SAWE Technical Papers

@inproceedings{3443,

title = {3443. Alternate & Overhead Space Utilization In Long-Range Commercial Aircraft},

author = {Ralph D. Druckman},

url = {https://www.sawe.org/product/paper-3443},

year  = {2008},

date = {2008-05-01},

booktitle = {67th Annual Conference, Seattle, Washington},

pages = {34},

address = {Seattle, Washington},

abstract = {The Overhead Space Utilization (OSU) feature provides operators of Boeing airplanes with a range of options as rest space for flight and cabin crew with minimal impact to passenger cabin floor area (and seat count) while avoiding loss of revenue belly cargo capacity. As use of longer-range passenger airplanes on routes with flight durations requiring rest periods for flight crew and cabin attendants increases over time, the need for providing dedicated rest facilities and space for other main cabin passenger service functions has become much more important. The paper covers the evolution of pre-OSU and OSU concepts and provides insights into impacts of incorporating OSU. It is intended to provide a historical perspective, rather than functioning as a design guide.},

keywords = {10. Weight Engineering - Aircraft Design, 20. Weight Engineering - Specifications},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3446,

title = {3446. Weight Control Responsibility, Authority, & Accountability},

author = {Kenneth LaSalle},

url = {https://www.sawe.org/product/paper-3446},

year  = {2008},

date = {2008-05-01},

booktitle = {67th Annual Conference, Seattle, Washington},

pages = {26},

address = {Seattle, Washington},

abstract = {The roles and responsibilities of the Weight Control Engineer are clearly defined within the Weight Engineering Organization at the Boeing Company. Unfortunately, personnel in other disciplines within the Boeing Company often misunderstand our role - for a variety of reasons. Couple that reality with the trend toward outsourcing design and build responsibilities - whereby partnering companies furnish personnel from various disciplines. Supplying Weight Control Engineers can sometimes present a dilemma if that function does not exist within that company or if the company simply uses the weight engineer as a data recorder. Typically, partnering companies request individuals to perform this role with limited or no understanding. The burden of responsibility now belongs to Boeing to provide the necessary training. Additionally, the new employee has minimal exposure to the weight engineering function. These conditions mandate a philosophy of continual training to address the needs of many incoming personnel to Weight Engineering. This paper focuses on highlighting weight control attributes, addressing responsibilities, command of subject / authoritative effectiveness, and resultant accountability. These principles are intended to establish the solid foundation. Coupled with other SAWE papers pertaining to Weight Control, they will both aid and expedite the individual toward becoming effective in performing weight control.},

keywords = {10. Weight Engineering - Aircraft Design, 28. Weight Reduction - Processes},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3447,

title = {3447. Developmental and Operational Considerations of The Boeing 747 Dreamlifter},

author = {Ryan Kwaterski},

url = {https://www.sawe.org/product/paper-3447},

year  = {2008},

date = {2008-05-01},

booktitle = {67th Annual Conference, Seattle, Washington},

pages = {29},

address = {Seattle, Washington},

abstract = {The 747 Dreamlifter is a modified 747-400B passenger airplane that is simultaneously similar and largely different when compared to airplane it was created from. Large portions of the fuselage structure have been replaced and expanded to allow the Dreamlifter to carry Boeing 787 Dreamliner sections from around the world to Everett, Washington for final assembly. Along with the drastic fuselage modifications, the Dreamlifter has an 18,000 pound aluminum aft pressure bulkhead, a swing tail to allow loading of full size 787 parts and a special main deck cargo restraint system that only accepts unique payload support devices. These devices are referred to as Shipping Mechanical Equipment (SME) and were created solely to carry 787 parts onboard the Dreamlifter. In addition to the unique physical attributes of the airplane and the SMEs, some very special ground support equipment has also been designed for loading and unloading payload along with opening and closing the swing tail. 

Due to the unique aspects of the 747 Dreamlifter, special care and thought was required to develop procedures and manuals that offer operational flexibility and requirements for safe operation. This involved such items as a streamlined loading schedule, item specific loadable regions on the main deck and significant mass properties analysis. 

Development and Operational Considerations of the Boeing 747 Dreamlifter will touch almost every aspect of the Dreamlifter program from developmental and mass properties analysis to operational concerns and the airplane's main mission to deliver full-size 787 components to final assembly.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3450,

title = {3450. Boeing Optistruct Usage: Challenges of Implementation and the Emergence of a New Design Role},

author = {Greg Rucks},

url = {https://www.sawe.org/product/paper-3450},

year  = {2008},

date = {2008-05-01},

booktitle = {67th Annual Conference, Seattle, Washington},

pages = {14},

address = {Seattle, Washington},

abstract = {Since 2004, Boeing has been using Altair's Hypermesh and Optistruct pre- and post- FE processors as a means of reducing airplane weight. 

The process consists of two main optimization methodologies: 1) topology, which determines optimal load paths by iteratively re-orienting material within a given design space to maximize stiffness and 2) size & shape, finalizing the geometry by fine-tuning dimensions via gauge property modification or FEM morphing. 

Unorthodox part shapes and sizing combinations tend to result from these processes on parts ranging from Flight Control Actuators to Wing Primary Structure to Power Distribution Panels and Racks within the Electronics Bay. 

The optimization methods and processes currently in use by Boeing have resulted in average weight savings of 20% on 100+ parts, which usually also exhibit performance improvements with respect to stiffness, stress, and resonant frequency. 

While the design process is technically sound and has provided valuable results, several logistical challenges nevertheless arise during implementation. These challenges are systemic in nature and suggest a fundamental re-thinking of the design team structure and the nature of the interactions among its constituent parts.},

keywords = {10. Weight Engineering - Aircraft Design, 28. Weight Reduction - Processes},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3403,

title = {3403. Topology Optimization on the Example of an Advanced Trainer Aircraft},

author = {Hansjürgen Anton and Herbert Hörnlein},

url = {https://www.sawe.org/product/paper-3403},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {12},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {During the concept and definition phase of an aircraft, it is essential to define a structural concept, which provides the required strength and stiffness constraints of the airframe, subjected to a minimum of weight. The most efficient way of load transfer is a straight and undisturbed load path. However, the design space of the airframe is restricted by the outboard profile, which is defined by aerodynamics and flight mechanics and is also determined by the inboard profile, which is driven by systems installations. Howeve,r there are situations where a major load path cannot be continued, as is ideal. This presentation shows an example of how topology optimization can give one an idea to find an alternative load path. The example is given by a main wing attachment frame, which has the task of carrying the wing bending moment from one wing to the other. However, the air intake duct disturbs the assumed load path. There were some doubts by experienced airframe designers whether this air vehicle concept would work in an acceptable way in terms of mass and strength. The results of the topology optimization unveiled an alternative load path, which is subsequently interpretable by airframe engineers. This presentation also shows how the process goes from a given design to data for manufacturing.},

keywords = {10. Weight Engineering - Aircraft Design, 24. Weight Engineering - System Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3408,

title = {3408. On-Board Weight and Balance Application},

author = {Sylvain Vacher},

url = {https://www.sawe.org/product/paper-3408},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {20},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {Everyday operation requires aircraft operators to have a load control process/system in order to ensure that aircraft weights and associated center of gravity remain within limits. For that purpose, the ground flight preparation usually relies on Departure Control Systems that generate, for each flight, the load and trim sheet for the attention of the captain. For some years now, Electronic Flight Bag solutions have been developed to bring added value to this general process by providing pilots with an additional portable weight and balance application. Using this application, pilots can further improve the current process by saving time-consuming requests for load sheet re computation to the ground. This paper focuses on this added value that an on-board weight and balance application can bring to manage everyday load control. The example of Airbus last generation application (developed for the A380) is used.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3410,

title = {3410. Initial Sizing Optimization of Anisotropic Composite Panels with T-Shape Stiffeners},

author = {J. Enrique Herencia and Paul Weaver and Michael Friswell},

url = {https://www.sawe.org/product/paper-3410},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {31},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {This paper provides an approach to perform initial sizing optimization of anisotropic composite panels with T-shape stiffeners. The method divides the optimization problem into two levels. At the first level, composite optimization is performed using Mathematical Programming (MP), where the skin and the stiffeners are modeled using lamination parameters accounting for their anisotropy. Skin and stiffener laminates are assumed to be symmetric, or mid-plane symmetric laminates with 0, 90, 45, or -45 degree ply angles. The stiffened panel is subjected to a combined loading under strength, buckling, and practical design constraints. Buckling constraints are computed using Closed Form (CF) solutions and energy methods (Rayleigh-Ritz). Conservatism is partially removed in the buckling analysis considering the skin-stiffener flange interaction and decreasing the effective width of the skin. Furthermore, the design and manufacture of the stiffener is embedded within the design variables. At the second level, the actual skin and stiffener lay-ups are obtained using Genetic Algorithms (GAs), accounting for manufacturability and design practices. This two level approach permits the separation of the analysis (strength, buckling, etc), which is performed at the first level, from the laminate stacking sequence combinatorial problem, which is dealt efficiently with GAs at the second level.},

keywords = {10. Weight Engineering - Aircraft Design, 23. Weight Engineering - Structural Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3411,

title = {3411. Design Optimization in Aircraft Component Pre-Design},

author = {Tilo Klemt and Kim Oltmann},

url = {https://www.sawe.org/product/paper-3411},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {11},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {An efficient use of CAE applications in modern aircraft development can lead to shorter development cycles and reduced development costs. This is a sophisticated task for a complex aircraft component with multidisciplinary requirements. In order to get the best possible design, extensive parameter studies are often carried out and the results compared; they may require substantial computations. This situation can often be found in other technical areas and results in the development of a software generation called ?PIDO? (Process Integration and Design Optimization). The traditional CAE development process uses trial and error analysis to find a design that satisfies all of the given requirements. Under normal circumstances, the weight engineer defines the parameters for computing the product attributes. The emerging class of PIDO works, in the opposite direction, by determining the optimal design parameters necessary to meet the target functional performance attributes. This paper is about the primary structure optimization of an aircraft vertical tail. The focus is on the bending-torsion-box variation to find a lightweight solution using a simplified stress model.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3412,

title = {3412. Influence of Changing Aircraft Masses on Flight and Mission Performance},

author = {Wolfgang Längler and Mario Zimmerman},

url = {https://www.sawe.org/product/paper-3412},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {18},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {The influence of changing aircraft masses on different flight and mission performances is to be demonstrated. In order to make the effects clear, all parameters (engine, fuel quantity, external stores, etc.) but mass are kept unchanged. Some fundamentals of flight mechanics are shown and compared to results of computer simulations of several modern fighters.},

keywords = {10. Weight Engineering - Aircraft Design, 26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3415,

title = {3415. Improve Your Sensor Image with Balance},

author = {Ralf Mauersberger and Timo Laudan and Werner Sellner},

url = {https://www.sawe.org/product/paper-3415},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {53},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {During the preliminary design process of a new aircraft program, engineers often rely on approximated design parameter estimations based on existing aircraft databases, proprietary, or purchased experts? knowledge, as well as by means of safety factors. Once violations of targeted performance requirements or design constraints are identified too late in the development process, a number of cost and resource intensive iterations on the system design might be induced. The paper discusses a ?recipe? for weight engineers supporting the mass properties life cycle?s front-end by utilizing design freedom in early design phases and reducing changes in later development phases by a well directed approach considering uncertainties in the weight engineering process. Likewise, we address a new (weight) engineered way of thinking and working within the mass properties life cycle process. To substantiate the approach, the paper introduces a case study from the aerospace domain opening new capabilities in the weight engineering process. The authors postulate a higher quality of decisions as well as a negotiation support for weight engineers within the design process. Moreover, the continuous and systematic consideration of uncertainties enables the creation of an improved ?risk picture?, reduces system uncertainties in a target-oriented manner, and enables an optimization of resources with respect to the exchange of information with other disciplines.},

keywords = {10. Weight Engineering - Aircraft Design, 28. Weight Reduction - Processes},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3418,

title = {3418. Virtual Engineering Models for Aircraft Structure Weight Estimation},

author = {Kim Oltmann},

url = {https://www.sawe.org/product/paper-3418},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {15},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {This paper describes an engineering model to enable a multidisciplinary design team to address a wider range of complex design issues much earlier than is common today. The virtual engineering model is dedicated to simulate arbitrary structural layouts that incorporate the finite element method into preliminary aircraft design. Moreover, it provides a more accurate geometrical representation of the entire aircraft, both outer surfaces and structural topology, early in the design process. This aircraft modeling will enable interdisciplinary teams to involve more structural and manufacturing requirements so that their effect on weight and cost is known much earlier, gathering higher design fidelity. The goal has been to develop modeling methods using the parametric-associative approach that will take into account designer inputs throughout agreed parameter interfaces; and it does not require extensive modeling effort several times. To test the herein presented model in an enterprise environment, different use cases on component and assembly level were conducted while satisfying typical aircraft design requirements from a configuration and a structural point of view. The results further indicate that the virtual engineering model could provide decisive advantage in terms of time required to find an appropriate component design, a reliable common data source distributed to all incorporated disciplines, and design fidelity. It also indicates that the much earlier involvement of virtual engineering models in a conceptual design process provides major interdisciplinary interfaces so that all design information are obviously shared by avoiding risk that might appear when several data transformations have to be executed.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3421,

title = {3421. Structural Sizing or Weight Estimation in Preliminary Aircraft Design},

author = {Joerg Wenzel},

url = {https://www.sawe.org/product/paper-3421},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {11},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {At early stages of aircraft development, accurate weight estimation of primary structure is of great importance. Fast creation of meaningful finite element models is crucial to preliminary design activities in order to assess many configurations and different structural concepts for the aircraft?s airframe. The paper discusses several aspects concerning the development of structural sizing software for this purpose. Legacy software often suffers from being difficult to maintain and extend. The paper presents ideas how to address this problem. The software in development is based on a component-based architecture that strongly reduces unnecessary coupling of independent concepts and makes components reusable in other related software contexts.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3365,

title = {3365. Firefox: Gunship Structural and Material Considerations},

author = {California Polytechnic State University},

url = {https://www.sawe.org/product/paper-3365},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {17},

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

address = {Annapolis, Maryland},

abstract = {In response to the 2005 American Institute of Aeronautics and Astronautics (AIAA) Team Undergraduate Design Competition, Paladin Aerospace presents Firefox, a new generation gunship to replace the AC-130. Modern demands have outgrown the aging cargo-based airframe of the AC-130H/U Spooky gunship. First introduced during the Vietnam War in 1968, the AC-130 has been modified and improved to meet the continuously evolving demands of modern warfare. In recent years, the proliferation of Anti-Aircraft Artillery (AAA) and low-cost Man Portable Air Defense Systems (MANPADS) has created a gap in defensive technology. Nearly 80% of all fixed-wing aircraft lost during Operation Desert Storm were to MANPAD systems. Spooky, with its low-altitude, predictable, circular attack patterns was particularly vulnerable to these radar and IR seeking devices. The request for proposal (RFP) requires an affordable, highly survivable aircraft to provide lethal firepower during a 4 hour loiter. Firefox moves away from the cargo-based configuration of the AC-130 to a conventional fuselage sized around a single 105mm Rheinmetall tank gun and three 40mm autocannons. This paper focuses on the methods used to reinforce the aircraft for survivability with advanced materials and provide adequate structural support to endure the gun forces. The blast overpressure, recoil force, and heat generated by each of the four guns create material and structural issues unique to a gunship aircraft. Maintaining a low weight is desired to minimize acquisition cost to meet the affordability requirement of the RFP. Only essential areas are reinforced with high strength, resilient, but heavier or more costly materials.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3376,

title = {3376. Paragon: Structure and Weight Considerations for an Advanced Gunship},

author = {California Polytechnic State University},

url = {https://www.sawe.org/product/paper-3376},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {31},

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

address = {Annapolis, Maryland},

abstract = {Tip of the Sword Aerospace, of California Polytechnic State University, was presented with the challenge to conceptually design an advanced military gunship. Tip of the Sword Aerospace has responded with Paragon, a highly survivable gunship that has the capability to provide precise and persistent firepower in high threat combat environments. Paragon is in response to the 2004-2005 AIAA Undergraduate Team Design RFP, which calls for an advanced military gunship that can destroy personnel, light armored vehicles, and buildings at low cost. Paragon is an unmanned combat aerial vehicle (UCAV) that employs a conventional configuration with a high wing, H-tail, and tricycle style landing gear. It is equipped with 15,526 pounds of weapons, including two M230 30mm chain guns, 16 HELLFIRE II?s, and 8 GBU-12 Paveway II bombs. Since the Paragon is a UCAV, it can persist in extremely high risk daytime and night-time environments, without risking the lives of a pilot or crew members. This report presents the conceptual approach used to design the Paragon, focusing on the preliminary sizing, weight estimation, and structural layout processes. Initial sizing was primarily driven by the weapons payload requirement of at least 15,000 lbs, a minimum mission radius of 500 n.m., and a four hour time-on-station without refueling. The structural layout was designed to maximize survivability by implementing robust and redundant design features.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3377,

title = {3377. GRYPHON: Considerations of Weight and Structure in the Design of an Advanced Gunship},

author = {California Polytechnic State University},

url = {https://www.sawe.org/product/paper-3377},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {23},

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

address = {Annapolis, Maryland},

abstract = {In response to the 2004/2005 AIAA Undergraduate Team Aircraft Design Competition?s request for proposal (RFP) for an Advanced Gunship, Fallen Angel Aerospace is pleased to present Gryphon. Gryphon is both highly survivable against MANPADS and AAA and capable of affordable, precise, and persistent firepower. Dorsal mounted engines shield Gryphon?s exhaust plume effectively reducing IR signature and increasing survivability against MANPAD threats. Gryphon features an H-tail for redundant flight controls as well as redundant systems for increased survivability. The primary weapons featured on Gryphon are the GAU-13 for rapid area suppression and the Bushmaster II for pinpoint attacks. These primary weapons are turret mounted to provide flexible and unpredictable attack patterns. Gryphon?s arsenal includes a side mounted howitzer for persistent and flexible heavy firepower. To provide greater standoff and destructive potentiality, Gryphon also features Hellfire missiles and JDAM bombs. The combat mission profile for Gryphon consists of a 500 n.mi. ingress, followed by a four hour loiter and attack period, and a 500 n.mi. egress. Gryphon is a versatile aircraft that effectively fulfills the close air support, airinterdiction and armed reconnaissance roles. Preliminary capability analyses show that three Gryphon aircraft in the close air support role are capable of responding to a situation anywhere in Iraq within 15 minutes. This same task currently requires approximately eight AC-130?s.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3378,

title = {3378. LEBOWSKI: Considerations of Weight and Structure in the Design of an Advanced Gunship},

author = {California Polytechnic State University},

url = {https://www.sawe.org/product/paper-3378},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {23},

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

address = {Annapolis, Maryland},

abstract = {In response to the AIAA Undergraduate Team Aircraft Design Competition?s request for proposal (RFP) for an Advanced Gunship, Mad Hatter Aerospace proudly presents Lebowski. This Unmanned Combat Aerial Vehicle (UCAV) is a remotely?piloted aircraft designed to maximize mission effectiveness while simultaneously minimizing not only mission cost, but also the overall price of the aircraft. It is armed with a complement of guns and droppable ordnance that optimize the precision, persistence, and affordability of the aircraft. The weapons onboard are: two M230 30mm guns, a Bofors L70 40mm Cannon, two GBU-29 Joint Direct Attack Munitions, and four GBU-39 Small Diameter Bombs. Lebowski is equipped with survivability features that have been optimized to meet specific RFP requirements while minimizing weight and maximizing performance. It can cruise at over 400 knots at 30,000 feet and loiter over the target area for four hours at 20,000 feet. The airfoil selection and wing layout are optimized for the RFP mission and feature a modified 6-series airfoil and a slightly blended wing body. Given the RFP requirements for minimum cost and a 400 knot initial cruise at 30,000 feet, a PW 6124 engine is featured on the Lebowski and is sized by taking conservative estimations of future engine technology advances. The structure of the gunship was designed with versatility, survivability, and cost in mind. Lebowski effectively and efficiently fills the niche between the aging AC-130 airframe and the A-10 attack aircraft.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3322,

title = {3322. Weight and Balance Considerations for Flight Test Aircraft On},

author = {Darrin McCloud},

url = {https://www.sawe.org/product/paper-3322},

year  = {2004},

date = {2004-05-01},

booktitle = {63rd Annual Conference, Newport, California},

pages = {24},

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

address = {Newport, California},

abstract = {Weight and balance concerns are critically important during the flight testing stage of any aircraft. Many problems encountered during flight testing can be traced back to design requirements concerning aircraft mass properties and weighing. Due to the challenges associated with preliminary aircraft design schedules and practices, many of these requirements are overlooked. There are many unique concerns and requirements that need to be addressed before the test aircraft configuration is finalized. These issues range from weighing difficulties associated with unique test aircraft configurations to the inability to fly required flight profiles. One common mistake involves trying to install too much test equipment on one aircraft, which can result in the previously stated problems. If the test aircraft has sufficiently different mass properties from the production aircraft, it is also possible that the data collected is not truly representative of the production aircraft. Another difficulty concerns inaccurate mass properties, which can lead to issues ranging from invalid data to the possibility of the loss of aircraft and life. Not recognizing these problems and test requirements at an early stage of the program can lead to costly and time consuming fixes at a later date. This paper will concentrate mainly on topics concerning mass properties and aircraft weighing that may be encountered while flight testing small and medium sized 14 CFR (previously FAR) Part 25 aircraft.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3310,

title = {3310. SumMassProps - An Excel VBA Solution for Summing Mass Properties},

author = {Robert L. Zimmerman},

url = {https://www.sawe.org/product/paper-3310},

year  = {2003},

date = {2003-05-01},

booktitle = {62nd Annual Conference, New Haven, Connecticut},

pages = {45},

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

address = {New Haven, Connecticut},

abstract = {Microsoft Excel is a general-purpose spreadsheet program that lends itself to mass properties calculations. There have been many papers written and presented to the SAWE showing differing techniques to use in determining assembly and vehicle mass properties. The problem with these techniques is that they require a portion of the spreadsheet to be used for storage of intermediate results and the equations used become complex and confusing using Excel?s native symbology. This paper introduces a comprehensive solution set for mass property summation using the built-in Visual Basic for Applications macro language extant in Excel. The solution set, ?SumMassProps.xla,? is embedded in an Excel Add-in. SumMassProps is comprised of three increasingly comprehensive custom functions: CCOG, a function to compute Center of Gravity; CMPROP, a function to compute the complete 10 by X mass property tensor; and CMUP, a function that extends CMPROP by also computing the combined independent uncertainty properties of all ten mass property terms in the mass property tensor. The Add-in also includes facilities to aid in setting up and using the functions in a spreadsheet. By using the Add-in paradigm, the solution set becomes available for use in any spreadsheet that is on the user?s computer. By using SumMassProps, the mass property engineer is freed from spending time debugging spreadsheets and re-inventing the wheel to determine a composite body?s mass properties. This solution set ensures that the proper equations are used and implemented in a consistent manner and speeds up production of reports and ?what-if? scenarios.},

note = {L. R. 'Mike' Hackney Award},

keywords = {10. Weight Engineering - Aircraft Design, Mike Hackney Best Paper Award},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3317,

title = {3317. Weights and Materials Considerations in the Design of an Ultra Heavy Lift Aircraft},

author = {California Polytechnic State University},

url = {https://www.sawe.org/product/paper-3317},

year  = {2003},

date = {2003-05-01},

booktitle = {62nd Annual Conference, New Haven, Connecticut},

pages = {15},

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

address = {New Haven, Connecticut},

abstract = {Abrams Haulers Incorporated (AHI) presents the AHI-10, an Ultra Heavy Lift Aircraft (UHLA) designed in response to the 2002-2003 AIAA Undergraduate Team Aircraft Design Competition. The AHI-10 fulfills the military?s need to transport massive amounts of equipment in a short period of time, allowing them to deploy entire army battalions within days, satisfying the Rapid Global Mobility Requirements of Joint Vision 2020. The 2002-2003 AIAA request for proposal (RFP) requires designing an aircraft capable of transporting a payload of 1.2 million pounds. Other payload requirements include ten M1A2 Abram tanks, 60 463L pallets, 300 medical litters, as well as 1000 paratroops. The performance requirements include an unrefueled range of 5000 nautical miles at 500 knots at a cruise altitude of 25,000 feet. The aircraft is also required to take off and land in a distance less than 9,000 feet. The vast amount of cargo requirements along with the strict performance requirements set by the RFP requires in-depth analysis of structures and mass properties. The mass properties analysis plays an important role in the aircraft?s design, due to the necessity of reducing aircraft weight in order to achieve the maximum performance necessary to satisfy the RFP requirements. After thorough design analysis, the aircraft has a length of 311 feet and a wingspan of 300 feet, incorporating an all-surface lifting configuration. The AHI-10 uses eight GE 90-115B power plants producing a takeoff thrust of 128,000 pounds force per engine.},

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

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3318,

title = {3318. Weight Study of the Gemini : An Ultra-Heavy Lift Aircraft},

author = {California Polytechnic State University},

url = {https://www.sawe.org/product/paper-3318},

year  = {2003},

date = {2003-05-01},

booktitle = {62nd Annual Conference, New Haven, Connecticut},

pages = {26},

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

address = {New Haven, Connecticut},

abstract = {Vesper Design Concepts presents Gemini, an Ultra-Heavy Lift Aircraft in response to the 2002-2003 AIAA Team Undergraduate Aircraft Design Competition. This aircraft is required to carry ten M1A2 Abrams tanks over an unrefueled range of 5,000 n. mi. at 500 kts at an altitude of 25,000 ft. or more. As a conventional aircraft would require a wingspan in excess of 400 ft., Gemini utilizes an unconventional c?wing configuration to limit its span to 300 ft. Weight analysis of an aircraft of such unconventional size and configuration has required/resulted in some interesting weight optimization studies. Empirical methods were the main form of analysis used in creating an optimized weight buildup. Analytical methods were only used to contrast with the empirical ones. Initially, very simple methods based on historical trends and basic parameters were used. These led into more complicated empirical relationships focusing on specific aircraft weight groups. Three different methodologies taken from aircraft design texts, were used to define and optimize the Gemini. These methods, along with known aerodynamic quantities, allowed the wing and canard to be optimized for cruise. The placement of different weight groups on the aircraft allowed construction of its pitching moment equation. This in turn allowed the canard to be optimized for trimming the aircraft during takeoff. The landing gear weight was examined in more detail, as it had to be built to take some unusual conditions, like the 15-feet-per-second vertical descent rate. The structural weight was also examined in more detail, as the empirical estimations most likely did not account for a floor loading as high as Gemini?s.},

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

pubstate = {published},

tppubtype = {inproceedings}

}