SAWE Civil Aircraft

3844 Unintentional Lateral Imbalance Calculation Methodology for Freighter Aircrafts

Damian Yanez — Fri, 29 May 2026 17:16:02 +0000

Paper

Alejandro Fiestras Corcho: 3844. Unintentional Lateral Imbalance Calculation Methodology for Freighter Aircrafts. 2026.

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.

3827. Dynamic Mass-Aware Trajectory Tracking of Airships Using Multi-Actors Proximal Policy Optimization

Greg Ray — Sat, 30 Aug 2025 19:02:34 +0000

Paper

Rongwei Liang, Duc Thien An Nguyen, Samuel Maimako: 3827. Dynamic Mass-Aware Trajectory Tracking of Airships Using Multi-Actors Proximal Policy Optimization. 2025.

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.

3826. Assessment of the Feasibility of a Solar-Powered Airship for Mars

Greg Ray — Sat, 30 Aug 2025 18:45:18 +0000

Paper

Yan Pozhanka, Mostafa Hassanalian: 3826. Assessment of the Feasibility of a Solar-Powered Airship for Mars. 2025.

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.

SAWE RP A-4, 2024: Survey Methods for Establishment of Passenger, Bag and Carry-On Weights

Andy Brooks — Sat, 03 Feb 2024 17:41:35 +0000

Once it became clear that the Federal Aviation Administration (FAA) was taking an unorthodox approach to the administration of weight & balance programs with issuance of revision F of Advisory Circular 120-27, it also became clear that the concept of industry standards in this area was being devalued. As such, a desire to retain the ability to produce and use standards on an industry level was expressed by the aircraft weight & balance community. There are several reasons for application of standards, including establishment of a common baseline for assessment of passenger and bag weights. Availability of standards will also reduce an operator's willingness to assume risk to achieve competitive advantage. The opportunity to address this issue as an industry is being made available through a broad collaboration of subject matter experts who are selflessly donating their time to this effort. This document has been developed through collaboration with the Society of Aircraft Performance and Operations Engineers (SAPOE). This partnership between SAWE and SAPOE offers an excellent example of leveraging institutional domain knowledge from both communities and applying in an area of need where overlap exists. This document wouldn’t exist without the support of leadership from both SAWE and SAPOE. This document is intended to aid engineers and statisticians designing and executing passenger and passenger bag weight surveys for airplane operations conducted in compliance with United States Federal Aviation Administration requirements (14CFR120/121/125/135/91K) as controlled by Operations Specifications A096/A097/A098 and A099.

SAWE RP-8, 1997: Weight and Balance Data Reporting Forms for Aircraft (including Rotorcraft and Air-Breathing Unmanned Aerial Vehicles)

Andy Brooks — Wed, 06 Apr 2022 03:11:30 +0000

Superseded by SAWE RP A-8, 2015a: Weight and Balance Data Reporting Forms for Aircraft (including Rotorcraft and Air-Breathing Unmanned Aerial Vehicles)

This document provides standard weight forms, Parts I, II, and III hereof, for reporting of weight and balance data for aircraft (including rotorcraft), states the principles followed in the formulation of these forms, and furnishes instructions where necessary for uniform compilation of the required weight and descriptive data. In particular, this document provides the formats to be used in preparation of Group Weight Statements, Detail Weight Statements and Status Reports as defined by SAWE Recommended Practice No. 7 and U.S. Military Data Item Description DI- MGMT-81501. This document was derived from U.S. Military Specification MIL-STD-1374A. Sufficient detail is included to cover the majority of components for most fixed wing, rotary wing, and V/STOL type aircraft. Blank spaces are provided for “write-ins” to detail weights for advanced design vehicles, hypersonic structures, projected propulsion systems, etc. Care should be taken before adding a “write-in” to ascertain that a reasonably appropriate term is not already contained in the forms.

SAWE RP-1, 1982: Requirements for Aircraft On Board Weight and Balance System

Andy Brooks — Wed, 06 Apr 2022 03:11:14 +0000

Superseded by SAWE RP A-1, 1982a: Requirements for Aircraft On Board Weight and Balance System

In the immediate future, the On Board Weight and Balance System (OBWBS) application will probably only function as a check of the conventional weight and balance manifest. However, the intent of this specification is to provide a primary system of weight and balance control which is supported by a manifest system. Eventually, an OBWBS may be totally automatic providing a computerized check of all the mass property limitations involved; however, that kind of OBWBS hardware is currently beyond the scope of this document. The actual application of this specification is, of course, up to the user.

SAWE RP-6, 1999: Standard Coordinate Systems for Reporting the Mass Properties of Flight Vehicles

Andy Brooks — Wed, 06 Apr 2022 03:11:13 +0000

Superseded by SAWE STD A-6, 2023: Standard Coordinate Systems for Reporting the Mass Properties of Flight Vehicles

Anyone who has worked in the mass properties field for any length of time knows the problem: one person's X is another person's Y. Since the numerical values of the mass properties of an object are entirely dependent on the coordinate system chosen, it is essential that engineers include a precise definition of their coordinate system along with the mass properties data. To minimize confusion and to make the job of defining your coordinate system easier, the SAWE has adopted two standard coordinate systems: Standard "A" is used for aircraft or any other vehicle which "flies" Standard "S" is used for objects which orbit the earth The intent of this Standard is to reduce errors and costs associated with improperly defined coordinate axis systems. Although mass properties engineers will often be forced to use coordinate systems dictated by other parties, the SAWE strongly encourages you to use one of these standards whenever you have the freedom to choose your own coordinate system. The success of a standard of this type depends on its widespread use. You are encouraged to make copies of this standard and to attempt to influence flight dynamics engineers and others at an early stage of the design of a flight vehicle. It is very difficult to change coordinate definitions once a project in underway.

SAWE RP A-8, 2015a: Weight and Balance Data Reporting Forms for Aircraft (including Rotorcraft and Air-Breathing Unmanned Aerial Vehicles)

Andy Brooks — Tue, 05 Apr 2022 21:45:00 +0000

This document provides standard weight forms, Parts I, II, and III hereof, for reporting of weight and balance data for aircraft (including rotorcraft), states the principles followed in the formulation of these forms, and furnishes instructions where necessary for uniform compilation of the required weight and descriptive data. In particular, this document provides the formats to be used in preparation of Group Weight Statements, Detail Weight Statements and Status Reports as defined by SAWE Recommended Practice No. A-7 and U.S. Military Data Item Description DI-MGMT-81501. This document was derived from U.S. Military Specification MIL-STD-1374A. Sufficient detail is included to cover the majority of components for most fixed wing, rotary wing, V/STOL and UAV type aircraft. Blank spaces are provided for “write-ins” to detail weights for advanced design vehicles, hypersonic structures, projected propulsion systems, etc. Care should be taken before adding a “write-in” to ascertain that a reasonably appropriate term is not already contained in the forms.

SAWE RP A-1, 1982a: Requirements for Aircraft On Board Weight and Balance System

Andy Brooks — Tue, 05 Apr 2022 21:45:00 +0000

SAWE RP A-12, 2016. Standard Weight Report for Aviation Components

Andy Brooks — Tue, 05 Apr 2022 21:44:00 +0000

Scope This Recommended Practice (RP) is intended for reporting and monitoring the evolution of essential Mass Properties data associated with Aviation components throughout all phases of a product’s lifecycle. Purpose To provide one standard format that aviation industry suppliers uniformly adopt for assessing, monitoring and reporting to an OEM the evolution of component mass properties characteristics in all lifecycle phases that is agreed with and developed by interested parties gathered in a SAWE Standard Practices Committee Consensus Body.