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Full-Text Articles in Engineering

Examining Failures Of Kc-135 Boom Assemblies Using Survival Analysis, Benjamin D. Miller Mar 2023

Examining Failures Of Kc-135 Boom Assemblies Using Survival Analysis, Benjamin D. Miller

Theses and Dissertations

The purposes of this study are to confirm the applicability of survival analysis for predicting recurrent failures of a component of a military aircraft and to provide practical insights to maintenance managers and mission planners. The results of this study also can help the United States Department of Defense improve the CBM+ program. This study was able to predict recurrent failures of the component using Nelson-Aalen cumulative estimates. In addition, this study used a Cox proportional hazards regression model with shared frailty for measuring the effect of covariates on recurrent failures and unidentified heterogeneity in the model, which warranted future …


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 …


Simulation And Piloted Simulator Study Of An Automatic Ground Collision Avoidance System For Performance Limited Aircraft, James D. Carpenter Mar 2019

Simulation And Piloted Simulator Study Of An Automatic Ground Collision Avoidance System For Performance Limited Aircraft, James D. Carpenter

Theses and Dissertations

The F-16 Automatic-Ground Collision Avoidance System (Auto-GCAS) has been a resounding success since implementation in Nov 2014, saving 8 pilots and 7 aircraft from Controlled Flight into Terrain (CFIT). However, there is no implemented Auto- GCAS for "heavy" performance limited aircraft. This research endeavors to expand on the success of F-16 Auto-GCAS to other aircraft in the Air Force inventory such as the C-130, C-17, and B-1. MIL-STD-1797 classifies performance limited aircraft as large, heavy, and low to medium maneuverability. Using a stitched Learjet-25D model (LJ-25D), an Auto-GCAS algorithm was developed to predict multiple escape-maneuver trajectories, compare these paths to …


Multi-Path Automatic Ground Collision Avoidance System For Performance Limited Aircraft With Flight Tests: Project Have Medusa, Kenneth C. Gahan Mar 2019

Multi-Path Automatic Ground Collision Avoidance System For Performance Limited Aircraft With Flight Tests: Project Have Medusa, Kenneth C. Gahan

Theses and Dissertations

A multi-path automatic ground collision avoidance system (Auto-GCAS) for performance limited aircraft was further developed and improved to prevent controlled flight into terrain. This research includes flight test results from the United States Test Pilot School's Test Management Project (TMP) titled Have Multi-Path Escape Decisions Using Sophisticated Algorithms (MEDUSA). Currently, the bomber and mobility air- craft communities lack an Auto-GCAS. The F-16 Auto-GCAS was proven successful for fighter-type aircraft with seven aircraft and eight lives saved from 2014 to 2018. The newly developed and tested Rapidly Selectable Escape Trajectory (RSET) sys- tem included a 5-path implementation which continuously updated at …


Secure Ads-B: Towards Airborne Communications Security In The Federal Aviation Administration's Next Generation Air Transportation System, Richard C. Agbeyibor Mar 2014

Secure Ads-B: Towards Airborne Communications Security In The Federal Aviation Administration's Next Generation Air Transportation System, Richard C. Agbeyibor

Theses and Dissertations

The U.S. Congress has mandated that all aircraft operating within the National Airspace System, military or civilian, be equipped with ADS-B transponders by the year 2020. The ADS-B aircraft tracking system, part of the Federal Aviation Administration's NextGen overhaul of the Air Transportation System, replaces Radar-based surveillance with a more accurate satellite-based surveillance system. However, the unencrypted nature of ADS-B communication poses an operational security risk to military and law enforcement aircraft conducting sensitive missions. The non-standard format of its message and the legacy communication channels used by its transponders make the ADS-B system unsuitable for traditional encryption mechanisms. FPE, …


Ballistic Flash Characterization Of Entry-Side Flash, David J. Peyton Sep 2012

Ballistic Flash Characterization Of Entry-Side Flash, David J. Peyton

Theses and Dissertations

Aircraft survivability is a broad subject that encompasses many fields and subjects. An important part of aircraft survivability is fire prevention. Flashes created by ballistic impacts are a very real threat to aircraft because they can start fires or cause explosions. In an effort to better protect against these flashes, this study seeks to further the understanding and characterization of them. Recent research on this subject has been greatly helped by the use of high-speed video footage of flash events. This footage has led to new algorithms and methodologies for how to characterize a flash. A preliminary predictive model of …


Impact Of Self-Reported Biases And Familiarity In A Baggage Screening Context, Scott W. Halwes Mar 2012

Impact Of Self-Reported Biases And Familiarity In A Baggage Screening Context, Scott W. Halwes

Theses and Dissertations

A common assumption is that items that evoke strong emotions are more easily recognized than items that do not evoke strong emotions (Bessette-Symons, 2008). For example, items such as guns or knives may evoke strong emotions within some people, and it may be presumed that these items may be more easily recognized by people that have strong emotions associated with them. If this is true, then perhaps these people would be more apt to locate these items in situations such as baggage screening services that rely on accurate detection of weapons for the public's safety. This study explores this reasoning …


Impact Of Decision Criteria On Federal Aviation Administration Certification Of Military Commercial Derivative Aircraft, Michael S. Low Mar 2012

Impact Of Decision Criteria On Federal Aviation Administration Certification Of Military Commercial Derivative Aircraft, Michael S. Low

Theses and Dissertations

The decision regarding whether to maintain Federal Aviation Administration certification of military commercial derivative aircraft (MCDA) can be extremely difficult due to the subjective nature of some of the associated costs and benefits. The purpose of this research is to help decision makers understand the level of impact those costs and benefits have on their decision, and how that impact may change over the life cycle of the MCDA fleet. Data regarding the various criteria involved in such decisions were collected from subject matter experts using the Delphi technique. This information was then incorporated into a decision support tool that …


Microelectromechanical Systems (Mems) Interrupter For Safe And Arm Devices, Steven S. Mink Mar 2006

Microelectromechanical Systems (Mems) Interrupter For Safe And Arm Devices, Steven S. Mink

Theses and Dissertations

This thesis addresses the development of a new micro-scale interrupter mechanism for a safe and arm device used in modern weapon systems. The interrupter mechanism often consists of a physical barrier that prevents an initial source of energy, in an explosive train, from being transferred to subsequent charges. In general, when the physical barrier is removed, the weapon is considered armed, and the charge is allowed to propagate. Several issues facing current safe and arm devices systems are the shrinking industrial base for manufacturing these devices and the desire for modern safe and arm devices to be compatible with next …


The Air Force Operational Risk Management Program And Aviation Safety, Matthew G. Cho Mar 2003

The Air Force Operational Risk Management Program And Aviation Safety, Matthew G. Cho

Theses and Dissertations

Aviation mishaps are extremely costly in terms of dollar value, public opinion, and human life, The Air Force drastically reduced Class A mishap rates in its formative years. The rate plummeted from 44.22 mishaps per 100,000 flight hours in 1947 to 2.33 mishaps in 1983 and has held steady around 1.5 mishaps since. The Air Force implemented the Operational Risk Management (ORM) program in 1996 in an effort to protect their most valuable resources: aircraft and aviators. An AFIT thesis conducted in 1999 by Capt Park Ashley studied the Army similar Risk Management (RM) program. Ashley concluded that since his …


Multimission Aircraft Design Study-Operational Scenarios, Nevin Coskuner Mar 2003

Multimission Aircraft Design Study-Operational Scenarios, Nevin Coskuner

Theses and Dissertations

In the most recent years, the Command, Control and Communications, Counter Measures, Intelligence, Surveillance and Reconnaissance (C3CMISR) aircrafts are used commonly in many NATO and UN Operations around the world. These aircrafts are AWACS, JSTARS, Rivet Joint, Compass Call and ABCCC. They provide close air support in the name of airborne surveillance, ground moving target surveillance, target reconnaissance, jamming, and command, control and communications issues in operational environments. Those aircrafts are tasked with a wide variety of missions than ever before in operational theaters and each one of them comprises a specific amount of cost and risk factors. As a …


Identification Of Critical Roles Of Program Managers And Contracting Officers, Daniel R. Shingledecker Mar 2001

Identification Of Critical Roles Of Program Managers And Contracting Officers, Daniel R. Shingledecker

Theses and Dissertations

The purpose of this research was to identify current disagreement among acquisition professionals in regards to their role and authority; and to identify benefits and risks associated with combining program management and contracting officer roles into a single position. The research questions were answered through a literature review and use of the Delphi technique. The literature review indicated that the DoD has been operating with multiple conflicting perceptions of authority among its key acquisition professionals. The literature also identified the need for complex organizations, such as DoD acquisition offices, to pair high levels of responsibility with equally high levels of …


Estimating Budget Relationships With A Leontief Input-Output Model, Guenever L. R. Shariff Dec 2000

Estimating Budget Relationships With A Leontief Input-Output Model, Guenever L. R. Shariff

Theses and Dissertations

Forty years ago, the Office of the Secretary of Defense proposed using the Leontief input-output model to assess tradeoffs in the Department of Defense's (DoD) budget. We demonstrate that the Leontief input-output model can assess tradeoffs in the Air Force's budget. To increase one part of the Air Force's budget, we need to know the interrelationships between that budget area and the other areas. In this research, we look at different methods of how the functional areas might interact. We demonstrate our methodology on two data sets - DoD and the Air Force aggregate budget data. By looking at how …


Toxicity Of Tolyltriazole To Gram-Positive Coccus Microorganisms, Heather L. Mitchell Mar 2000

Toxicity Of Tolyltriazole To Gram-Positive Coccus Microorganisms, Heather L. Mitchell

Theses and Dissertations

Maintaining safe flight operations, military and civilian, in cold weather requires the use of de-icing fluids. Glycols, the primary component of de-icers, have been extensively studied. Water and additives such as corrosion inhibitors and other performance enhancing chemicals make up the remaining portion of de-icing fluids. Little research has been conducted on the additives, but several are suspected toxins to microorganisms, therefore the EPA regulates the disposal of spent de-icing fluids. Tolyltriazole, a corrosion inhibitor found in de-icing fluids, is a suspected human carcinogen. It is also known to be moderately toxic to microorganisms based on Microtox results. The purpose …


Analysis Of Uh-60 Blackhawk Safety Controls Using Value Focused Thinking And Monte Carlo Simulation, Roger D. Gallan Jr. Mar 2000

Analysis Of Uh-60 Blackhawk Safety Controls Using Value Focused Thinking And Monte Carlo Simulation, Roger D. Gallan Jr.

Theses and Dissertations

In the past few years, Army aviation accidents have been on the rise, due largely to increases in mission frequency and complexity, and diminishing resources. The magnitude of the resulting losses (casualties, dollars, equipment) has prompted the Commanding General of the Army Safety Center to demand a complete examination of the way safety hazards and subsequent safety controls are evaluated and selected. This project integrates value focused thinking, Monte Carlo simulation, and integer programming in response to this demand by developing and using a methodology that effectively identifies and evaluates portfolios of controls. An integer program generates portfolios of controls …