The selected aspect ratio was 12, withaerodynamic benefits of new airfoil technology overcoming the structural weight penalties. Due to detail design and operational requirements outside the scope of this preliminary design study, the fuel and cost savings of 25% (nominal) shown in this paper should be regarded as potential limits of savings possible within the parametric limits examined. 1975 27 17.01 0 3693 6341 SAWE1040.pdf 753 SAWE1040 Papers papers/1040/buy SAWE1040
1041 1041. Methods for the Determination of Gross Weight Several methods for determining gross takeoff weight are discussed. These methods can be described as follows: Statistical plots of gross weight versus significant design parameters. Solution for gross weight of a set of four simultaneous equations, consisting of three performance equations involving gross weight and an equation expressing gross weight as a summation of its component weights. Simultaneously, aspect ratio, wing area and thrust are uniquely determined. Application of the growth factor to obtaining gross weight of a derivative for which the gross weight of the base configuration is known is presented. Forms of the growth factor are discussed in which performance is maintained constant and in which performance is variant. Gross weight is shown to be related to the number of passengers for a wide range of commercial aircraft; and to be related to various parameters such as thrust and payload-range, separately, for two, three and four engine aircraft. With the conception that gross weight is composed of payload, payload accommodations weight, propulsion system weight,components relating to lift and ground requirements, and required fuel weight, and with statistical plots pertainingto each grouping, a simple equation for gross weight is evolved. The classical approach to obtaining gross weight is noted whereby a value for gross weight is assumed upon which the individual component weights are weight derived and then summed; then the final gross is obtained through the convergent iterative process. The limits and means of extending gross weight are discussed. A brief discussion Of optimum gross weights is presented. 1975 43 27.09 0 3694 6342 SAWE1041.pdf 755 SAWE1041 Papers papers/1041/buy SAWE1041
1042 1042. Payoffs From Active Controls Technology Applications - Transport Aircraft A comprehensive mass properties analyses process is essential in determining reliable payoffs for reduced static stability (RSS) and load alleviation and mode suppression (LAMS). This process is discussed as it applies to advance design studies relating to the application of active controls to transport aircraft. Reference is made to the Douglas mass properties estimation system (MAPES) which is a computer program for transport aircraft weight estimation, and is very adaptable to active controls applications. Weight effects to structural components resulting from the application of RSS and LAMS are discussed, as are systems implications. Payoffs are discussed in terms of vehicle range, vehicle size, and increased payload. 1975 13 10 0 3695 6343 SAWE1042.pdf 744 SAWE1042 Papers papers/1042/buy SAWE1042
1043 1043. Fatigue and Damage Tolerance Effects on Preliminary Design Wing Weights This paper presents the results of a study contract funded by the Air Force. The purpose of thestudy was to assess the effect of current design criteria and advanced technology on an existingstructure. The structure chosen for the study was the C-141 inner wing box. The design criteriainclude the new fatigue and damage tolerance criteria which will probably be required on any new Air Force aircraft. The advanced technology includes new materials and new structural configurations. Two alternate box configurations will be presented showing the effects of material properties and cover configurations on the wing weight. An attempt to predict some trends based on these results is also presented. The work reported herein was conducted under Contract F33615-72-C-2165 sponsoredjointly by the Air Force Flight Dynamics Laboratory and by the Air Force Materials Laboratory andpublished in Technical Report AFFDL-TR-73-51. 1975 20 12.60 0 3696 6344 SAWE1043.pdf 752 SAWE1043 Papers papers/1043/buy SAWE1043
1044 1044. Allowable Stress Estimation Methods for Preliminary Design Weight Prediction This paper presents development of allowable stress estimation methods specifically tailored topreliminary design weight prediction. The paper presents a unique analytical technique for projecting test results to cover a large variety of material/temperature combinations, including composite materials. It is shown how this approach overcomes inaccuracies and limitations associated with stress ratioing techniques by providing accountability for material strength limitations such as plasticity. Methods for compression, tension/fatigue and shear are developed. Discussions are limited to primary wing, tail andbody structure. Method application examples are included in the paper. 1975 57 35.91 0 3697 6345 SAWE1044.pdf 756 SAWE1044 Papers papers/1044/buy SAWE1044
1045 1045. Use of Composite Materials for Weight Saving on Aerospace Vehicles A weight saving of 300 pounds has been achieved on the mid-fuselage portion of the Space Shuttle Orbiter by use of boron aluminum composite material in the form of tubular structural members.This application has presented a unique opportunity to study and to some degree, to quantitize theeffects of several factors which often degrade the weight saving obtained by use of composites. Some of the factors which are discussed are, load introduction, geometric factors, maintenance and handling, cost, test data and material properties. Data is provided also on the weight of boronaluminum tubes in terms of load and length requirements and the weight saving which may be achieved by their use. 1975 26 16.38 0 3698 6346 SAWE1045.pdf 760 SAWE1045 Papers papers/1045/buy SAWE1045
1046 1046. Use of Statistics in the Management of Mass Properties A recently developed method has proven useful in efficient management of properties tasks. The method is a statistical analysis for determining potential weight growth. Using data of estimated, calculated, and actual weights from past designs for similar end items, the percent differences between estimated and actual weights and calculated and actual weights we determined and standard deviations calculated. Using tolerance factorsavailable from statistical tables, a family of curves is constructed for each end item showing weight potential growth versus time. The effects of potential weight growth on the useful load is then obtained. It can be determined if the useful load margin is adequate, if changes to the vehicle or software are required, and if the vehicle needs to be weighed. This method has the advantage of showing how the weight growth bf an end item varies with time. 1975 15 10 0 3699 6347 SAWE1046.pdf 731 SAWE1046 Papers papers/1046/buy SAWE1046
1047 1047. Weight Estimation of Manned Spacecraft Metabolic Requirements One of the new problems confronting the weight engineer is the material and energy balanceof the human system loop in the manned spacecraft. This paper presents methods of estimating weight of the crewman's metabolic materialrequirements for a balanced system. The methods are further clarified by an example problem being carried through the analysis for a 50 percentile crewman with a certain daily activity and diet composition. The analysis begins with the problem description of the crewman metabolic material requirementsand material balance. Fundamental to the problem solution is the determination of the metabolicenergy requirements and the metabolic input/output materials to satisfy these requirements. This paper presents methods for estimating the crewman's metabolic energy based on his physicalcharacteristics and activity. Graphs are presented for the crewman's weight and height whileequations are presented for the determination of body surface area which is fundamental to the metabolic energy determination. Food weight estimating equations are presented based on metabolic energy and food composition.Independent chemical oxidation equations of the food constituent (protein, fat and carbohydrate)are presented and used in the determination of oxygen requirement and carbon dioxide and metabolicwater production. Limits in the use of these equations, in regard to Basal Metabolic Rate (EMR)and Respiratory Quotient (RQ) are given. The water balance is presented in weight equations as a function of metabolic energy. The metabolic material weight determinations and system balance is concluded with the determination of fecal waste. Certain weight sensitivity parameters, such as food composition,percentile and metabolic energy and their effect on the metabolic requirements and waste products, are discussed. The discussion concludes with the presentation of a recently patented closed ecological system forextended missions as justification of the importance of this analysis for future missions. Cursorystudy indicating that completely closed ecological systems would be required for mission overapproximately 3-3/4 years, from a weight and economic standpoint. 1975 28 17.64 0 3700 6348 SAWE1047.pdf 742 SAWE1047 Papers papers/1047/buy SAWE1047
1048 1048. Flight Test of a Spin Parachute for Use With a Super Arcas Sounding Rocket A specially configured 16.6-foot (5.1-meter) Disc Gap Band (DGB) Spin Parachute has been designed,developed, integrated with a modified Super Arcas launch vehicle, and qualified by flight testing. The total payload weight, which includes the Spin Parachute and a scientific payload, was 17.6pounds (7.99 kg). Total liftoff weight was 100.3 pounds (45.54kg). The Super Arcas vehicle wasdespun from 18.4cps, 127.3 seconds after launch. Payload separation occurred one second later at an altitude of 244,170 feet (74.4km). The Spin Parachute and payload attained a maximum spin rate of 2.4cps approximately 97 seconds after payload separation. The total suspended weight of the SpinParachute and payload was 14.64 pounds(6.65kg). This Super Arcas vehicle contained several innovations which were necessary to provide mission supportfor the scientific payload. These included the first despin of the Super Arcas vehicle and the firsthigh-altitude deployment of a Spin Parachute. 1975 22 13.86 0 3701 6349 SAWE1048.pdf 749 SAWE1048 Papers papers/1048/buy SAWE1048
1049 1049. Apollo Soyuz Test Project Weights and Mass Properties Operational Management System The Apollo Soyuz Test Project (ASTP) Weight and Mass Properties Operational Management System was established to assure a timely and authoritative method of acquiring, controlling, generating, and disseminating an official set of vehicle weights and mass properties data. These data areutilized by NASA and contractor operational elements in support of the join tUnited States-Russianspaceflight that is to be conducted in July of 1975. This paper provides an overview of the system and its interaction with the various aspects of vehicle and component design, mission planning, hardware and software simulations and verification, and real-time mission support activities. The effect of vehicle configuration, design maturity, and consumables updates will be discussed in the context of weight control. A discussion will be presented of the computerized mass properties input reporting system and theoutput generation technique, which use the input data in the classical mass properties equations tomodel fluid systems and inert modules and thereby produce semi-automatic data updates. The utilization of ASTP operational mass properties data in the areas of Mission Planning, Flight Crew and Flight Controller training, hardware and software evaluation and verification, and real-time support will also be addressed. Finally, the ASTP Mass Properties System reports and the operational data exchange system,which influence prelaunch and real-time management decisions, will be summarized. 1975 28 17.64 0 3702 6350 SAWE1049.pdf 741 SAWE1049 Papers papers/1049/buy SAWE1049
1050 1050. Approximating Inertia Uncertainties for Satellite Flat Spin Analysis Inertia parameters discussed in this paper are the spin to transverse ratio and the difference in transverse moments of inertia. Equations derived in this report will yield approximate uncertainties for the inertia parameters for flat spin analysis of dual spin spacecraft. These uncertainties must have the independent and dependent elements correlated and/or cancelled to be of value. The uncertainty of the spin to transverse ratio when applied to the nominal value gives a confidence level relative to the critical ratio of 1.00. The uncertainty of the difference in transverse moments of inertia when applied to the nominal value and compared to the torque that a dual spin spacecraft de-spin motor can supply gives insight as to whether that spacecraft can be recovered from a flat spin. In the past, both uncertainties were estimated without separation of independent and dependent variables, yielding highly inaccurate values in most cases. The generally high inaccuracies imposedconfining restrictions on the mass properties engineer. This could result in unnecessary ballast weight addition or imply that physical measurements are required where calculated values would suffice.Therefore, it is of economical importance that these inertia parameters be accurately estimated. 1975 20 12.60 0 3703 6351 SAWE1050.pdf 736 SAWE1050 Papers papers/1050/buy SAWE1050
1051 1051. Parametric Weight Prediction Method for Spacecraft Vehicle This paper deals with the development of a unique digital computer program to predict the weight of various types of manned spacecraft. The Spacecraft Parametric Weight Computer Program provides the capability of predicting, synthesizing and trading-off weights for mannned spacecraft. Such a program enables rapid disseminator of weight data to support Space Shuttle Vehicle studies.Theprogram is oriented to operate on a selected input data to produce both parametric and design synthesis information. The two-fold objectives of this program is to provide a high quality weight prediction method and parametric weight scaling of manned spacecraft with a reasonably short, economical operation. The main program is formulated with a series of subroutines assembled to simulate the actual sizing and synthesis routines involved in any parametric analysis. Respective iterations are required to accomplish the interrelationships of subsystems with mission and design requirements. This approach is particularly applicable to the math model of the stage for sizing and weight scaling. For example,unit weight equations for structure are replaced by parametric routines for loads and stress computations. The program logic for successive sizing and weighing of the selected spacecraft stage is accomplished by two unique iterative loops. Essentially, the first loop provides for matching of the estimated and computed stage volumes by the application of subsystem packaging densities, expendables and internal payload to dimensional scaling relationships. Another iteration loop involves the applicable performance relationships which utilize the matching of estimated and computed stage mass fraction. Because of the sensitivity to divergence of the mass fraction, three comparison checks are executed. The first check is to determine if the estimated and computed propulsion mass fraction is within a tolerance of matching. The second check to determine if the value of the computed value exceeds the estimated for the stage mass fraction. The third check is accomplished by ensuring that the stage mass fraction is greater than the performance mass fraction. This procedure resets the assumed value in larger increments steps of estimated stage mass fraction until either the computed values matches the estimated or is less than the performancemass fraction. In the event the performance mass fraction becomes greater than the stage mass fraction, the previous estimated value is assumed and systematic reduction in size of the increment is provided until a match of the computed and estimated values, within tolerance, are obtained or a preset indicator terminates the iterations. 1975 31 19.53 0 3704 6352 SAWE1051.pdf 787 SAWE1051 Papers papers/1051/buy SAWE1051
1052 1052. Measurement of the Inertial Properties of the Helios F-1 Spacecraft This paper presents methods of measuring moment of inertia with very high accuracy. The moment of inertia of the Helios Spacecraft about its spin was axis determined by use of a \roll-fixture\ using two sets of crossed flexure pivots as elastic constraints. The test procedure entailed measurement ofsystem oscillation period with each of a set of added moment-of-inertia increments. The tare effect of the fixture was determined a like process by and was subtracted from the gross value to yield the spacecraft roll moment of inertia to an estimated accuracy of 0.2%.\Lateral\ moments of inertia (i.e., about each of three axes normal to the spin axis) were determined by a gravity pendulum method that makes use of the fact that any physical pendulum has a minimal period of oscillation determined by a particular distance from the axis of rotation to the system center of gravity. In situations where a knife-edge support is used, this distance is equal to the system centroidal radius of gyration. In the subject tests, the pivoting action was provided by hardened pins rolling on flat ways. The effect of the finite radius of the pins was considered in deriving the equations of motion, from which an error analysis revealed the criterion for maximum accuracy in determining the square of the centroidal radius of gyration. The swing fixture provided for a number of optional pivot-pin locations giving precisely known distances between successive axes of oscillation. This fixture, with provisions to support the spacecraft, was ballasted to bring itsvertical c.g. close to that predicted for the spacecraft. This ballasting was done not because the test method requires an accurate foreknowledge of specimen c.g. position but, rather, to minimize errors in the parallel-axis transfer term while removing the tare of the fixture. Though the centroidal moment of inertia of the swing fixture was over twice that of the spacecraft, an error analysisof measurements performed on the flight spacecraft showed that accuracies of better than 0.2% were realized for the two lateral principal moments of inertia. The methods presented allow all measurements test to be made with the specimen in an essentially upright position. The vertical center-of-gravity location is derived in the process. Comments are made on the potential importance of aerodynamic effects on measurements made in the earth's atmosphere.It is shown that, for the Helios configuration, these effects must be taken into account by some means to give an assessment of spin stability in the space environment. 1975 16 10.08 0 3705 6353 SAWE1052.pdf 775 SAWE1052 Papers papers/1052/buy SAWE1052
1054 1054. Motivation of Weight Engineers: A Survey In the last four decades, managing people at work has gone through radical changes. Psychologists, sociologists,and management specialists have tried to offer explanations for motivation of the person in industry. Top management, primarily experienced in the art of managing the skilled personnel since early twenties, has carried through the same philosophy of management while dealing with professionals like engineers. Apparently many engineers feel themselves to be different than other skilled workers such as technical, manual, or clerical, and would like to be treated differently. This study was thus undertaken to find out if engineers perceived themselves to be differentthan other skilled workers.A survey questionnaire was designed to determine the perceptual group differences with special emphasis on motivational factors such as approach to job, supervision required, recognition desired, personality traits and kindsof goals. In the same instrument, questions were asked about ratings of satisfaction with conditions of present job and job activities. Though the major focus of the study was on perception of weight engineers, the instrument was distributed among three sample populations, weight engineers, non-weight engineers in weight related industries, and non-weight engineers in non-weight related industries, The data presented on perceptions of supervisory and non-supervisory engineers of three sample populations clearly indicate that professionals feel themselves to be different than other skilled workers and should be treated as such. This study can be useful to top management in making them aware of the perceptions, feelings, expectations, and standards of performance of their professional subordinates. It is useful to the engineers because it gives them a realistic picture of themselves and their peers with regards to the knowledge of their strengths, limitations, attitudes, expectations, and aspirations. This study is of importance to the nation's technical colleges and universities in making them aware of the characteristics of engineers in industry and helping them in curricula planning. Another beneficiary of this study would be the society of Allied Weight Engineers which would know in greater detail the characteristics of its membership and could thus design its international conferences and presentation of papers to cater to these professionals. 1975 20 12.60 0 3706 6354 SAWE1054.pdf 780 SAWE1054 Papers papers/1054/buy SAWE1054
1055 1055. Rotorcraft Technology 1985 - 1990 This paper is the result of literature surveys, personal research and assessment of the direction to which technology is advancing towards the year 1990. It represents an overall projection of Structures, Sub-systems and Equipment, highlighting those specific areas where major advances in the state-of-the-art are anticipatedand how those advances will effect the role of the Weight Engineer. Projection Philosophy is briefly discussed from the standpoint of (i) Evolution - which are logical extrapolations from the known base and (ii) Revolution - which are identified as special events or discontinuities from the logical progression of known technology.The ideal forecasting methodology is the mixing of both subjective and objective thought processes together with ananalytical technique--this is much more reliable because an opportunity is given to input those changes which fallinto the category of intuitive rather than purely analytical. Before we attempt to project the future, we must be sure we understand the present. Technological innovationsresult from changing motivations. This paper discusses briefly the technology achievements to date, then examines the possible sociotechnoeconomic environment of the time period discussed, with its obvious influence on aerospace and in particular the rotary wing field. 1975 23 14.49 0 3707 6355 SAWE1055.pdf 776 SAWE1055 Papers papers/1055/buy SAWE1055
1056 1056. The Challenge of Weight and Balance Control and Design-To-Cost for Y/C-14 Prototype Development The YC-14 is being developed by Boeing for the United States Air Force in a program intended to improve transport airlift capability. Program goals include STQL performance and a significant expansion of tactical payload carryingability within cost constraints. In response, the Boeing YC-14 development objectives include the following: * Demonstrate upper surface blowing (WSB) as an efficient STQL propulsive lift augmentation system * Demonstrate YC-14 utility in expanding tactical airlift capability * Demonstrate YC-14 ability to accommodate unusual (large, heavy) payloads * Prove the ability to meet cost goals The weight and balance control objective on the YC-14 program is to help direct the prototype development in meetingthe program goals. YC-14 prototype design involves significant challenges. Both time and funding are limited fortesting to provide problem solutions. Time is also limited for design layout cycling to achieve best design. Early in design stages the design-to-cost goals required direct involvement at a highly detailed level with few people. YC-14 weight and balance control activities have recognized and successfully dealt with those challenges. The designwork package team concept, utilized on the YC-14 program, is instrumental in providing fast, accurate, and widelydisseminated information early in the design phase. A high degree of weight staff-initiated direction is providing a sound basis for the program decision-making process. 1975 16 10.08 0 3708 6356 SAWE1056.pdf 773 SAWE1056 Papers papers/1056/buy SAWE1056
1059 1059. Weight and Performance Characteristics of Magnetically Suspended High-Speed Trains as Compared to Aircraft MBB is developing in co-operation with Krauss-Maffei a surface transportation system which is designed to cruise at speeds up to 300 mph. The system is using magnetic forces generated by electrical power for lift and cruise propulsion. There is an analogy to aircraft which are using aerodynamic forces to maintain motion through air. The paper comparesthe basic performance characteristics of magnetic and aerodynamic forces relevant for the motion of aircraft and magnetically suspended high-speed vehicles. As a result weight sensitivities are derived for both types of craft. Such weight sensitivities are used as a basis for a comparison of basic economic characteristics. 1975 22 13.86 0 3709 6357 SAWE1059.pdf 778 SAWE1059 Papers papers/1059/buy SAWE1059
1060 1060. Impact of Safety, Energy, and Emission Requirements on Vehicle Design Present and proposed safety, damageability, emission and noise regulations require major compromises in other desirable automobile characteristics. Fuel economy, acceleration, performance and cost all suffer in the design tradeoffs required. As an example, a subcompact vehicle produced for sale worldwide has been experimentally modified to meet U.S. vehicle regulations. The sacrifices in customer perceived values are enumerated. The \chain reaction\ effects of mandated changes which add weight to a car are described and quantified. It is concluded that benefits from motor vehicle design regulations are difficult to measure and a universal need exists for better data upon which to base future safety, damageability, emission and noise regulations. 1975 17 10.71 0 3710 6358 SAWE1060.pdf 788 SAWE1060 Papers papers/1060/buy SAWE1060
1063 1063. Isogrid Weight Optimum Structures Future aerospace missions, vehicles, and payloads, will be increasingly dependent on high-performance, lightweight,Cost-effective structures. Isogrid rates serious consideration in this regard. Here we will describe different isogrid configurations, how they apply to shell and panel structures, and, by way of examples, how cylindrical isogrid shells are analyzed and sized. Design equations and procedures are presented,comparisons are made between different isogrid configurations, and useful preliminary design data is presented. Finally, merits of a Space Tug composite isogrid shell are discussed. Strength and weight are inseparable entities in our treatment of isogrid. We attempt to be analytically comprehensive,accounting for all reasonable local and general instability modes in which isogrid can fail and not overlooking such details as fillet radii and machining mismatches in weights equations. Features of isogrid include: minimum use non-optimum or non-fully-stressed material,low piece-part count especially when it is machined, good post buckling characteristics (isogrid can experience some modes of local failure withoutsuccumbing to general instability), and a minimal space envelope needed shell applications because isogrid structures can be designed without dependance on stabilizing frames. 1975 21 13.23 0 3711 6359 SAWE1063.pdf 795 SAWE1063 Papers papers/1063/buy SAWE1063
1064 1064. Application of Programmable Calculator Systems in Mass Properties Engineering Every engineer is involved daily with some problem which requires the calculation of a numeric answer. These calculations may be very complex or quite long and therefore require the use of a computing device other than a pencil and paper. Many engineers are likely to turn to a computer to solve any calculations more difficult than adding two numbers. However, many day-to-day types of problem solving are difficult and tedious to do by hand, but really don't require the full capability of a computer, In the field of mass properties engineering, these types of calculations may include such things as mass moments of inertia, center of gravity or centroids. For work in the aerospace, shipbuilding or general transportationindustry, engineers may have to continually solve these formulas or others like them. 1975 47 29.61 0 3712 6360 SAWE1064.pdf 790 SAWE1064 Papers papers/1064/buy SAWE1064
1065 1065. Liquid Hydrogen - Fuel of the Future? The domestic and world supplies of petroleum are not unlimited. It is forecast that before the end of the 20th century,world oil production will reach a peak and begin a steady decline. A survey of possible substitute fuels reveals thatliquid hydrogen may be the leading contender to replace petroleum. Already, its potential price per BTU is competitivewith JP fuel. Its greater heat of combustion and its negligible impact on air pollution are also very worthwhileattributes. Liquid hydrogen is compared to petroleum-based fuels for propulsion of various types of vehicles. For supersonicaircraft, a lighter, less costly design can be achieved through the use of this cryogenic fuel. Takeoff weight can bereduced by more than 40%, operational empty weight and cost by more than 20%. For subsonic, medium-range aircraft, takeoff and operational weights can be reduced by 20%and l0%, respectively. A brief review of the methods used to produce this fuel of the future ads to an outline of the ways in which our needsmay be met. For the near term, LH2 can be manufactured from coal or lignite. In the not-too-distant future, nuclearpower of solar collectors cm generate large quantities of hydrogen by electrolysis or by thermochemical splitting ofwater. A comparison of relative hazards shows that LH2 is actually safer to use than petroleum fuels. The rapidly growing air-transportation industry has the most to gain by leading the way into the hydrogen economy andsevering its dependence on a disappearing energy source. After aviation leads the way, hydrogen will readily enter wider industrial and domestic use, making the world a cleaner and therefore a healthier place to live. 1975 43 27.09 0 3713 6361 SAWE1065.pdf 792 SAWE1065 Papers papers/1065/buy SAWE1065
1066 1066. Mass Properties Measurements of Large Objects The measuring and testing of mass properties is not new to the weights engineer. Numerous papers have been presented on methods, procedures, facilities, and analyses of various mass properties tests. However, when confronted with the task of measuring a heavy, outsized object, it is found that most previous experience is with smaller aerospace components. Even so, the theory of moment-of-inertia testing remains constant; it should be simply a matter of applying the same proven test procedure to a larger item, but as will be shown in this paper, there were other considerations. The method of moment-of-inertia testing selected was the bifilar pendulum. The mechanics of the bifilar method seemedmost workable and the measured parameters relatively easy to obtain. The task was to determine the weight, center of gravity, and three-axis (yaw, pitch, and roll) moment of inertia of two similar Boeing747 engine pod buildups, each weighing 4950 kilograms (11040 pounds) in a space envelope about 2.5 meters (8 feet) in diameter by 6 meters (20 feet)in length. Solving the logistics and ground handling problems of such a large and expensive object proved interestingbut uneventful. However, during the first round of tests it became evident that we were at the low end of a learning curve in applying the bifilar pendulum method techniques. In determining the moment of inertia via the bifilar pendulum method, four parameters were measured: filar length, filar radius, system weight, and period of swing. Other considerations in determining the values of these parameters were the effect of load cells installed within the filars; filar end connections; filar elongation, flexibility, and energy-absorbing properties; system calibration; alignment of fixture and object center of gravity; and the effect ofair damping. During the tests many problems were encountered and solutions determined. When testing was completed, not only did wehave a fair determination of the moments of inertia, but also a good idea of what to avoid on future tests. 1975 28 17.64 0 3714 6362 SAWE1066.pdf 797 SAWE1066 Papers papers/1066/buy SAWE1066
1067 1067. Safety/Reliability and Their Impact on Aerospace Vehicle Weight and Cost The objective of this paper is to familiarize weight engineers with the powerful influence that reliability and safety requirements can have on the weight and cost of aerospace vehicles. Results of typical reliability/safety analyses are used to illustrate the relationships between various levels of potential reliability/safety achievement and the associated program costs. Examples are used to illustrate how the safety requirements are first integrated into the design and how implementation of safety requirements can enhance,or detract from, system reliability. Once the safety requirements have been provided for, system reliability is systematically increased, at increasing cost and weight, until an optimum level is reached that is consistent withminimum total program costs. The manner in which this optimization is achieved is described through the development of typical reliability/weight/cost analyses. It is also pointed out that the detailed implementation of redundancy can involve complexities that transcend the mere addition of backup units. These complexities include the requirement that monitoring devices, with the attendant increases in cost and weight, may also have to be added to the system to attain component redundancy. Emphasis is placed on the necessity for ensuring that reliability and safety analyses are initiated at the start of the design process. It is pointed out that this practice results in the early implementation of reliability/safety design features and in the development of cost and weight statements that reflect the impact of those design features. 1975 10 10 0 3715 6363 SAWE1067.pdf 770 SAWE1067 Papers papers/1067/buy SAWE1067
1068 1068. Will Design-To-Cost Work Over the Long Haul? Design-to-cost has become a popular government procurement discipline, and is considered by proponents as the means bywhich future cost effective weapon systems will be acquired. The subject address relates design-to-cost philosophies with real world problems, and clearly establishes mutual industry/government responsibilities. The analysis reveals significant problem areas which require resolution by both government and industry, if design-to-cost is to become a viable procurement discipline. Problem analysis areas include: * Typical government program cost history * Basic causes of program cost growths * Where the major cost avoidance leverage must be applied * What is required to accurately predict and control cost * Comparisons of design-to-cost applications to a commercial producer * Application of design-to-cost as a life cycle requirement * What is required to ensure positive long term design-to-cost results. 1975 23 14.49 0 3716 6364 SAWE1068.pdf 781 SAWE1068 Papers papers/1068/buy SAWE1068
1069 1069. Engineering Cost Control This paper is offered as a general philosophical approach to Design-to-Cost and shows how the Weight Engineer's area of expertisefits in to the total Engineering Cost Control picture. Several companies are operating Design-to-Cost concepts fortheir commercial programs as well as their military programs. The objectives of Design-to-Cost summarized are as follows: 1. To seek the best balance between performance and cost. 2. Seek capability requirements within a band bounded by minimum acceptable hardware performance and maximum acceptable cost. The performance and cost bounds represent acceptability cutoffs. 3. Initial contract goals to be set in terms of unit production costs. 4. Life cycle cost is the overriding determinant - Designs must not lower unit production costs to meet DTC goals if there is an uneconomical increase in operating and maintenance costs. 5. Allow manufacturers/designers to retain flexibility of configuration by contractually describing mission and performance capabilities required rather than spelling out detailed design specifications. The organization of a Design-to-Cost team is the marrying of several engineering disciplines and cuts throughdepartmental boundaries to obtain the essential team effort.The difference between Engineering Cost Control Group and Design-to-Cost team is explained. Specific references are given to the efforts expended on Bell Helicopter's new commercial Model 222 in the interests of meeting Target Costs and Target Weights. 1975 25 15.75 0 3717 6365 SAWE1069.pdf 771 SAWE1069 Papers papers/1069/buy SAWE1069
1070 1070. The Integrated Team: Key to Implementing Design-To-Cost For many years defense programs have been characterized by almost unlimited funding. Emphasis was placed on performance, and nothing but the best was acceptable. During the past several years however, rising technology costs, an inflationary economy, and competition for federal funds have brought on pressure to reduce defense spending. Design-to-cost now appears to be the answer to the dilemma of cost control in the development of future defense systems. The concept of cost as a design parameter is not totally new. Cost targeting has been used for years by many manufacturers of commercial products. Neither are the techniques used in the design-to-cost new to the mass properties engineer. The traditional approach used for effective weight control is equally applicable to cost control, although cost is a much subtler parameter than weight. Design-to-cost must be implemented properly, or it can fall short as have other DOD cost control procedures. At Convair, we believe that we have carefully designed a management system that provides the framework for successful design-to-cost implementation. The key, we believe, is the integrated team approach. Using an integrated project team organization, Convair product design and system development activities are continuously evaluated against cost requirements with emphasis equal to that placed on technical requirements. Our design-to-cost plan features evolution of the product design to specified cost targets in discretely planned, controlled, and fully traceable steps. This allows us to continuously evaluate progress toward program objectives, technical requirements, and cost goals at predetermined program milestones. These milestones provide a number of performance periods in which our progress can be measured. We complete a design-to-cost cycle within each performance period. Our experiences at Convair in the application of design-to-cost lead us to a number of conclusions and recommendations: Contractual language must reflect carefully delineated requirements and definitions, not only for cost, but also for related performance, reliability, and maintainability requirements. Design-to-cost goals must be established early in the development process. Close coordination between design and manufacturing must begin early and continue throughout the design phase. Vendors and suppliers must also be required to adopt design-to-cost practices. Design-to-cost has demonstrated its effectiveness and value. 1975 15 10 0 3718 6366 SAWE1070.pdf 779 SAWE1070 Papers papers/1070/buy SAWE1070
1071 1071. A Parametric Determination of Transport Aircraft Price What price a given transport airplane will carry is largely a reflection of the manufacturer's assessment of the competitive market into which the new aircraft will be introduced. Thus its design-to-cost target is set in the marketplace. The marketplace is a great normalizer of price, and what differences in price individual customers pay for their airplane depends upon the unique options or equipment they ask to have built into the aircraft. Using the market place prices for transport aircraft, some price relations in terms of weight and thrust have been developed which show normalized prices for discrete families of transport aircraft. 1975 35 22.05 0 3719 6367 SAWE1071.pdf 782 SAWE1071 Papers papers/1071/buy SAWE1071
1072 1072. An Approach to Integrated Cost/Weight Design Methodology The current emphasis on cost analysis and the design-to-cost philosophy within DOD has created an immediate need for analytical methods which can rapidly and accurately estimate the cost of a specific aircraft design. This paper discusses the detail which can and will be required in preliminary design studies to achieve sensitivity to the cost driving design parameters. Some limited experience with new D-T-C methods has revealed that implementation of the system for D-T-C programs will require:(1) A common format for cost and weight data. (2)Manufacturing analysis suitable to preliminary design. (3)Assessment of damage tolerance criteria on cost and weight. (4)Detailed tracking of cost data in advanced technology programs. 1975 6 10 0 3720 6368 SAWE1072.pdf 767 SAWE1072 Papers papers/1072/buy SAWE1072
1073 1073. STAN (R) Developments and Applications This paper will briefly discuss a number of subjects relating to the STAN Integral Weight and Balance System including: 1.Considerations for a Primary IWBS 2.Fairchild 's current involvement with the standard STAN system3. Status report on the C-130 STAN 4. Future developments seen for STAN 1975 16 10.08 0 3721 6369 SAWE1073.pdf 774 SAWE1073 Papers papers/1073/buy SAWE1073
1075 1075. Digital Computer Applications to Weight and Balance Analysis Aviation Technology Incorporated computer products described herein provide a more rapid, positive sequence, precise computation of critical preflight and flight operating data for aircraft than is presently available. Although computation requirements discussed are applicable to all aircraft, the necessity for precise computation is critical for high performance heavy aircraft and in particular, transport/cargo carriers which operate under a multitude of load variations and are subject to many restrictive flight operational parameters. By use of microprogramming and application of modern technology in micro-circuitry the product result is a digital, sequenced controlled and programmed computer dedicated to the solution of aircraft weight and balance and inflight engineering calculations. 1975 6 10 0 3722 6370 SAWE1075.pdf 765 SAWE1075 Papers papers/1075/buy SAWE1075
1079 1079. Aircraft Floor Panel Developments at British Airways (1967-1973) In 1967 testing started on balsa, pvc and aluminum alloy cores with aluminum alloy skins and a cost-effectiveness formula was developed to provide a basis for comparison. A specification for improved aluminum/balsa floors was produced and flight trials began with aluminum/aluminum honeycomb floors. Carbon fibre and later glass fibre came on the scene and a new specification was raised, based on more fundamental criteria. As a result over 500 cfrp/Nomex panels have been fitted in 747 aircraft and about 70 grp/Nomex panels. These are much lighter than earlier types of flooring and more cost-effective. 1975 10 10 0 3723 6371 SAWE1079.pdf 772 SAWE1079 Papers papers/1079/buy SAWE1079
1080 1080. Theoretical Versus Actual Seating Patterns in Wide Body Aircraft Where do people tend to sit in wide bodied aircraft?. Do present day mathematical models used for seating patterns developed for the first generation of jet aircraft apply to double aisle,variable length,multi-service zoned aircraft? Is the sum of individual zone seating variations established by these models adequate for the operational allowance curtailing the certifiedcenter of gravity limits? In order to establish a basis for determining good load-ability for new aircraft design,what is the expected pattern of a total multi-zoned passenger load? Part one of this paper presents an analysis of two sets of data from one Boeing 747 operator. The intent is to attempt to answer or at least locate the problem areas of the above questions. 1975 15 10 0 3724 6372 SAWE1080.pdf 791 SAWE1080 Papers papers/1080/buy SAWE1080
1081 1081. The Weight Engineer in Engineering Flight Test This paper presents a philosophy for the function and responsibilities of the weight engineer's contribution for a new aircraft design, from just prior to rollout and through FAA certification. Many are aware of the workings and functions of the weight engineer in the design and development of a new aircraft. However, it is felt that the weight engineer's role in flight test development and certification demonstration is one with which few are acquainted. 1975 12 10 0 3725 6373 SAWE1081.pdf 769 SAWE1081 Papers papers/1081/buy SAWE1081
1082 1082. Multi-Language Glossary of Weight Engineering Terms and Phrases The scope of this Issue is generally limited to terminology applicable to commercial transport aircraft. The project was prompted as a result of conclusions reached at the Air Systems Workshop of the 32rd Annual SAWE Conference held in London in 1973. Various problems related to international joint ventures were discussed, with the problem of 1anguage differences being considered of first importance. Several types of language aids were proposed, one of which was preparation of a mu1ti-language glossary. The attached preliminary draft presents the current status of the project: The terms have been taken from various weight and balance manuals, load manifests, FAA pub1ications, ATA Specification 100, and released glossaries. All effort in compiling the data has been on a part time basis. Several other SAME members have made valuable contributions, including providing French and German equivalents of the terms. 1975 61 38.43 0 3726 6374 SAWE1082.pdf 794 SAWE1082 Papers papers/1082/buy SAWE1082
1084 1084. Omnibus - Findings of Airline Inflight Passenger Surveys The Omnibus Survey is conducted quarterly during one week in February, May, August and November. The Omnibus data are gathered through United Airlines passengers' completion of self-administered in-flight questionnaires. Distribution of the survey forms is made by the flight attendant to all passengers12 years of age and older. The present program, which dates from May, 1966, represents a replicated random sample of 276 flight segments and generates approximately 10,000 responses per wave. 1975 30 18.90 0 3727 6375 SAWE1084.pdf 766 SAWE1084 Papers papers/1084/buy SAWE1084
1085 1085. Aircraft Concepts for Advanced Short Haul Systems Short haul (less than 500 miles) passenger enplanements represent about 50% of the total domestic enplanements. These can also be distinguished by the annual passenger flow for a given city pair and classified into low, medium and high density markets. NASA studies have investigated various advanced aircraft concepts for short haul that have potentia1 application in these three market areas. A1though advanced operational techniques impact al1 market densities, advanced vehicle design concepts such as RTOL and STOL have the largest impact in the high density markets .Concepts for the medium density market require a careful balancing of performance, technology, and design-to-cost considerations. This paper summarizes the results of recent NASA sponsored high density and medium density short haul air transportation systems studies. Trends in vehicle characteristics and operational requirements will be indicated in addition to economic suitability and impact on the community. 1975 15 10 0 3728 6376 SAWE1085.pdf 789 SAWE1085 Papers papers/1085/buy SAWE1085
1086 1086. Calibration of On-Board Weight and Balance Systems The objective of this paper is to present an overview of the various techniques available for calibrating On-Board Weight and Balance Systems. The techniques, as presented, represent a broad spectrum of weighing approaches, some of which are no longer in common usage but are included for over-all perspective. The major emphasis is on the use of weighing scales, particularly the BLH NEWS System, which uniquely lends itself to the calibration of On-Board Weight and Balance Systems. Since the system was specifically designed to determine weight and center of gravity of aircraft, it very readily lends itself to the intended calibration function. The MEWS system is described in detail to acquaint the reader with its characteristics as well as the best way of using this equipment for its intended function. 1975 6 10 0 3729 6377 SAWE1086.pdf 793 SAWE1086 Papers papers/1086/buy SAWE1086
1087 1087. Load Cells Used to Certify Masses This paper describes a technique for using standard strain gage load cells to certify masses, as defined in a paper by Paul Pontius of the Nat.iona1 Bureau of Standards. Specific data and equipment is described and pictured for a recent verification of 10, 000 lb weights at Edwards Air Force Base, as performed by the Navy Standards Lab., Pomona, California. While the technique is about ten years old, its review at this time is appropriate, since many agencies responsible for such work may not be aware of its existence. It was born during the urgency of the missile crisis, and perhaps did not receive proper publicity, particularly in commercial circles. In view of the current explosive acceptance of electronic weighing in industry, which often must comply with regulations that are at best technically debatable, review of this technique highlights some measurement basics which have fundamental significance for better scale design and performance. These basics are summarized in ten design goal criteria. 1975 25 15.75 0 3730 6378 SAWE1087.pdf 768 SAWE1087 Papers papers/1087/buy SAWE1087
1091 1091. Weight Contribution to Fuel Conservation for Terminal Area Compatible Aircraft The potential weight characteristics of advanced aircraft are reviewed for their possible contribution to reduction of fuel use by future transports. The trades between weight reduction versus increased aerodynamic and operating efficiency are described. Weight reduction through use of advanced technology in items such as structure and airfoils, proper choice of engines, and revised environmental control systems is shown to offer a direct contribution to fuel conservation. Wing plan form optimization results in increased weight with thin, high aspect ratio and reduced sweep wings; however, weight penalties are beneficially countered by a pronounced increase in aerodynamic efficiency. Results of isolated studies of several technical areas applied to an example 200 passenger, 5556 km (3000 nmi) design range transport operated at a long-range cruise Mach number of 0.80 are discussed. Overall, 21.6% reductions in operational empty weight and takeoff gross weight are obtained, as compared to a conventional design that utilizes current technology. The weight penalties incurred by design features to reduce congestion, noise, and emissions in the terminal area are discussed. It is shown that features for reduction of congestion (delay) and emissions also offer fuel reduction potential; however, weight and fuel-use penalties result from noise reduction features. The considerable research and technology effort required to achieve a resulting nominal 25% fuel reduction potential on future aircraft during the latter half of the 1980 decade is outlined. 1975 25 15.75 0 3731 6379 SAWE1091.pdf 786 SAWE1091 Papers papers/1091/buy SAWE1091
1094 1094. A Loadability Comparison of the L-1011 and DC-10-10 The loadability of the -McDonnell Douglas: DC-10-10 and Lockheed L-1011TriStar are compared based on the models operated by Delta Air Lines, One operator's experiences with the two airplanes are presented for comparative purposes to other wide-body's trijet operators, and as feedback information to the manufacturers, design engineers.Both are 250-seat wide-body trijets with similar dimensions and weights. The DC-l0 had a lower, Operational Empty Weight at delivery by 6,000 pounds, but weight growth over a longer period for the DC-10 has reduced this margin. The tail engine location causes some differences in the exterior dimensions, but the cabin sizes are virtua1ly the same. The locations of the forward cargo compartment and under floor galley are reversed on the two airplanes. The L-1011, having the galley behind the cargo compartment has more forward C.G. movement from forward cargo, but it’s empty C.G. starts out farther aft. .The L-1011 has a slightly wider C.G. envelope, and does not require ballasting for operation without payload. The L-1011 carries two more cargo containers than the DC-10, but has more restrictions on cargo container and compartment limits. 1975 14 10 0 3732 6380 SAWE1094.pdf 783 SAWE1094 Papers papers/1094/buy SAWE1094
1095 1095. USAF In-Service Weight and Balance System The objective of this paper is to inform all companies which work with Air Force aircraft how the in-service weight and balance system currently works, so that they will have a better understanding of the Air Force’s desire pertaining to how the technical orders for weight and balance should be made up and how they are to be maintained for field use. This paper helps to keep the Chart Es between different aircraft companies similar so that the main in the filed working on different aircraft will not be as confused, thereby eliminating errors.. Also, the paper shows past mistakes so these errors do not reoccur. It also shows the interrelationship between T.O. 1-1B-40, T.O. 1-1B-50, T.O. -5, MIL-W-25140 and MIL-\5290. This paper presents the Air Force desires pertaining to the technical orders not found in military specifications, and thereby supplements these specifications.

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