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Full-Text Articles in Engineering

Utilizing The System Engineering Trade Study Analysis Method To Analyze Patient Aeromedical Evacuation, Sara Shaghaghi, Jeremy M. Slagley, Michael E. Miller, Gaiven Varshney Apr 2023

Utilizing The System Engineering Trade Study Analysis Method To Analyze Patient Aeromedical Evacuation, Sara Shaghaghi, Jeremy M. Slagley, Michael E. Miller, Gaiven Varshney

Faculty Publications

The US Air Force has gone through many aeromedical patient isolation transport system designs. The first designs were developed in response to the Ebola outbreak in 2014 and, more recently, the COVID-19 pandemic. The trade study analysis part of the system engineering design method was used to analyze the historic and current aeromedical patient contamination control transport systems. A trade study is a process that evaluates alternatives based upon various “-ilities”, such as reconfigurability, flexibility, durability, cost, and more, and performs a systematic analysis to aid designers in producing a ‘good’ design alternative given the large set of possible solutions. …


Optimal Scheduling Of Aircraft Test And Evaluation Fleets To Balance Availability For Testing And Training, Sarah E. Hoops Dec 2022

Optimal Scheduling Of Aircraft Test And Evaluation Fleets To Balance Availability For Testing And Training, Sarah E. Hoops

Theses and Dissertations

The 96th Test Wing at Eglin Air Force Base manually schedules a fleet of approximately 26 aircraft to conduct a range of missions over a one-to-two year planning period. This study automates the scheduling process, does so in a manner that optimizes multiple planning goals related to aircraft availability for training, and provides the 96th Test Wing with a software tool for the implementation that can be used by operational analysts within the command. We formulate the scheduling problem as a multiobjective, nonlinear, binary integer math program that seeks to maximize both the lowest percent of time any aircraft is …


Investigating Supply Parts Delivery Delay From Supply Depot To King Khaled Air Base In Royal Saudi Air Force, Rashed S. Alkhathami Dec 2022

Investigating Supply Parts Delivery Delay From Supply Depot To King Khaled Air Base In Royal Saudi Air Force, Rashed S. Alkhathami

Theses and Dissertations

Aircraft supply parts is an important factor in preparing the aircraft to do its mission. Due to delayed delivery of parts or inefficient delivery process, time may be lost waiting for aircraft supply parts, causing mission delay or failure. By tackling the delivery delay causes we can insure improvement on delivery process. In order to gather data for this thesis two different tools were used, aircraft parts data and an interview. Data was gathered from the F15 maintenance and supply squadrons in the Royal Saudi Air Force. Results of this research showed diverting in the main duty of supply depot …


Evaluating Performance Competencies In The Royal Saudi Air Force Engineering Directorate And Squadrons, Faisal A. Al Dawood Sep 2022

Evaluating Performance Competencies In The Royal Saudi Air Force Engineering Directorate And Squadrons, Faisal A. Al Dawood

Theses and Dissertations

The effectiveness of tasks performed by the directorate of aeronautical engineering and squadrons in RSAF directly impacts flight safety, which in turn influences the organization either positively or negatively. Therefore, improving engineers' competencies will improve the overall performance of the organization. The study refined and reconstructed a model, namely a T-shape competency model, to assess the engineers' competencies which revealed some management and competency-related deficiencies and concluded with managerial recommendations.


Root-Cause Analysis Of Rsaf Maintenance-Related Flight Safety Mishaps, Heaf H. Alqahtani Sep 2022

Root-Cause Analysis Of Rsaf Maintenance-Related Flight Safety Mishaps, Heaf H. Alqahtani

Theses and Dissertations

Poor maintenance is a major factor in many aviation mishaps. This is due to the fact that some maintenance activities are carried out improperly or overlooked as a result of human error. It is important to acknowledge that maintenance mistakes are a visible sign of deeper organizational issues. Therefore, adequate solutions to maintenance issues must consider organizational influences. Despite efforts to reduce the accident rate within the Royal Saudi Air Force (RSAF), the RSAF suffers from an increasing trend in mishaps attributed to maintenance. Therefore, safety data was analyzed to examine trends. Additionally, the Human Factors Analysis and Classification System …


Supply Chain Resilience: How Autonomous Rovers Empirically Provide Relief To Constrained Flight Line Maintenance Activities, Mary A. Stanton, Jason Anderson, John M. Dickens, Lance Champagne Jun 2022

Supply Chain Resilience: How Autonomous Rovers Empirically Provide Relief To Constrained Flight Line Maintenance Activities, Mary A. Stanton, Jason Anderson, John M. Dickens, Lance Champagne

Faculty Publications

Purpose – The purpose of this research is to explore the utility of autonomous transport across two independent airframe maintenance operations at a single location. Design/methodology/approach – This study leveraged discrete event simulation that encompassed real-world conditions on a United States Air Force flight line. Though the Theory of Constraints (TOC) lens, a high-demand, human-controlled delivery asset is analyzed and the impact of introducing an autonomous rover delivery vehicle is assessed. The authors’ simulations explored varying numbers and networks of rovers as alternative sources of delivery and evaluated these resources’ impact against current flight line operations. Findings – This research …


Pilot Development: An Empirical Mixed-Method Analysis, Jonathan Slottje, Jason Anderson, John M. Dickens, Adam D. Reiman Jun 2022

Pilot Development: An Empirical Mixed-Method Analysis, Jonathan Slottje, Jason Anderson, John M. Dickens, Adam D. Reiman

Faculty Publications

Purpose — Pilot upgrade training is critical to aircraft and passenger safety. This study aims to identify variances in the US Air Force C-130J pilot upgrade training based on geographic location and provide a model to enhance policy that will impact future pilot training efforts that lower cost and increase operator quality and proficiency.
Design/methodology/approach This research employed a mixed-method approach. First, the authors collected data and analyzed 90 C-130J pilots' aviation records and then contextualized this analysis with interviews of experts. Finally, the authors present a modified version of Six Sigma's define–measure–analyze–improve–control (DMAIC) that identifies and reduces the …


Transportation Service Level Impact On Aircraft Availability, Vincent Mclean, Adam D. Reiman Jun 2022

Transportation Service Level Impact On Aircraft Availability, Vincent Mclean, Adam D. Reiman

Faculty Publications

Purpose — Aircraft fail to meet mission capable rate goals due to a lack of supply of aircraft parts in inventory where the aircraft breaks. This triggers an order at the repair location. To maximize mission capable rate, the time from order to delivery needs to be minimized. The purpose of this research is to examine the case of three airfields for the order to delivery time of mission critical aircraft parts for a specific aircraft type. Design/methodology/approach — This research captured data from three information systems to assess the order fulfillment process. The data were analyzed to determine the …


Airworthiness Decision Factors In The Us Air Force, Derek N. Dennis Mar 2022

Airworthiness Decision Factors In The Us Air Force, Derek N. Dennis

Theses and Dissertations

There are multiple airworthiness (AW) certification paths for aircraft platforms and their modifications. Specifically, military commercial derivative aircraft (MCDA) have a unique opportunity to pursue either FAA certification, military certification or a combination of both. Policy tells MCDA programs to pursue FAA certification to the maximum extent possible, however, the policy lacks clarity regarding where that extent ends. This concept of extent encompasses multiple factors and the choice of an AW basis is a complex decision. Under ideal conditions the decision maker, the program manager, has the experience and insight to support their decision, however, this is not always the …


Examining Failures Of Kc-135s Using Survival Analysis, Vanessa I. R. Unseth Mar 2022

Examining Failures Of Kc-135s Using Survival Analysis, Vanessa I. R. Unseth

Theses and Dissertations

The United States Air Force manages an inventory of 396 KC-135 Stratotanker aircraft. With mission capability rates falling and total non-mission capability supply rates increasing, it is necessary to take a deeper look at recurrent failures. The study applies non-parametric and semi-parametric survival models to a dataset retrieved from LIMS-EV to look at the duration(s) until failure for the KC-135. Results of non-parametric models show cumulative failure rates increase as sorties or flight hours increase. In addition, semi-parametric models or Cox proportional hazards models with frailty confirm that locations or air bases are not associated with recurrent failures.


Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal, John M. Dickens, Lance Champaign, Aaron V. Glassburner, Jason R. Anderson, Timothy W. Breitbach Dec 2021

Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal, John M. Dickens, Lance Champaign, Aaron V. Glassburner, Jason R. Anderson, Timothy W. Breitbach

Faculty Publications

Purpose — Forecasting techniques improve supply chain resilience by ensuring that the correct parts are available when required. In addition, accurate forecasts conserve precious resources and money by avoiding new start contracts to produce unforeseen part requests, reducing labor intensive cannibalization actions and ensuring consistent transportation modality streams where changes incur cost. This study explores the effectiveness of the United States Air Force’s current flying hour-based demand forecast by comparing it with a sortie-based demand forecast to predict future spare part needs. Design/methodology/approach — This study employs a correlation analysis to show that demand for reparable parts on certain aircraft …


Shifting Satellite Control Paradigms: Operational Cybersecurity In The Age Of Megaconstellations, Carl A. Poole [*], Robert A. Bettinger, Mark Reith Oct 2021

Shifting Satellite Control Paradigms: Operational Cybersecurity In The Age Of Megaconstellations, Carl A. Poole [*], Robert A. Bettinger, Mark Reith

Faculty Publications

The introduction of automated satellite control systems into a space-mission environment historically dominated by human-in-the-loop operations will require a more focused understanding of cybersecurity measures to ensure space system safety and security. On the ground-segment side of satellite control, the debut of privately owned communication antennas for rent and a move to cloud-based operations or mission centers will bring new requirements for cyber protection for both Department of Defense and commercial satellite operations alike. It is no longer a matter of whether automation will be introduced to satellite operations, but how quickly satellite operators can adapt to the onset of …


A Simulation Modeling The Effects Of Maintenance Personnel On Aircraft Sortie Generation, Benjamin D. Huffman Mar 2021

A Simulation Modeling The Effects Of Maintenance Personnel On Aircraft Sortie Generation, Benjamin D. Huffman

Theses and Dissertations

Commanders and wargamers lack adequate tools to quickly determine the number of mission-capable (MC) aircraft and number of achievable sorties to support wargames and exercises. Even less understood is the impact of available maintenance personnel on sortie generation. The Expected-Number-of-In-Game-Mission-capable Aircraft (ENIGMA) simulation was recently developed to calculate the number of MC aircraft and number of sorties own accounting for the number and type of aircraft, scheduled sorties, mean-time-between-failure (MTBF), and mean-time-to-repair (MTTR). ENIGMA is extended by replacing the MTTR input with functions derived from actual numbers and types of maintenance personnel available. Functions in the form of response surface …


Display Design To Avoid And Mitigate Limit Cycle Oscillations (Lco) On The F-16c, David J. Feibus Mar 2021

Display Design To Avoid And Mitigate Limit Cycle Oscillations (Lco) On The F-16c, David J. Feibus

Theses and Dissertations

The U.S. Air Force F-16 Fighting Falcons flying characteristics and flight envelope are dynamic and defined by its external weapon stores configuration. The employment of its munitions at certain speeds can put the F-16 into a flutter-like state in which Limit Cycle Oscillations (LCO) are induced. In LCO, a pilots fine motor control might be hindered, and the aircraft may lose combat effectiveness until flight conditions are reduced. The current research attempted to provide pilots with a predictive feedback display to avoid an LCO-susceptible configuration by increasing their situation awareness about the consequences of employing certain munitions to their flight …


Air Combat Maneuvering Via Operations Research And Artificial Intelligence Methods, James B. Crumpaker Mar 2021

Air Combat Maneuvering Via Operations Research And Artificial Intelligence Methods, James B. Crumpaker

Theses and Dissertations

Within visual range air combat requires rapid, sequential decision-making to survive and defeat the adversary. Fighter pilots spend years perfecting maneuvers for these types of engagements, yet the emergence of unmanned, autonomous vehicle technologies elicits a natural question - can an autonomous unmanned combat aerial vehicle (AUCAV) be imbued with the necessary artificial intelligence to perform air combat maneuvering tasks independently? We formulate and solve the air combat maneuvering problem to examine this question, developing a Markov decision process model to control an AUCAV seeking to destroy a maneuvering adversarial vehicle. An approximate dynamic programming (ADP) approach implementing neural network …


Examining Military Cargo Pilots' Eco-Friendly Flying Intention, Ioan A. Gaitan Mar 2021

Examining Military Cargo Pilots' Eco-Friendly Flying Intention, Ioan A. Gaitan

Theses and Dissertations

The US Air Force is the largest operational energy consumer within the Department of Defense primarily due to aviation fuel use. Military pilots can play important roles in saving aviation fuel by flying aircraft in an eco-friendly manner. According to the theory of planned behavior (TPB), intention is the major predictor of behavior. This study tests two models based on TPB for understanding cargo pilots’ eco-friendly intentions when they conduct channel or logistics missions. The study found that attitude, subjective norm, and perceived behavior control were significant antecedents to intention in a multiple regression with aggregated scales.


Stereo Camera Calibrations With Optical Flow, Joshua D. Larson Mar 2021

Stereo Camera Calibrations With Optical Flow, Joshua D. Larson

Theses and Dissertations

Remotely Piloted Aircraft (RPA) are currently unable to refuel mid-air due to the large communication delays between their operators and the aircraft. AAR seeks to address this problem by reducing the communication delay to a fast line-of-sight signal between the tanker and the RPA. Current proposals for AAR utilize stereo cameras to estimate where the receiving aircraft is relative to the tanker, but require accurate calibrations for accurate location estimates of the receiver. This paper improves the accuracy of this calibration by improving three components of it: increasing the quantity of intrinsic calibration data with CNN preprocessing, improving the quality …


Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer Mar 2021

Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer

Theses and Dissertations

America's General Aviation sector has witnessed significant demographic shifts since the turn of the century. The number of certified, private pilots, non-fatal aircraft accidents, fatal aircraft accidents, and number of general aviation hours flown are all in decline. Meanwhile, the average age of an American private pilot has increased by several years. All of these factors indicate that the industry is in decline. This study determined via mathematical, linear regression that times relationship to the number of annual, fatal General Aviation accidents and the number of certified private pilots is negative. It also proved that the average age of the …


Aircraft Inspection By Multirotor Uav Using Coverage Path Planning, Patrick H. Silberberg Mar 2021

Aircraft Inspection By Multirotor Uav Using Coverage Path Planning, Patrick H. Silberberg

Theses and Dissertations

All military and commercial aircraft must undergo frequent visual inspections in order to identify damage that could pose a danger to safety of flight. Currently, these inspections are primarily conducted by maintenance personnel. Inspectors must scrutinize the aircraft’s surface to find and document defects such as dents, hail damage, broken fasteners, etc.; this is a time consuming, tedious, and hazardous process. The goal of this work is to develop a visual inspection system which can be used by an Unmanned Aerial Vehicle (UAV), and to test the feasibility of this system on military aircraft. Using an autonomous system in place …


Resilient Maintenance Infrastructure: Dynamic Repair Network Designs To Effectively Manage Supply Chain Disruptions, David W. Wallace Iii Mar 2021

Resilient Maintenance Infrastructure: Dynamic Repair Network Designs To Effectively Manage Supply Chain Disruptions, David W. Wallace Iii

Theses and Dissertations

Supply chains are facing numerous changes contributing to their increase in complexity and vulnerability to disruptions. Subsequently, decision-makers lack a transparent, generalizable tool to quantify supply chain resilience and assess additional resilience investments. This research facilitates a more profound understanding of the intricacies and interrelation of supply chain nodes and constructs. It integrates the Area under the Curve (AUC) metric to quantify performance or any organizational measure of competitive advantage amid a disruption. Due to its structural resemblance to various organizational platforms, the subset United States Air Force (USAF) F-16 engine repair and supply network is modeled employing discrete-event simulation. …


The Autonomous Attack Aviation Problem, John C. Goodwill Mar 2021

The Autonomous Attack Aviation Problem, John C. Goodwill

Theses and Dissertations

An autonomous unmanned combat aerial vehicle (AUCAV) performing an air-to-ground attack mission must make sequential targeting and routing decisions under uncertainty. We formulate a Markov decision process model of this autonomous attack aviation problem (A3P) and solve it using an approximate dynamic programming (ADP) approach. We develop an approximate policy iteration algorithm that implements a least squares temporal difference learning mechanism to solve the A3P. Basis functions are developed and tested for application within the ADP algorithm. The ADP policy is compared to a benchmark policy, the DROP policy, which is determined by repeatedly solving a deterministic orienteering problem as …


The Obstacles To The Modernization Of Common Support Equipment, J. Erik Ritschard Mar 2021

The Obstacles To The Modernization Of Common Support Equipment, J. Erik Ritschard

Theses and Dissertations

The current fleet of Common Support Equipment (CSE) is faced with a $2B funding disconnect that threatens 9 of the 12 USAF Core Functions. This research identifies the barriers to efforts to modernize CSE across the sustainment, acquisition, and maintenance communities. Using a qualitative, grounded theory methodology, the responses are explored of interviewed Support Equipment managers responsible for the sustainment and modernization of CSE. Significant barriers to current modernization efforts were exposed, resulting in expensive, duplicative, and unreliable equipment; concluding that the AF must change the way CSE is administrated, funded, and culturally understood to prevent future mission degradation.


Quantifying The Effects Of Aircraft Engine Upgrades On Operating And Support Costs, Bradford A. Myers, Edward D. White, Jonathan D. Ritschel, R. David Fass Jan 2021

Quantifying The Effects Of Aircraft Engine Upgrades On Operating And Support Costs, Bradford A. Myers, Edward D. White, Jonathan D. Ritschel, R. David Fass

Faculty Publications

For fixed wing aircraft within the U.S. Air Force, Operating and Support (O&S) costs encompass a large portion of total life cycle costs. O&S costs include fuel, maintenance, and engine upgrades. To the authors’ knowledge, no study to date has attempted to empirically quantify the realized effects of new aircraft engines on sustainment costs. Utilizing the Air Force Total Ownership Cost database, they focused on new engines appearing on the C-5s, C-130s, and C-135s. Although narrow in scope, results suggest newer engines have lower fuel costs. Maintenance costs for newer engines were not consistently higher or lower than the engines …


Modified C-17 Taxi Procedures: A Fuel Cost Savings Exploration, Michael Wells, Michael Krester, Benjamin Hazen, Jeffrey Weir Dec 2020

Modified C-17 Taxi Procedures: A Fuel Cost Savings Exploration, Michael Wells, Michael Krester, Benjamin Hazen, Jeffrey Weir

Faculty Publications

Purpose — This study aims to explore the viability of using C-17 reduced-engine taxi procedures from a cost savings and capability perspective. Design/methodology/approach — This study model expected engine fuel flow based on the number of operational engines, aircraft gross weight (GW) and average aircraft groundspeed. Using this model, the research executes a cost savings simulation estimating the expected annual savings produced by the proposed taxi methodology. Operational and safety risks are also considered. Findings — The results indicate that significant fuel and costs savings are available via the employment of reduced-engine taxi procedures. On an annual basis, the mobility …


The Effects Of Aircraft Use And Available Repar Spares On Aircraft Sortie Generaiton: A Long-Duration Logistical Wargaming Simulationtool, Nathaniel M. Choo Dec 2020

The Effects Of Aircraft Use And Available Repar Spares On Aircraft Sortie Generaiton: A Long-Duration Logistical Wargaming Simulationtool, Nathaniel M. Choo

Theses and Dissertations

A long-duration logistical wargame simulation tool that can provide quick insights into the daily aircraft availability and the daily number of missions accomplished for a variety of operational scenarios is developed. This simulation tool is designed to be a stepwise wargaming support tool for adjudication within long-duration logistical wargames and provides the user many capabilities including, but not limited to, the ability to have multiple bases and types of aircraft. Additionally, the user has the ability to control types of part failures, control parts availability, control maintenance capabilities, and control number of mission scheduled. Finally, the user can account for …


Investigation Of An Avionics Part Deficiencies In Royal Saudi Air Force Fleets, Nasser S. Alanazi Sep 2020

Investigation Of An Avionics Part Deficiencies In Royal Saudi Air Force Fleets, Nasser S. Alanazi

Theses and Dissertations

The Royal Saudi Air Force (RSAF) is experiencing a shortage in certain avionics parts due to a lack of reliability. This issue is causing a supply chain disturbance in the F1-15 fleet and the Hawk fleet. One of the factors behind this problem is the environmental effects in Saudi Arabia .The study will investigate and analyze the methods for the Improvement Cycle Processes and the Quality Management within the RSAF repair cycle. Finding show that, the discrepancies are rising during summer and fall time due to the environment change, Other finding were addressed in the study.


3d Printing For Solving Part Obscolescence, Ayman G. Alqarni Sep 2020

3d Printing For Solving Part Obscolescence, Ayman G. Alqarni

Theses and Dissertations

The purpose of this research was to highlight the issue of parts obsolescence and to highlight the possibility of using alternative methods to overcome parts shortage. Specifically, this thesis sought to answer the research question: is the three-dimensional printing technology (3D) an applicable approach to overcome part obsolescence. The research question was answered through data research and survey analysis. Notwithstanding, the diminished manufacturing sources and material shortages (DMSMS) management and other existing approaches, such as forecasting, contracting, and reverse engineering (RE), were discussed briefly in the literature review and profoundly in chapter IV to differentiate among applicable existing solutions toward …


Mc80: Quantifying Effect Of Fleet Health On Sortie Execution In F-16 Fleet, Kyle R. Gladney Mar 2020

Mc80: Quantifying Effect Of Fleet Health On Sortie Execution In F-16 Fleet, Kyle R. Gladney

Theses and Dissertations

By order of the Secretary of Defense, all of the US Air Force's F-16 units were tasked to improve their fleet health to a Mission Capability (MC) rate of 80 percent, as part of a Department of Defense-wide push to make its Critical Aviation Platforms, and the units that employ them, more ready and lethal. This study uses historical fleet health and sortie execution data captured from LIMS-EV (Weapon System Viewer, 2020) to create a multiple regression model that quantifies the value of increased fleet health, defined as either MC rate or Aircraft Availability (AA) rate, in terms of increasing …


Resilient Aircraft Sustainment: Quantifying Resilience Through Asset And Capacity Allocation, Zachary B. Shannon Mar 2020

Resilient Aircraft Sustainment: Quantifying Resilience Through Asset And Capacity Allocation, Zachary B. Shannon

Theses and Dissertations

Decision makers lack a clear, generalizable method to quantify how additional investment in inventory and capacity equates to additional levels of resilience. This research facilitates a deeper understanding of the intricacies and complex interconnectedness of organizational supply chains by monetarily quantifying changes in network resilience. The developed Area under the Curve metric (AUC) is used to quantify the level of demand that each asset allocation can meet during a disruptive event. Due to its applicability across multiple domains, the USAF F-16 repair network in the Pacific theater (PACAF) is modeled utilizing discrete event simulation and used as the illustrating example. …


Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal Mar 2020

Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal

Theses and Dissertations

Weapon System Sustainment (WSS) costs are growing at an increasing rate despite the vast efforts to reduce them. Researchers have attributed much of the cost increase to inaccurate demand forecasts for weapon system spare parts. In 2011, the forecast to sustain all United States Air Force (USAF) aircraft was 19% accurate and WSS costs per year have continuously increased. The purpose of this study is to explore a parsimonious change to aircraft component forecasting to reduce costly forecast error. This study substitutes flying hours with sorties for the purpose of demand forecasting. Many F-16 and B-52 spare parts are evaluated …