SAWE Technical Papers

@inproceedings{3840,

title = {3840. The Learjet 85: Historical Evolution, Critical Challenges and Lessons from a Misguided Program},

author = {Darrin McCloud},

url = {https://www.sawe.org/product/3840-the-learjet85-historical-evolution-critical-challenges-and-lessons-from-a-misguided-program/},

year  = {2026},

date = {2026-05-21},

urldate = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {The story of the Learjet 85 (LJ85) starts with the Learjet 60 (LJ60). In 2004 the LJ60 was the largest Learjet in production, however it suffered from many problems that were causing it to lose valuable market share. Foremost was that the LJ60 used the same basic wing and main landing gear (MLG) design that traced its lineage all the way back to the Learjet 23 in the early 1960’s. Based off the original Swiss fighter jet wing design, this design was thin, very strong, high speed optimized and originally came equipped with tip tanks for additional fuel storage. It was now being used on a plane that weighed twice as much, had winglets instead of tip tanks and was limited to the same small size wheels. The following issues were the result:

1. Poor landing performance due to high landing speeds and undersized brakes

2. Large fuselage tank required due to small wing fuel volume

3. CG issues due to short MAC length and large fuel moment change



By the Summer of 2005, Learjet was ready for an internal launch of our new project. It was a design that would have instantly been recognized as a Learjet in both the performance and the external lines. Heritage aluminum structure and classic manual flight control systems would be used in line with all previous models. Newer LJ45 style systems and wing aerodynamics would be combined with a lengthened LJ60 fuselage to create a low-cost successor to the long in the tooth LJ60. It was called various official program names over the next year, but many of the employees liked to call it the Learjet 65.},

keywords = {Aircraft - Commercial},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3841,

title = {3841. Recommended Practice (RP) Functional Sub-codes: Simplified Part Categories for Better Early Program Weight Estimation and Enabling AI Analysis},

author = {Roman Aman},

url = {https://www.sawe.org/product/3841-recommended-practice-functional-sub-codes-simplified-part-categories-for-better-early-program-weight-estimation-and-enabling-ai-analysis/},

year  = {2026},

date = {2026-05-21},

urldate = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {In today's world Mass Properties engineers are expected to do more with less. This paper walks through a breakthrough method of using simplified part categories (Recommended Practice Sub-codes) to quickly summarize data, check for errors, and generate new parametric relationships. The method, is simple, proven, and perhaps the most game changing addition to Recommended Practice (RP) in decades. As a result of using this method any Mass Properties engineer will be able to formulate important parametric weight estimation relationships for future programs and by using those relationships estimate missing components at a detailed part level.



Just as recommended practices use Page, Column, Row, codes to define the function of parts. Within that function there may be dozens of different kinds of parts that leave people unable to recreate details during preliminary design. Likewise, RP functional codes take time and experience to assign at a detailed level and must be re-coded each time the design changes. Sub-codes or part categories are simpler and stay the same no matter what RP function and can be almost entirely coded automatically saving time. They are intended to be used with RP functional codes.



The RP coding tells us what system or function a part has as part of the overall vehicle system for example Hydraulics. The sub-codes go one more level lower and define what that part is – tube, fitting, bracket, P-clamp, or fluid. With this data we can estimate parts at a lower level and better estimate missing parts during preliminary design.



Finally, due to the automated nature of sub-codes aka part categories, we can fuel future AI efforts by forming thousands of additional weight estimating relationships as compared to RP functional coding alone. The simplicity of these categories makes them far more likely to align one design to another. With simplicity and automation also comes the ability to error check weight estimates faster.},

keywords = {Aircraft},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3842,

title = {3842. Modernizing SumMassProps},

author = {Robert Zimmerman},

url = {https://www.sawe.org/product/3842-modernizing-summassprops/},

year  = {2026},

date = {2026-05-21},

urldate = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {In 2003 I created the initial version of SumMassProps, an Excel Add-In that created a macro-based Excel solution for correctly summing the 10 basic mass properties (Mass, 3-axis Centers of Gravity, 3-axis Moments of Inertia, and 3-axis Products of Inertia). This was released as SAWE Paper 3310. This solution had a bare-bones Graphical User Interface (GUI) that only created the necessary header lines required to run the Add-In, all the “guts” of the solution were accessed using Excel’s built-in Paste Function) to access each of the Add-In’s summing functions.



This was not ideal. Although the original 2003 version of SumMassProps did ensure that the consistent equations were used to sum mass properties, in 2012 a major update was issued as

SAWE paper 3574. This update included a full GUI utilizing menus to access the various functions, as well as adding additional functionality to the Add-In. This version also included corrections to the summing of mass properties uncertainties as covered in SAWE paper 3360 “Are You Sure?”. In 2009 Microsoft created a different way to access functions and macros, calling this new method the Ribbon. Later, access to functions and macros using menus was discontinued within Visual Basic for Applications, the language used to create the SumMassProps Add-In, and

the Add-In would fail to load. This forced either a return to the 2003 method or a re-write of the program to encompass the new Ribbon paradigm versus a menu driven paradigm.



This paper describes the necessary steps to implement a Ribbon-based Add-In, and will also be a release for SumMassProps Version 10 (2026) that utilizes a Ribbon-based paradigm, which necessitates a re-write of the Tutorial and the User Guide to walk the user through the Add-In.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3843,

title = {3843. Digital Exposure of Mass Properties Data},

author = {Nick Thies},

url = {https://www.sawe.org/product/3843-digital-exposure-of-mass-properties-data/},

year  = {2026},

date = {2026-05-21},

urldate = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Providing mass properties data for the consumption of others is, and may always be, a deliberate act. Whether that data takes the form of a periodic data deliverable, like a status report, or a specific

response to a customer question, Mass Properties Engineers must frequently mine and manipulate data to satisfy the needs of others. The data maintained within any mass properties database has a breadth that far exceeds simple numerical values of weight, center of gravity, and inertia. Most often, a database includes a labyrinth of codes and descriptors necessary to sort, parse, and aggregate those core numerical values in a meaningful way. Few people other than the Mass Properties Engineers tasked with maintaining that data have any real success gathering/assessing the data sufficiently well to satisfy specific data requests. As a result, both Mass Properties Engineers and customers persist in a request/provide, request/provide paradigm. Even when considering periodic data deliverables, this cycle is preserved (with an implied request). Establishing methods by which mass properties data can be openly exposed, in a meaningful way, serves to break down this cycle. Many data requests need not be asked again; the data is always available without request. In some cases, periodic data deliverables are challenged, relegated to historical practices, as they are replaced by real-time or near-real-time data. However, realizing such a paradigm-breaking scenario cannot occur without one thing – a deliberate act to do so. This paper presents fundamental changes which enable digital exposure of mass properties data.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3844,

title = {3844. Unintentional Lateral Imbalance Calculation Methodology for Freighter Aircrafts},

author = {Alejandro Fiestras Corcho},

url = {https://www.sawe.org/product/3844-unintentional-lateral-imbalance-calculation-methodology-for-freighter-aircrafts/},

year  = {2026},

date = {2026-05-21},

urldate = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {In heavy-cargo operations, lateral imbalance is a silent threat to flight efficiency. This methodology introduces a proactive simulation framework designed to identify and prevent "non-viable" loading states before the process even begins. It specifically targets the complexity of empty positions, leading to scenarios where asymmetrical cargo locking or mechanical failures prevent balanced loading across the aircraft’s roll axis.



The method, based on a published patent (ref [1]), allows the user to explore specific cargo layouts with stochastic weight distributions. The system executes multiple simulations to project the accumulated lateral moment. This allows the method to assess flight feasibility against given limit conditions, even when exact individual weights are unknown a priori.



Key Technical Advantages:



- Preventive Risk Mitigation: It establishes a clear "Viable/Non-Viable" binary before any physical loading occurs, preventing potentially inconvenient roll-axis

moments.

- Stochastic Modeling: Uses input probability functions to account for weight uncertainty, ensuring efficiency in real-world conditions where load data is often

uncertain.

- Asymmetrical Failure Analysis: Specifically models the impact of "locked" or disabled cargo locations, turning a complex mechanical limitation into a predictable data point.



This method transforms aircraft loading from a manual estimation task into a data-driven protocol, ensuring that no freighter departs with a lateral moment profile that is not convenient for the airline.},

keywords = {Aircraft - Commercial},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3845,

title = {3845. The Earned Value Evolution of the Plan to Perform},

author = {Patrick Brown},

url = {https://www.sawe.org/product/3845-the-earned-value-evolution-of-the-plan-to-perform/},

year  = {2026},

date = {2026-05-19},

urldate = {2026-05-19},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Earned Value Management (EVM) is a widely recognized project management technique for objectively measuring project performance by integrating scope, schedule, and cost. The Mass Properties Plan to Perform (PtP) is used in the total product lifecycle Program Development phase for managing and communicating status empty, target, and not-to-exceed (NTE) weights. This paper explores the possibility of superimposing the EVM techniques onto the PtP process. And by leveraging the EVM vernacular, the author hopes to achieve the following results:

- PtP with ‘earned weights’ (status and NTE as compared to target weights)

- Improved Program, Chief Engineer, and Integrated Team communication (performance indices and variance analysis)

- Wider understanding within non-technical disciplines e.g. Business Management team, Global Supply Chain, etc. (conceptual commonality with established EVM and relationships)



While the concepts presented in the paper are practical, and loosely follow both EVM and PtP methods, the application and examples provided are hypothetical.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3846,

title = {3846. Vendor Guarantee Weights in Product Development},

author = {Doug Fisher},

url = {https://www.sawe.org/product/3846-vendor-guarantee-weights-in-product-development/},

year  = {2026},

date = {2026-05-19},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Aircraft OEMs outsource significant design and build scope to vendors/suppliers. A Guarantee weight (often termed a Guaranteed-Not-to-Exceed weight) is the maximum allowable delivered weight of a supplier’s item. This paper outlines key considerations for establishing Guarantee weight agreements between design/manufacturing suppliers and aircraft OEMs in the civil aviation industry. Contractually binding Guarantee weights are critical to meeting aircraft performance and safety goals. Because suppliers face penalties for non-compliance, Guarantee weights must be realistically achievable within program cost and schedule constraints. Guarantees are often set early in development, before the design is stable. Early unknowns create weight risk that must be accounted for (via management reserve, weight-growth allowance, or other countermeasures) to reach an agreement acceptable to both parties.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3851,

title = {3851. Roll and Horizontal Axis Moment of Inertia (MOI) Measurements using a Gravity Pendulum},

author = {James Blair},

url = {https://www.sawe.org/product/3851-roll-and-horizontal-axis-moment-of-inertia-moi-measurements-using-a-gravity-pendulum/},

year  = {2026},

date = {2026-05-19},

urldate = {2026-05-19},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Customers with long cylindrical parts have had difficulty measuring the inertia about the roll axis on systems that require the part to be mounted vertical in order to conduct the measurement. This has led to issues with the requirement of a variety of fixtures and risky handling of parts in order to orient the part. Raptor Scientific has developed a measurement system that measures inertia about the roll axis in a horizontal manner using an air bearing fixture and universal rings to measure the time period, and when combined with center of gravity measurements from a KSR instrument and mass measurements, determines the inertia about this axis. This paper examines the goals of the end user, the process used in designing the fixture, final results and accuracy requirements / what is achievable, and lessons learned along the way for the design and build of the final deliverable instrument.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3854,

title = {3854. The Impact of Changing Test Weight Vertical Center of Gravity on a Shipboard Inclining Experiment},

author = {Alan Bryden and Rob Dvorak },

url = {https://www.sawe.org/product/3854-the-impact-of-changing-test-weight-vertical-center-of-gravity-on-a-shipboard-inclining-experiment/},

year  = {2026},

date = {2026-05-19},

urldate = {2026-05-19},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Changes to the vertical position of the test weights during the course of an inclining experiment affects the experiment results. In most cases, weight movements are perpendicular to the ship’s centerline plane and do not change in height. However, this may not be practical, or it may be more economical to raise or lower the elevation of the weights during the inclining experiment. It is up to the naval architect to determine the magnitude of this effect and whether it should be included in the calculations. This paper assists the naval architect in consideration of alternative means of performing an inclining experiment without sacrificing accuracy. This paper takes a geometric approach to the derivation of the GM equation and factors in the adjustment due to vertical weight movements. “Small angle” assumptions for the GM calculation remain and the effect of changes to those assumptions are not addressed in this paper. The primary drivers of error when moving the weights vertically are the magnitude of the angle of inclination and the ratio of the distances of the vertical movement with respect to the horizontal movement. This paper presents a correction factor tool for naval architects to determine the magnitude of the effect and how to include the effect in the results if necessary.},

keywords = {Marine},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3855,

title = {3855. Double-Shell and Sandwich Fuselages for Future Aircraft},

author = {Hans-Peter Dahm},

url = {https://www.sawe.org/product/3855-double-shell-and-sandwich-fuselages-for-future-aircraft/},

year  = {2026},

date = {2026-05-21},

urldate = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {There are several fuselage concepts which show alternatives in comparison to the classical cylindrical fuselage concept. Double-shell fuselages include classic double-bubble cabins, double-D variants, and multi-shell arrangements in which one or more near-cylindrical pressure lobes are enclosed by an outer aerodynamic shell. This paper restructures the topic and describes basic structural-mechanical behavior of double-shell sandwich fuselages. The objective is to determine when shell duplication in a sandwich creates a real mass benefit and when it redistributes mass among pressure skins, outer shells, webs, floors, and reinforcement details. A literature review is combined with a mechanics-based preliminary sizing method and a worked A220-like derived sample calculation. The paper then develops a separate aircraft-level estimate for a concentric circular double-shell sandwich concept manufactured as pre-equipped major shell modules. The approach combines a bottom-up structural mass build-up for the circular double-shell fuselage concept with a top-down aircraft-level fuselage-group allocation for the broader savings assessment. These two approaches serve different purposes and therefore produce different mass values. A future aircraft must integrate cryogenic hydrogen tanks, insulation, battery systems, cable runs, thermal management hardware, and larger secondary systems volumes than conventional kerosene aircraft. The architecture-only estimate yields a net installed mass saving of about 1.28 t. When a conservative transition from a public A220-like mixed-material fuselage baseline to a full thermoplastic-resin CFRP fuselage is added, with overlap correction to avoid double counting, the holistic aircraft-level rises to about 2.01 t. On a 39.0 t class level operating-empty-weight baseline this corresponds to about 5.16% of OEW, while remaining a concept-level result rather than a validated OEM design value. Public thermoplastic fuselage demonstrator results are treated conservatively as weight-positive but recurring-cost neutral relative to a metallic barrel, so the recurring production benefit remains dominated by modular preinstallation and reduced detail count at about €0.30 million per aircraft.},

keywords = {Aircraft - Commercial},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3856,

title = {3856. Weight Management of Ground Vehicles: A Mass Properties Control Framework for Road, Off-Road, and Special-Purpose Platforms},

author = {Hans-Peter Dahm},

url = {https://www.sawe.org/product/3856-weight-management-of-ground-vehicles-a-mass-properties-control-framework-for-road-off-road-and-special-purpose-platforms/},

year  = {2026},

date = {2026-05-21},

booktitle = {85th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Ground vehicles are frequently managed by curb mass, gross vehicle mass, or payload, but those scalar measures do not adequately control the engineering risk created by the distribution and maturity of mass. This paper presents a practical mass properties engineering framework for weight management of ground vehicles, including passenger cars, trucks, buses, motorcycles, electric bicycles, construction machines, special-purpose vehicles, and tracked platforms. The objective is to convert weight management from late-stage reporting into a closed-loop control process that supports architecture decisions, homologation, stability, braking, steering, energy use, payload, and lifecycle configuration control. The proposed approach combines top-down allocation of mass, center of gravity, axle loads, wheel loads, inertias, and reserves with bottom-up roll-ups from computer-aided design, bills of material, supplier data, and physical measurement. It distinguishes current mass from forecast mass, mass growth allowance from uncertainty, and certification limits from engineering margins. The method uses a defined mass state, a vehicle-family-specific risk register, a gate-based verification plan, and an escalation path whenever not-to-exceed values, axle reactions, center-of-gravity limits, or stability constraints are threatened. The central finding is that the best ground-vehicle program is not necessarily the lightest program; it is the program whose mass properties are controlled at the right level of maturity for each decision. For passenger cars and performance vehicles, the dominant risks are variant accretion, battery placement, unsprung mass, and inertia drift. For trucks and buses, payload, axle-load reserve, bodybuilder integration, roof-mounted systems, and rollover sensitivity dominate. For two-wheel vehicles, rider, battery, and luggage locations must be treated as part of the system. For construction and tracked vehicles, implement position, ballast, soil pressure, and transport configuration require explicit mass states. The paper concludes with an implementation checklist, for example status record, and peer-review checklist intended for adaptation to specific ground-vehicle programs. Keywords: mass properties engineering; weight management; ground vehicles; center of gravity; axle loads; moments of inertia; mass growth; uncertainty; vehicle development; verification.},

keywords = {Ground Vehicles},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3815,

title = {3815. Defending Mass Properties},

author = {Robert Zimmerman},

url = {https://www.sawe.org/product/3815-defending-mass-properties/},

year  = {2025},

date = {2025-05-20},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {The mass properties profession as viewed by outsiders is a simple job, even not seen as true

engineering, a glorified accounting job. As seen from the inside, we who endeavor to perform

mass properties as a career know that mass properties is simple is not the case. This

dichotomy of views hinders our ability to perform our function, lowers our perceived value, and

even threatens our very existence on programs. This problem stems from bias and ignorance from

those who aren’t intimately familiar with our capabilities and the perception that two equations are

the foundation of mass properties.

The first equation is:

This equation has two consequences, first it equates mass and weight, and secondly the equation

cements the mindset that the role of the mass properties practitioner is that of a weight accountant.

The second equation is:

or simply put weight equals density times volume. Although true, this is only applicable in limited

situations that a mass properties engineer encounters, yet this limited aspect is not thought about

by most people, even in engineering. The equation applies to most structural elements, such as a

strut or a beam, but is inapplicable when an item is made of multiple components such as an

electronic box. Moreover, these equations completely ignore other aspects of mass properties

engineering such as determination of Centers of Gravity and Inertia, as well as reporting,

controlling mass properties, and verification activities.

This paper will use the author’s own experience with interactions with personnel he has

encountered in his career and present ways to counter the “Mass Properties is Simple” mindset

to make believers out of mass properties skeptics.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3816,

title = {3816. Empowering Mass Properties Engineers with Artificial Intelligence: Transforming Estimation, Analysis and Optimization},

author = {William Boze},

url = {https://www.sawe.org/product/3816-empowering-mpe-with-ai/},

year  = {2025},

date = {2025-05-22},

urldate = {2025-05-22},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {The integration of Artificial Intelligence (AI) into engineering disciplines is revolutionizing traditional workflows, enabling unprecedented efficiencies and innovations. For mass properties engineers, AI offers transformative capabilities in estimation, analysis, data integration, and design optimization, addressing challenges inherent in vehicle design and development. This paper explores the practical applications of AI in mass properties engineering, highlighting some key areas of opportunity. Additionally, the paper in the appendix provides a comprehensive, structured reference collection tailored for engineers seeking to harness AI’s potential, bridging the gap between theory and practice.

By equipping engineers with AI knowledge and tools, this work aims to redefine the boundaries of what is possible in mass properties engineering and inspire a new wave of innovation in mass properties prediction and control.},

keywords = {SAWE Inc.},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3817,

title = {3817. Mass Property Data Checking for Modular Construction},

author = {Robert J. Hundl and Jeff Robertson},

url = {https://www.sawe.org/product/3817-mass-property-data-checking-for-modular-construction/},

year  = {2025},

date = {2025-05-20},

urldate = {2025-05-20},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {In the Energy and Chemicals Construction Industry, many projects utilize modular construction, which necessitates transporting modules from the fabrication yard to the project site. This often involves a combination of ocean and land transportation and may require lifting the modules on or off vessels or into place at the site. Ensuring the safe transport and lifting of these modules is critical, with weight and center of gravity being key factors. Despite the accuracy of 3D models, detailed checks of attributes are essential to verify calculations for weight and center of gravity. Large projects, with over 100 modules, can generate more than a million rows of data that need to be checked. Additionally, many items are not modeled, requiring manual estimates that also need verification. Automating this checking process is crucial to allow engineers to focus on critical issues rather than being overwhelmed by data. This paper describes several methods developed to improve data checking and provide more accurate estimates.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3821,

title = {3821. Agile Weight Maturity},

author = {Roman Aman and Melissa Gray},

url = {https://www.sawe.org/product/3821-agile-weight-maturity/},

year  = {2025},

date = {2025-05-20},

urldate = {2025-05-20},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Aircraft developmental weight growth is difficult to accurately predict through the entirety of the design process. This can be attributed in part to the difficulty in quantifying the overall maturity of the aircraft design. Aircraft structures and subsystems are often maturing at different rates, but the expected weight growth typically remains the same within each design phase and is simply reduced as time passes. Time based developmental weight growth does not take into account the varying maturity of individual systems, nor does it account for low or high use of off-the-shelf items. This will vary for every aircraft design. The rate of weight growth typically declines further into the design process as the overall design matures, but understanding weight maturity’s relationship to weight growth can allow the mass properties engineer to better project expected weight growth. Weight maturity can be simplified into five basic categories: “Actual, Calculated, Detailed Design, Preliminary Design, and Initial Estimate”. Maturity categories can be assigned to individual components in a system to help define the combined maturity of that system. Combining the different system maturities will result in a single quantifiable maturity of the whole aircraft. This methodology is directly tied to individual part maturity; therefore, overall vehicle maturity is incrementally updated (monthly/weekly) throughout the design process as even small changes in maturity occur. The result of this methodology is accurate quantification of aircraft maturity and a data driven estimate of retired remaining developmental weight growth.},

keywords = {Aircraft},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3822,

title = {3822. Enabling Digital Transformation in Weights Management: A Unified Data Model for Industry-wide Integration},

author = {Mark Beyer},

url = {https://www.sawe.org/product/3822-enabling-digital-transformation/},

year  = {2025},

date = {2025-05-22},

urldate = {2025-05-22},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {The increasing complexity of Weights Management across aerospace and related industries underscores the need for a unified and standardized approach to data modeling and nomenclature. This paper presents a comprehensive unified data model designed to address the unique challenges of weights management, establishing a robust foundation for digital transformation. By standardizing data definitions, harmonizing nomenclature, and implementing consistent validation processes, the model ensures seamless interoperability across systems and industries.

This forward-looking approach moves beyond conventional practices to embrace advanced tools and methodologies that enhance data integrity and streamline downstream processes. With applicability spanning aerospace, automotive, shipbuilding, and beyond, the proposed model serves as a blueprint for fostering collaboration and alignment among industry stakeholders.

The paper also highlights opportunities for the SAWE community to engage in partnerships that refine and expand this unified approach, creating a shared vision for the future of weights management. Ultimately, the unified data model serves as a cornerstone for driving industry-wide transformation, enabling innovative solutions that improve efficiency, reliability, and integration throughout the weights management lifecycle.},

keywords = {Cross Industry},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3823,

title = {3823. Agile RIO Weights Management Best Practices for Vehicle Development},

author = {Mark Beyer},

url = {https://www.sawe.org/product/3823-agile-rio-weights-management/},

year  = {2025},

date = {2025-05-20},

urldate = {2025-05-20},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Effective Risk, Issue, and Opportunity (RIO) management is vital to the success of product development teams, particularly in weights management, where decisions significantly influence vehicle and program performance. This paper presents a structured approach to standardizing RIO management processes, offering best practices and actionable templates to support integrated product development teams throughout the vehicle maturation lifecycle.

The proposed methodology focuses on not only identifying, assessing, and mitigating risks and issues but also capturing and exploiting opportunities. Central to this approach is the integration of forecasting tools and processes that provide enhanced visibility into program performance. By enabling Agile decision-making, these practices empower teams to anticipate challenges, adapt quickly to evolving conditions, and align with broader program objectives.

With standardized RIO templates and improved forecasting capabilities, weights management teams can enhance collaboration, streamline communication, and optimize resource allocation. This paper underscores the critical role of proactive RIO management in driving program success, ensuring that teams are equipped to navigate complex challenges and seize opportunities for innovation while maintaining program agility and performance excellence.},

keywords = {Cross Industry},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3825,

title = {3825. A Study of a Moving Mass Coaxial Monocopter},

author = {An Nguyen and Samuel Maimako and Mostafa Hassanalian},

url = {https://www.sawe.org/product/3825-a-study-of-a-moving-mass-coaxial-monocopter/},

year  = {2025},

date = {2025-05-20},

urldate = {2025-05-20},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {The evolution of aerial drone technology has led to a growing interest in innovative configurations that optimize efficiency and maneuverability. Among these, monocopters have emerged as a promising alternative to traditional quadcopters, offering higher thrust-to-loading area ratios and reduced mechanical complexity. This paper presents the design, simulation, and control strategies for a novel moving mass coaxial monocopter. By leveraging the concept of moving mass control, which dynamically adjusts the center of mass to achieve precise orientation and trajectory adjustments, this monocopter design eliminates the need for complex stabilization mechanisms. The study explores the structural design and aerodynamic advantages of the proposed configuration, emphasizing its potential for lightweight, energy-efficient, and long-endurance missions. A comprehensive simulation framework is developed to analyze the nonlinear dynamics of the system to address associated challenges. The findings highlight the moving mass coaxial monocopter's capability to maintain stability and maneuverability in diverse flight conditions, offering a versatile solution for applications requiring rapid responsiveness and extended operational duration.},

keywords = {Student Papers},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3826,

title = {3826. Assessment of the Feasibility of a Solar-Powered Airship for Mars},

author = {Yan Pozhanka and Mostafa Hassanalian},

url = {https://www.sawe.org/product/3826-solar-powered-airship-for-mars/},

year  = {2025},

date = {2025-05-20},

urldate = {2025-05-20},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {In recent decades, humanity has been actively exploring outer space around Earth, and in recent years, nearby celestial bodies. Existing types of automated research platforms do not allow for the coverage of large areas while enabling direct measurements within bodies that possess an atmosphere. Therefore, this article presents a lower-bound estimate of the mass of an electric airship capable of flying in the Martian atmosphere and carrying a small payload. The assessment is based on a maximally lightweight airship design, considering anticipated advancements in materials and equipment. An algorithm in MATLAB has been developed for estimation of airship parameters. The algorithm iteratively estimates the mass of the components and compares it with the lifting force until equilibrium is reached. The results show that a Martian airship can be realized with feasible mass and dimensions. However, these parameters may pose significant challenges for transportation and deployment. Thus, the implementation of such a project requires the development of new technologies and the creation of specialized materials.},

keywords = {Aircraft},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3827,

title = {3827. Dynamic Mass-Aware Trajectory Tracking of Airships Using Multi-Actors Proximal Policy Optimization},

author = {Rongwei Liang and Duc Thien An Nguyen and Samuel Maimako},

url = {https://www.sawe.org/product/3827-dynamic-mass-aware-trajectory-tracking-of-airships/},

year  = {2025},

date = {2025-05-22},

urldate = {2025-05-22},

booktitle = {84th SAWE International Conference on Mass Properties Engineering},

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

abstract = {Dynamic mass variations significantly influence the attitude and trajectory tracking performance of stratospheric airships. To address this challenge, this paper proposes a dynamic

mass-aware control algorithm for airships using Multi-Actors Proximal Policy Optimization (PPO), a deep reinforcement learning framework. We first establish a comprehensive airship dynamics model that explicitly accounts for varying mass characteristics, formulating the state space, action space, and reward function to capture the impact of payload shifts or fuel consumption on flight stability. Multi-Actors PPO, leveraging a clipped probability ratio objective, enhances policy update stability and data efficiency in the presence of mass disturbances.  Neural networks are employed to approximate the policy and value functions, while Generalized Advantage Estimation (GAE) further boosts optimization performance. Preliminary analyses under diverse flight conditions and dynamic mass scenarios suggest that the proposed approach can significantly outperform traditional controllers such as PID and LQR in terms of trajectory tracking accuracy and robustness. Consequently, it offers an effective and stable solution for dynamic mass-aware intelligent control in unmanned airship systems.},

keywords = {Aircraft - Commercial},

pubstate = {published},

tppubtype = {inproceedings}

}