SAWE Technical Papers

@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},

year  = {2025},

date = {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}

}

@inproceedings{3822,

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

author = {Mark Beyer},

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{3816,

title = {3816. EMPOWERING MASS PROPERTIES ENGINEERS WITH ARTIFICIAL INTELLIGENCE: TRANSFORMING ESTIMATION, ANALYSIS, AND OPTIMIZATION},

author = {William Boze},

year  = {2025},

date = {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{3835,

title = {3835. Vibration Characterization for Active Damping in a 2U CubeSat Payload for Rocketry Applications},

author = {Ellen Froelich},

year  = {2025},

date = {2025-05-20},

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

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

abstract = {Vibration damping is essential to protect certain flight equipment and avionics, ensuring a successful flight in rocketry. The two main types of damping are passive

and active damping. Passive damping uses materials to absorb shock and vibration during flight. This works under certain conditions but is not always sufficient. Active

damping, however, offers more effective results. This damping method uses a data processor to assess the system’s vibration state and sends this information to a

controller, which determines the appropriate action to reduce the vibration on the system, acting as a closed loop system.

To implement effective damping, the vibrations the system experiences during flight need to be characterized. This includes determining the modes of vibration the system

has, their locations, frequencies, and resulting displacements. The objective of the University of Minnesota: Twin Cities Rocket Team’s 2U CubeSat payload for the 2025

International Rocket Engineering Competition (IREC) is to characterize these vibrations that the CubeSat is experiencing during a flight to an altitude of 30,000

feet. Once the vibrations are characterized, an active damping system can be programmed and developed to reduce those vibrations.},

keywords = {Student Papers},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3833,

title = {3833. Path Planning for Autonomous Unmanned Ground Vehicles in Underground Mining},

author = {Narges Bagheri and Darion Vosbein and Hassan Khaniani and Mostafa Hassanalian},

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 = {Autonomous robotic navigation in underground mining environments poses significant challenges due to confined spaces, poor lighting, and the absence of GPS signals. This study presents the design and implementation of an autonomous navigation system for the Husky unmanned ground vehicle (UGV), utilizing LIDAR-based Simultaneous Localization and Mapping (SLAM) within the Robot Operating System (ROS) framework. The system enables real-time mapping, obstacle avoidance, and both global and local path planning in GPS-denied environments. The performance of navigation system was validated through simulations in Gazebo and field tests in two physical environments: the Bunker Lab at New Mexico Tech and the Missouri S&T Experimental Mine. These tests confirmed the Husky’s ability to navigate complex terrain and generate accurate 2D occupancy maps without prior environmental knowledge.},

keywords = {Student Papers},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3830,

title = {3830. A Mallard-Based Flapping Wing Aerial System},

author = {Darion Vosbein and Jared Upshaw and Samuel Maimako and Mostafa Hassanalian},

year  = {2025},

date = {2025-05-20},

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

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

abstract = {Unmanned vehicles (UVs), commonly known as drones, have experienced rapid technological advancements in recent years, revolutionizing a wide range of industries from logistics to agriculture. In the context of ecological and environmental sciences, drones have emerged as a powerful tool for wildlife monitoring, enabling researchers to collect high-resolution data with minimal disruption to animal behavior and natural habitats. However, conventional drones—characterized by their rigid structures, propeller noise, and artificial appearance—can inadvertently introduce stress or behavioral changes in wildlife due to their intrusive presence.

In response to these limitations, the field has seen a growing interest in biomimicry, the engineering approach that draws inspiration from biological forms and behaviors. This method has proven particularly promising in the design of bioinspired drones that more closely resemble natural wildlife in both appearance and movement. By mimicking the locomotion and visual profile of animals, such devices can better blend into ecosystems and minimize their ecological footprint.

Among these innovations are drones that leverage taxidermy—using the preserved bodies of animals as the basis for mechanical systems. This approach creates a highly realistic façade that enhances stealth and enables the devices to be perceived as part of the natural environment. The use of taxidermized birds, especially species like the Mallard duck, has demonstrated potential for both aquatic and aerial surveillance applications. Flapping-wing drones and swimming robotic birds combine the advantages of camouflage with functional mobility, allowing for the discreet collection of data in wetlands and other sensitive ecosystems.

These biomimetic devices offer a non-invasive alternative to traditional tracking methods, such as tagging or trapping, which can be harmful or stressful to wildlife. Additionally, the integration of modern sensors, microcontrollers, and remote operation capabilities into these platforms allows for real-time data acquisition and expanded deployment range, opening new avenues for ecological monitoring and conservation efforts.

As biomimetic drone development continues to evolve, it holds great promise for reshaping how we observe and study wildlife—providing tools that are not only technologically sophisticated but also harmoniously integrated into the environments they monitor.},

keywords = {Student Papers},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3828,

title = {3828. Biomimetic Swimming Taxidermy Duck Robot},

author = {Darion Vosbein and Kathryn McDonagh and Sean Goodyear and Mostafa Hassanalian},

year  = {2025},

date = {2025-05-20},

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

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

abstract = {Unmanned vehicles (UVs), commonly known as drones, have experienced rapid technological advancements in recent years, revolutionizing a wide range of industries from logistics to agriculture. In the context of ecological and environmental sciences, drones have emerged as a powerful tool for wildlife monitoring, enabling researchers to collect high-resolution data with minimal disruption to animal behavior and natural habitats. However, conventional drones—characterized by their rigid structures, propeller noise, and artificial appearance—can inadvertently introduce stress or behavioral changes in wildlife due to their intrusive presence.

In response to these limitations, the field has seen a growing interest in biomimicry, the engineering approach that draws inspiration from biological forms and behaviors. This method has proven particularly promising in the design of bioinspired drones that more closely resemble natural wildlife in both appearance and movement. By mimicking the locomotion and visual profile of animals, such devices can better blend into ecosystems and minimize their ecological footprint.

Among these innovations are drones that leverage taxidermy—using the preserved bodies of animals as the basis for mechanical systems. This approach creates a highly realistic façade that enhances stealth and enables the devices to be perceived as part of the natural environment. The use of taxidermized birds, especially species like the Mallard duck, has demonstrated potential for both aquatic and aerial surveillance applications. Flapping-wing drones and swimming robotic birds combine the advantages of camouflage with functional mobility, allowing for the discreet collection of data in wetlands and other sensitive ecosystems.

These biomimetic devices offer a non-invasive alternative to traditional tracking methods, such as tagging or trapping, which can be harmful or stressful to wildlife. Additionally, the integration of modern sensors, microcontrollers, and remote operation capabilities into these platforms allows for real-time data acquisition and expanded deployment range, opening new avenues for ecological monitoring and conservation efforts.

As biomimetic drone development continues to evolve, it holds great promise for reshaping how we observe and study wildlife—providing tools that are not only technologically sophisticated but also harmoniously integrated into the environments they monitor.},

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},

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{3825,

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

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

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{3823,

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

author = {Mark Beyer},

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{3821,

title = {3821. Agile Weight Maturity},

author = {Roman Aman and Melissa Gray},

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{3817,

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

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

year  = {2025},

date = {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{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{3811,

title = {3811. Parametric Weight Substantiation And Uncertainty Quantification For Aircraft Design},

author = {Andy Walker},

url = {https://www.sawe.org/product/3811-parametric-weight-substantiation-and-uncertainty-quantification-for-aircraft-design/},

year  = {2024},

date = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

pages = {46},

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

organization = {SAWE},

abstract = {Creating and substantiating weight estimation methods for future aircraft design has been completed using open-source data. Legacy best-practices were explored in corelating weight estimating relationships for configurations relating to manned fighters, carrier-based fighters, jet transports, business jets, military intelligence/ surveillance/ reconnaissance (ISR), and general aviation. Statistical methods were used to validate that each parametric method follows a normal, Gaussian distribution. This paper also makes some novel observations regarding statistical weight regressions, including: the fallacy of removing data points in regressions, the good and bad side of adding weight growth margins, employing detailed vs coarse weight method calibration factors, and how legacy aircraft validation helps in the big picture but hurts in the details.},

keywords = {Aircraft, Other Engineering},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3809,

title = {3809. Practical Limits of Precision when Tracking Weight Changes in Series Production},

author = {Doug Fisher},

url = {https://www.sawe.org/product/3809-practical-limits-of-precision-when-tracking-weight-changes-in-series-production/},

year  = {2024},

date = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

pages = {12},

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

abstract = {Calculafing and tracking the weight impact of design changes during aircraft product development and series producfion is an important part of ensuring a program's success. Computer model-based design tools and databases allow miniscule impacts to be calculated, documented, and tracked - each at a cost to the program in non-recurring hours. There exists a pracfical lower limit for weight impacts, below which the impact can be considered negligible. The cost of tracking impacts below this limit is wasteful and should be avoided. This paper will describe a method for determining this lower limit, along with the associated benefits and risks.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3808,

title = {3808. Implementing Effective Weight Management Strategies in Shipyards: A Practical Approach},

author = { Randi Fikkan and Runar Aasen and Stein Bjørhovde},

year  = {2024},

date = {2024-05-22},

urldate = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

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

abstract = {This paper investigates contemporary weight management practices in shipyards, focusing on both weight and center of gravity (CG) estimation, along with the associated follow-up and monitoring procedures. While emphasizing newbuild projects, it also examines modifications and retrofits. Beyond detailing current practices, the paper proposes enhancements and alternative approaches to weight and CG management. It begins with a foundational overview of weight management's definition and significance and extends to encompass weight control principles, procedural frameworks, and weight reporting. The discussion covers estimation methods, publicly available data for estimation, the influence of project types on weight management, uncertainty considerations, and the comparison between CAD data and weight data.

This paper will also compare the current situation with the findings from SAWE Paper 3244 (Weight Control at Ulstein Shipyard, Norway) from 2002, providing useful insights into how weight management practices in shipyards have evolved and where improvements still can be made.},

keywords = {Marine},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3807,

title = {3807. Why Measure?},

author = {Bob Cipolli},

url = {https://www.sawe.org/product/3807-why-measure/},

year  = {2024},

date = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

pages = {2},

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

abstract = {Mass properties determination is critical for the mission success of a variety of objects. From spacecraft and airplanes to computer disc drive heads and golf balls. Weight, center of gravity, moment of inertia and product of inertia can be estimated through computer modeling but those values are lacking in real world tolerances that may not reflect the entire process of design, machining, assembly, and environment. This paper reviews some of the reasons for measuring those mass properties and the possible repercussions of flawed estimates.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3806,

title = {3806. SAWE Handbook Section 2.2 Solid Properties Excel Formulae},

author = {Robert L. Zimmerman },

url = {https://www.sawe.org/product/3806-sawe-handbook-section-2dot2-solid-properties-excel-formulae/},

year  = {2024},

date = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

pages = {17},

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

abstract = {The SAWE Handbook Section 2 has figures and formulae for many shapes, including (Section 2.1) Plane Areas, (Section 2.2) Solids, and (Section 2.3) Shells, Section 2.4) Thin Rods. This paper will concentrate on Solids, Section 2.2, and convert the formulae from this section into equivalent Excel equations that can be used to derive the mass, center(s) of gravity, and the mass moments of inertia of these solid shapes. The resulting values can then be used in determining the mass properties of these and composite entities in further calculations.},

keywords = {General},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3805,

title = {3805. Measuring Reaction Points during Aircraft Weighing using an Inexpensive Laser},

author = {Damian P. Yañez },

url = {https://www.sawe.org/product/3805-measuring-reaction-points-during-aircraft-weighing-using-an-inexpensive-laser/},

year  = {2024},

date = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

pages = {12},

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

abstract = {Maintaining an aircraft's weight and balance within specified limits throughout all phases of its lifecycle is critical to its performance and the safety of its crew, passengers, and maintenance personnel. Measuring the weight and center of gravity (CG) of the aircraft in its Empty Weight configuration is typically the starting point for all subsequent weight and balance calculations. This procedure is often accomplished by placing load cells on jacks underneath the aircraft at three (or more) known locations relative to the aircraft coordinate system, raising and leveling the aircraft, measuring the weights on each cell, and calculating the moments and resultant CG. If the load cells are positioned at fixed reaction points on the airframe, the locations of the cells are easily known. If the load cells are positioned beneath the landing gear, the reaction points must be measured since the gear typically moves with an increase or decrease in load. Finding the true dimensions of these reaction points can be difficult, time consuming, and prone to error. This paper describes a method for quickly and accurately determining the reaction locations for the jacks under gear (JUG) method using an inexpensive laser distance meter. All aircraft designs are unique, so the process may not work exactly as described here, but the hope is that this paper will stimulate discussion and ideas for extending the concept as needed to fit your situation.},

keywords = {Aircraft},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3802,

title = {3802. The Mass Growth Factor – Snowball Effects in Aircraft Design},

author = {John Singh Cheema and Dieter Scholz},

url = {https://www.sawe.org/product/2802-the-mass-growth-factor-snowball-effects-in-aircraft-design/},

year  = {2024},

date = {2024-05-22},

urldate = {2024-05-22},

booktitle = {83rd International Conference, virtual (2024)},

pages = {64},

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

abstract = {Purpose – This project work shows a literature survey, clearly defines the mass growth factor, shows a mass growth iteration, and derives an equation for a direct calculation of the factor (without iteration). Definite values of the factor seem to be missing in literature. To change this, mass growth factors are being calculated for as many of the prominent passenger aircraft as to cover 90% of the passenger aircraft flying today. The dependence of the mass gain factor on requirements and technology is examined and the relation to Direct Operating Costs (DOC) is pointed out.



Methodology – Calculations start from first principles. Publically available data is used to cal-culate a list of mass growth factors for many passenger aircraft. Using equations and the result-ing relationships, new knowledge and dependencies are gained.



Findings – The mass growth factor is larger for aircraft with larger operating empty mass ratio, smaller payload ratio, larger specific fuel consumption (SFC), and smaller glide ratio. The mass growth factor increases much with increasing range. The factor depends on an increase in the fixed mass, so this is the same for the payload and empty mass. The mass growth factor for subsonic passenger aircraft is on average 4.2, for narrow body aircraft 3.9 and for wide body aircraft (that tend to fly longer distance) 4.9. In contrast supersonic passenger aircraft show a factor of about 14.



Practical implications – The mass growth factor has been revisited in order to fully embrace the concept of mass growth and may lead to a better general understanding of aircraft design. Social implications – A detailed discussion of flight and aircraft costs as well as aircraft de-velopment requires detailed knowledge of the aircraft. By understanding the mass growth fac-tor, consumers can have this discussion with industry at eye level.



Originality/value – The derivation of the equation for the direct calculation of the mass growth factor and the determination of the factor using the iteration method for current aircraft was not shown in the examined literature.},

keywords = {Aircraft},

pubstate = {published},

tppubtype = {inproceedings}

}