Impact of Parameter Accuracy on Aircraft Structural Integrity Estimates
The USAF initiated the Aircraft Structural Integrity Program (ASIP) over 40 years ago because of catastrophic, unanticipated, in-flight fatigue failures of in-service aircraft. In essence, ASIP is the management tool for the USAF to safely manage the fleet from initial operating capability through the design service goal and beyond. Since ASIP's inception, the USAF has not had a single catastrophic structural failure. The primary analysis tool to determine the fatigue life of a structural component in ASIP is linear elastic fracture mechanics (LEFM). In this effort, nine LEFM parameters were identified that affect the fatigue life: initial flaw assumption, boundary correction factor, load interaction models, crack growth rate data, stress intensity factor, threshold stress intensity factor, yield stress, and critical stress intensity factor.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Modern Airships
Modern airships by design are capable of short-take off and landings (STOL), and vertical take-off and landings (VTOL). This VTOL capability enables the airship to land practically anywhere, independent of most infrastructure support. This ability would allow deploying heavy forces to be picked up at their home-station and transported directly to a location directed by the Combatant Commander, bypassing the labor intensive and time consuming portions of the deployment process. The challenge facing DoD is determining if this type of transport is feasible and acceptable for military use. DoD has already sponsored two studies on two very different airship designs, thus demonstrating DoD is interested in the airship heavy transport concept. This monograph highlights some of the findings from those studies and looks at historically proven uses of airships and some contemporary uses as well. Contemporary transports, the deployment process, and the associated challenges for deployments are also discussed. Together this information is used to assess feasibility and acceptability of airships as heavy transports. This monograph concludes with a positive assessment for the airship and recommendations for how DoD should proceed toward the use of airships in the not too distant future.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Spacecraft Charging at Geosynchronous Altitudes
Spacecraft charging threatens to disable spacecraft components and adversely impact any satellite function. Electrostatic charge, and especially discharge, can hinder the proper operation of, or destroy, spacecraft components, thereby rendering the spacecraft ineffective or inoperative (Prokopenko and Laframboise, 1980:4125). The level of charging is dependent on the particle energy (speed) distribution. Current spacecraft design and materials provide limited protection against the dangers of electrostatic discharge, and active measures such as beam emission are also employed. The goal of this thesis is to investigate the kappa distribution as an alternative to the Maxwellian distribution as a method of predicting the onset of significant spacecraft charging by extending the research of Lai and Della-Rose (2001). Their work demonstrated the existence of critical (electron) temperatures above which the onset of significant spacecraft charging occurs. Below this critical temperature, significant charging does not occur (Lai and Della-Rose, 2001:927). Space plasmas are known to exhibit non-Maxwellian distributions at high (> 10 keV) energies (Vasyliunas, 1968:2840), and this knowledge provides the motivation for extending the work of Lai and Della-Rose to the kappa distribution. Solving the current balance equation is central to this area of research. Data from Los Alamos National Laboratory scientific instruments onboard geosynchronous satellites were analyzed to determine the efficacy of the kappa approach. However, the results of this thesis suggest that the kappa distribution, though superior to the Maxwellian at modeling high-energy particles (electrons), may be no better at determining charging onset.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Multimission Aircraft Design Study, Payload
It is proposed that a Multi-Mission Aircraft (MMA) be prepared to combine some or all the functions of the aging AWACS, JSTARS, RIVET JOINT, COMPASS CALL, and ABCCC fleet. Three different thesis studies have been developed by three Air Force Institute of Technology GSE students to show the feasibility of replacing the current aging fleet with one or more MMA platforms. This is the thesis in which the payload issues have been examined. Within this thesis, two different alternative architectures, which are One Tail Number and Different Tail Numbers including nine different configurations, have been considered. Estimated payload characteristics of these alternatives have been compared to those of Boeing 767-400ER, which is the aircraft selected as the baseline for MMA platform. Reduced life cycle cost, increased measure of aircraft specifications, and minimum risk are the main objectives pursued by means of several systems engineering and aircraft design methodologies.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Performance Capability of a Damaged Lighter-Than-Air Vehicle Operation in the Near Space Regime
This study investigates the ability of a high-altitude airship to maintain lift following the compromise of its lifting gas envelope. Accepted engineering principles are applied to develop a model that provides comparative analyses for airship depressurization alternatives following hull compromise. Specifically, maintaining lifting gas envelope overpressure to provide controllability in wind currents while sacrificing some buoyancy is compared with allowing envelope depressurization to occur with the goal of maintaining greater buoyancy as long as possible. The model provides insights to alternatives for recovering a damaged vehicle and its payload. In particular, the analysis demonstrates that maintaining the ability to navigate while forfeiting buoyancy can provide additional down-range maneuver capability. In some cases preserving the airship's hull overpressure for some period of time following compromise, vice allowing a slow depressurization to atmospheric equilibrium, extends the distance a damaged airship can sustain controlled navigation as much as eighty percent. However, the airship will forfeit nearly twenty percent of the altitude it would otherwise preserve by not forcing a constant hull overpressure.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
An Evaluation of Formic Acid as an Electron Donor For Palladium Catalyzed Destruction of Nitroaromatic Compounds
The Department of Defense is responsible for over 2,000 hazardous waste sites containing nitroaromatic compounds (NACs) such as 2,4,6-TNT, 2,4- and 2,6-DNT that resulted from the production and use of munitions throughout the nation and world. NACs are typically persistent in natural environments, though they can be oxidized or reduced under engineered conditions. NACs and their reduction products are toxic chemicals and suspected human carcinogens. Both TNT and 2,4-DNT are listed as priority pollutants by the U.S. EPA. This study investigates the effectiveness of using a palladium (Pd) catalyst in concert with formic acid as an electron donor to reduce NACs. If the reduction reaction is rapid and complete, without producing hazardous daughter products, the process may have application as an in situ treatment technology to remediate NAC-contaminated groundwater. In this study, formic acid was added into NAC-contaminated water flowing through a laboratory column filled with Pd catalyst. Experimental results using 2,4-DNT as a model NAC indicate reduction rates are dependent on pH, formic acid concentrations, and NAC concentrations.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Satellite Attitude Control Using Atmospheric Drag
Attitude control is a requirement for most satellites. Many schemes have been devised over the years including control moment gyros, reaction wheels, spin stabi- lization and gravity gradient stabilization. For low Earth orbits, the Earth's atmo- sphere can have an affect on a satellite's orbit and attitude. Using the atmosphere to control spacecraft attitude has been researched in the past however very little re- search has been done using an active feedback control system to maintain spacecraft attitude. This research effort examines the feasibility of using the atmosphere to actively control a spacecraft's attitude using drag panels. Several variables affect the drag force, of which, projected area is the only variable that can be changed easily. Adding controllable drag panels to a satellite gives the ability to change the projected area as well as the location of the projected area. The result of manipulating the projected areas is a force that is not aligned with the center of gravity, resulting in an external torque on the spacecraft. Although these torques are very small, on the scale of micro-Newton meters and smaller, over time these torques can be used to change the spacecraft's attitude. A linear computer model was created using a proportional controller. This model was used to evaluate the effectiveness of using drag panels for attitude control. Results from the simulation show that the spacecraft can recover from disturbance torques that may cause a change in attitude very effectively especially at low altitudes (200-300km).This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Intermediate Aircraft Maintenance
Most combat aircraft systems today utilize three levels of repair capability; organizational, intermediate, and depot. This is referred to as three-level maintenance. The relative difficulty of the repair action typically increases from the organizational level through the intermediate and depot levels. Most of the time, "flight line" and minor repair actions are classified as organizational level repairs. These include removing and replacing line replaceable units (LRUs) and accomplishing minor repairs on the aircraft. Intermediate level, or off-equipment maintenance, require special equipment and more personnel proficiency than organizational level repairs. Intermediate level repairs include performing tests on LRUs and accomplishing needed repairs through the removal and replacement of faulty components called shop replaceable units (SRUs). Repair shop technicians conduct fault isolation procedures with test equipment to identify faulty components. If the repair of the LRU is beyond the capability of the intermediate repair shop then the asset is declared to be not repairable this station (NRTS) and is shipped to the Air Logistics Center (depot) for repair. The depot level of maintenance repair typically requires specific industrial capabilities for component overhauls or major modifications.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Characterization Of Chlorinated Solvent Degradation in a Constructed Wetland
Widespread chlorinated ethene contamination of aquifers coupled with high costs of current treatment technologies demand innovative remediation solutions. Wetlands, maintaining anaerobic and aerobic zones promoting the complete degradation of chlorinated ethenes such as Tetrachloroethylene (PCE), could be the answer. This thesis characterized the chlorinated solvent contamination levels in three strata of an upward flow constructed wetland. Analysis of samples was accomplished by purge-and-trap gas chromatography. Water quality parameters, Dissolved Oxygen (DO), Oxidation Reduction Potential (ORP), pH, Conductivity, and Temperature, were also measured in monitoring wells with a water monitoring sonde. After removing data outliers caused by short-circuiting flow, PCE concentrations declined from an average of 32.59 ?簣 0.699 ppb (?簣 95% confidence interval) in the inflow stream to an average of 0.171 ?簣 0.807 ppb in the upper layer (a 99.3% reduction).This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Piloting the USAF's UAV Fleet
The primary objective of this research project was to examine the four most frequently proposed alternatives for staffing current and future Air Force UAVs designed to operate within the manned airspace environment: rated officers, non-rated officers, enlisted, and contractors. This study examined three major issues, airspace integration, operational employment, and Air Force cultural considerations for each of the alternatives. A review of Air Force UAV operator experience was initially identified followed by an evaluation of projected potential future UAV capabilities and their impact on staffing considerations. The objective findings derived from an Air Force Research Laboratory (AFRL) survey concluded that it was feasible to train any of these alternative populations to operate at least the only current UAV system in this category, the Predator. Unfortunately, there was insufficient data to extrapolate these findings to future systems. In addition, the AFRL was unable to determine specific training programs for these various options. However, perhaps more important than the physical abilities simply to operate the vehicle is the comprehensive requirements to successfully employ them as weapon systems. In addition, there are the internal and external organizational considerations. These UAVs represent an entirely new category of vehicles in the national and international airspace structure. They also represent a potential shift in who projects conventional combat power within the Air Force. Because of these major issues, this paper concludes that for the foreseeable future, pilots should operate this category of UAVs for the United States Air Force. Although this study placed considerable emphasis on the Predator system, the analysis also was intended to apply to future UAV systems operating within the manned controlled airspace.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Long Term Quadrotor Stabilization
The work of this thesis focuses on the IMU and getting the best performance possible out of the IMU to achieve better long term stability and a better navigation solution. This is done in two ways. First, the IMU accelerometer output is examined to determine if it is possible to use accelerometers to determine attitude. If the quadrotor is stationary or moving at constant velocity, the roll and pitch angles can be determined. Additionally, the accelerometers can be used to determine angular accelerations and angular rates which are integrated to determine heading. The second approach models the quadrotor and uses the models in Kalman Filters along with the IMU measurements to determine the best possible navigation solution.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Computational Design of Upperstage Chamber, Aerospike, and Cooling Jacket for Dual-Expander Rocket Engine
To increase the performance of the current US satellite launch capability, new rocket designs must be undertaken. One concept that has been around since the 50s but yet to be utilized on a launch platform is the aerospike, or plug nozzle. The aerospike nozzle concept demonstrates globally better performance compared to a conventional bell nozzle, since the expansion of the jet is not bounded by a wall and therefore can adjust to the environment by changing the outer jet boundary. A dual-expander aerospike nozzle (DEAN) rocket concept would exceed the Integrated High Payoff Rocket Propulsion Technology initiative (IHPRPT) phase three goals. This document covers the design of the chamber and nozzle of the DEAN. The validation of the design of the DEAN are based on the model in Numerical Propulsion System Simulation (NPSS TM), added with the nozzle design from Two-Dimensional Kinematics (TDK 04TM). The result is a rocket engine that produces 57,231 lbf (254.5 kN) of thrust at an Isp of 472 s. Additionally, the oxygen wall is made of silicon carbide, with a melting point of 5580 R (3100 K), and has a maximum temperature at the throat of 1625 R (902 K).This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Impact of Parameter Accuracy on Aircraft Structural Integrity Estimates
The USAF initiated the Aircraft Structural Integrity Program (ASIP) over 40 years ago because of catastrophic, unanticipated, in-flight fatigue failures of in-service aircraft. In essence, ASIP is the management tool for the USAF to safely manage the fleet from initial operating capability through the design service goal and beyond. Since ASIP's inception, the USAF has not had a single catastrophic structural failure. The primary analysis tool to determine the fatigue life of a structural component in ASIP is linear elastic fracture mechanics (LEFM). In this effort, nine LEFM parameters were identified that affect the fatigue life: initial flaw assumption, boundary correction factor, load interaction models, crack growth rate data, stress intensity factor, threshold stress intensity factor, yield stress, and critical stress intensity factor.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Whole Spacecraft Vibration Isolation
The Department of Defense has identified launch vibration isolation as a major research interest. Reducing the loads a satellite experiences during launch will greatly enhance the reliability, lifetime, and payload to structure ratio. DoD satellite programs stand to benefit significantly from advances in vibration isolation technology. This study explores potential hybrid vibration isolation control designs versus passive designs. A simple lumped mass dynamic model of a satellite and a representative launch vehicle was designed using Simulink. The analysis focuses on the various sources of transient launch accelerations such as aero-acoustic loads, separation events, wind gusts, and motor induced vibration. The passive vibration suppression design reduced axial "bounce" modes. Further reductions were made possible with an added active controller. The results of modeling indicate that as much as a 90 percent improvement in loads on the satellite were recognized from the combination of active and passive vibration control techniques. The model also explored the response of a sub-component of the satellite payload. For passive isolation the sub-component remained near its low baseline level of response, but for hybrid isolation the sub-component is exposed to greater levels of loading as a function of passive isolation frequency.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Performance Capability of a Damaged Lighter-Than-Air Vehicle Operation in the Near Space Regime
This study investigates the ability of a high-altitude airship to maintain lift following the compromise of its lifting gas envelope. Accepted engineering principles are applied to develop a model that provides comparative analyses for airship depressurization alternatives following hull compromise. Specifically, maintaining lifting gas envelope overpressure to provide controllability in wind currents while sacrificing some buoyancy is compared with allowing envelope depressurization to occur with the goal of maintaining greater buoyancy as long as possible. The model provides insights to alternatives for recovering a damaged vehicle and its payload. In particular, the analysis demonstrates that maintaining the ability to navigate while forfeiting buoyancy can provide additional down-range maneuver capability. In some cases preserving the airship's hull overpressure for some period of time following compromise, vice allowing a slow depressurization to atmospheric equilibrium, extends the distance a damaged airship can sustain controlled navigation as much as eighty percent. However, the airship will forfeit nearly twenty percent of the altitude it would otherwise preserve by not forcing a constant hull overpressure.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Building a Better Aircraft Maintenance Officer
Several changes have occurred in the maintenance operating environment and in aircraft maintenance officer training and development activities since the last known academic review in 2002.1 Chief among them are the reorganization of the wing structure into the Combat Wing Organization; creation of the 21AX Career Field Education and Training Plan (CFETP), the Maintenance Officer Intermediate Course (MOIC), and the Advanced Maintenance and Munitions Officer's School (AMMOS); as well as the introduction of the 21A/M Developmental Team (DT). In addition, several changes in the national security environment, including the DoD basing structure and the type of wars we fight, continue to shape the maintenance environment.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Organic Army Unmanned Aircraft Systems
Although Unmanned Aircraft Systems (UASs) are proliferating in the joint operational environment at an astonishing rate, they are meeting only a fraction of the demand. The USAF's failure to meet this insatiable demand for armed intelligence, surveillance, and reconnaissance (ISR) caused the Army to develop their own "organic" UAS capability. Does it make sense to spend $1.02B to create an aircraft capable of ranging the entire joint operations area, yet control it at the Army division level? This paper argues it is not in the best interest of the joint fight and it recommends alternative solutions for the Army's integration of "theater-capable" UASs. The research paper analyzes five contentious issues in a problem-solution format based on the USAF's MQ-1B Predator and the Army's planned MQ-1C Sky Warrior unmanned systems. The five issues include centralized versus organic control, rated pilots versus operators, airspace control methods, service interdependence, and deployment footprint. This research paper paints a picture of the current environment by looking at the situation from both the USAF and Army perspectives. This situation is not conducive to effective joint operations, and it will continue to deteriorate as the Army brings high altitude UASs online. This paper finds that the Army's decentralized, low altitude system composed primarily of rotary-wing assets historically coexisted underneath the Air Force's centrally controlled fixed-wing system. But the addition of more capable UASs, like Sky Warrior, brought the Army system up into the USAF system--where the two systems are no longer capable of providing an environment conducive to joint operations.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Air Traffic Control Capabilities
New world-wide requirements to equip aircraft for ADS-B surveillance systems provides an opportunity for the USAF to develop and field a lower-cost, more accurate, and integrated Air Traffic Control and Command and Control system. Such a system would improve command and control in military, civilian, and joint civ/mil environments, particularly in areas not suitable for traditional radar operations due to infrastructure, security, or terrain.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
The Need for a Global Space-Traffic-Control Service
Losing a satellite to an accidental on-orbit collision is no longer hypothetical, but real and increasingly likely. As a result, the need for global space-traffic control must be addressed by the space-faring nations, especially the United States. The fiscal and national security ramifications are too significant to ignore. The replacement cost of a satellite, perhaps hundreds of millions of dollars, is the most obvious impact. But, this may be the most trivial consideration. The greatest concern is the potential catastrophic loss of vital communications, navigation, weather, and other services we depend on for daily global commerce and defense. As a matter of national prestige, leadership and security, the US Government should endeavor to establish an international institution to govern global space traffic. As in 1944, the United States should convene a similar international conference with the purpose to establish such a service like the ICAO.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Can You Create the Universal Pilot for the Universal Aircraft
Traditionally, fighter aircraft training has focused on exploiting the capabilities in the missions each fighter was designed for. Though multi-role aircraft are nothing new, the capabilities designed into the F-35 Lightning II span the largest mission set for a fighter to date. The breadth of mission areas the F-35 has capabilities in threatens to exceed a pilot's ability to maintain expertise in and train to effectively. In the past, the need for specialization in fighter missions occurred due to the limited capabilities of each aircraft. Current multi-role aircraft such as the F-18 and F-16 have exposed the pilot as a potential limiting factor in the number of capabilities in which a fighter squadron can effectively train.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Transforming the Aircraft Inspection Process
The next five years promise to bring significant changes to the Air Force's current operating environment. This change is prompted by several budget initiatives to provide funds for vital programs that include recapitalizing the growing inventory of aging aircraft. Some of these initiatives target manpower billets in specific areas across the Active, Reserve, and Guard forces with a projected goal of reducing full-time equivalent positions by approximately 40,000. One initiative, released as Programmed Budget Decision (PBD) 716 in December 2005, directs the offsets to be fully executed by the end of FY11 across most Air Force Specialty Codes (AFSCs) to minimize huge losses in a few areas. Within the past year, the period to complete the offsets has been accelerated to end of FY09.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Cockpit Automation and Mode Confusion
The application of computer technology in modern cockpits has resulted in sophisticated automation that has created situations of mode confusion where the pilot is uncertain about the status or behavior of cockpit automation. Based on current levels of cockpit automation, classifications of mode confusion, and clinical knowledge concerning human cognitive and attentive processes, could an audible attention step help mitigate unrecognized mode error? The Software-Hardware-Environment-Liveware model forms a framework for the analysis of government and academic research concerning pilot automation experiences and use, cognitive models, information and decision processing, and the auditory attention channel. Pilot experiences and several aircraft accidents suggest that mode error is both common and potentially dangerous enough to warrant attempts at mitigation. Studies indicate that the monitoring requirement levied by automation lowers pilot system situational awareness without providing sufficient or proper feedback. Operators can also suffer from cognitive lockup and task channeling, which makes attention diversion difficult. An auditory input might provide an effective attention step if it demands appropriate attention, provides situation reporting, and offers problem guidance.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
The Wind and Beyond
How ideas about aerodynamics first developed and how the science and technology evolved to forge the airplane into the revolutionary machine that it became is the epic story told in this projected six-volume series.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Employment of Unmanned Aircraft Systems for Canadian Forces Anti-Submarine Warfare
Currently, more than 30 nations are developing or manufacturing more than 250 models of Unmanned Aircraft Systems (UAS). Dramatic increases in UAS platform performance and payload capacity in recent medium and high altitude, long-endurance designs permitted customers to add more systems and capabilities to their UAS design requirements. These advances resulted in UAS platform capabilities that meet or exceed legacy manned fixed wing Intelligence Surveillance and Reconnaissance (ISR) and maritime surveillance platform capabilities. Employment of Medium-Altitude, Long-Endurance (MALE) and High-Altitude, Long Endurance (HALE) UAS in the anti-submarine warfare (ASW) role is rapidly becoming feasible through emerging technologies and expanded payload capacities, the most significant of which are secure high-bandwidth Beyond Line of Sight (BLOS) satellite datalink communications, miniature light-weight sonobuoys, and real-time shore-based acoustic processing. As a result, UAS may be a technically feasible future Canadian Forces (CF) ASW capability as a complementary or stand-alone alternative to manned fixed-wing and rotary-wing maritime ASW platforms.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Optimal Spacecraft Attitude Controlusing Aerodynamic Torques
This thesis introduces a method of three-axis spacecraft attitude control using only aerodynamic torques. Attitude actuation is achieved using four control panels mounted on the rear of a cubical spacecraft bus. The controller consists of an outer loop using linear state feedback to determine desired control torque and an inner loop to choose appropriate control panel angles. The inner loop uses a Jacobian-based approachto invert the nonlinear relationship between panel angles and generated torque. Controller performance is evaluated via simulations, which show that three-axis control is possible over a range of initial angles and angular rates. The analysis used partial accommodation theory as the basis for aerodynamic torque calculations and assumed a rotating atmosphere with an exponential density profile.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Modeling a Field Application of In Situ Bioremediation of Perchlorate-Contaminated Groundwater Using Horizontal Flow Treatment Wells
Perchlorate contaminated groundwater is rapidly becoming a significant environmental remediation issue for the Department of Defense. In this study, an existing numerical model that simulates the operation of a Horizontal Flow Treatment Well (HFTW) system to effect the in situ biodegradation of perchlorate through the addition of an electron donor is modified to include a submodel that describes bioclogging. Bioclogging restricts flow out of the HFTW due to the accumulation of biomass directly adjacent to the well. The modified model is then applied to an existing perchlorate contaminated site that will be used for an evaluation of the HFTW technology. Simulations were conducted to determine the impact of altering various engineered parameters on HFTW performance. Simulation results indicate that higher time averaged electron donor concentrations and HFTW pumping rates lead to more perchlorate degradation in terms of total mass of perchlorate removed.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Characterization Of Chlorinated Solvent Degradation in a Constructed Wetland
Widespread chlorinated ethene contamination of aquifers coupled with high costs of current treatment technologies demand innovative remediation solutions. Wetlands, maintaining anaerobic and aerobic zones promoting the complete degradation of chlorinated ethenes such as Tetrachloroethylene (PCE), could be the answer. This thesis characterized the chlorinated solvent contamination levels in three strata of an upward flow constructed wetland. Analysis of samples was accomplished by purge-and-trap gas chromatography. Water quality parameters, Dissolved Oxygen (DO), Oxidation Reduction Potential (ORP), pH, Conductivity, and Temperature, were also measured in monitoring wells with a water monitoring sonde. After removing data outliers caused by short-circuiting flow, PCE concentrations declined from an average of 32.59 ?簣 0.699 ppb (?簣 95% confidence interval) in the inflow stream to an average of 0.171 ?簣 0.807 ppb in the upper layer (a 99.3% reduction).This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Chromate Content Bias as a Function of Particle Size in Aircraft Primer Paint Overspray
Spray painting operations using chromate-containing primer paints produce particles which may expose workers to strontium chromate. Chromate contains hexavalent chromium (Cr(VI)) which is a confirmed human carcinogen. It is suspected that the smaller particles contain disproportionately less Cr(VI) than larger particles. In order to determine if a bias in chromate content exists, paint particles were collected and separated based on particle size and the Cr(VI) concentration was determined. Aviation primer paint from the DeSoto and Deft companies was sprayed in a booth and seven-stage cascade impactors were used to separate particles. The particles were grouped into fourteen distinct bins based on size within an overall range of 0.7 to 34.1 um mass median aerodynamic diameter. The total mass of dry paint collected in each bin was quantified and the paint was analyzed for Cr(VI) mass.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Analysis of Bacterial Population and Distribution in the Developing Strata of a Constructed Wetland Used for Chlorinated Ethene Bioremediation
Chlorinated hydrocarbons and their degradation products are among of the most common organic groundwater contaminates in the United States. These compounds attack the central nervous system in animals and can affect the photosynthesis of plants. These compounds are also resistant to degradation in the environment and, because of this, pose a risk to any ecosystem in which they are present. This study identified the dominant microbial species in a constructed treatment wetland at Wright-Patterson AFB, Dayton, Ohio using 16S rRNA gene sequence analysis. Samples were taken from three different depths and during each of the four seasons. These samples were compared with similar samples taken from an uncontaminated, control site located at Valle Greene wetland in Beavercreek, Ohio. The intent of the study was to measure differences between the microbial community of the treatment wetland and the control wetland. It was hypothesized that the bacteria found to degrade the materials in the lab would be present in the treatment wetland and has a higher population than a wetland free of contaminants. This hypothesis would help support the idea that the natural attenuation of chlorinated hydrocarbons is due primarily to biological factors.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Cycle Performance of a Pulse Detontation Engine With Supercritical Fuel Injection
Pulse detonation engines (PDE) rely on rapid ignition and formation of detonation waves. Because hydrocarbon fuels are composed typically of long carbon chains that must be reduced in the combustion process, it would be beneficial to create such reduction prior to injection of fuel into the engine. This study focused on PDE operation enhancements using dual detonation tube, concentric-counter-flow heat exchangers to elevate the fuel temperature up to supercritical temperatures. Variation of several operating parameters included fuel type (JP-8, JP-7, JP-10, RP-1, JP-900, and S-8), ignition delay, frequency, internal spiral length, and purge fraction.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
The Effects of Employing HVM on C-130 Aircraft at WR-ALC to Aircraft Availability
The objective of this research is to evaluate the impact of increasing the labor burn rate, one of the High Velocity Maintenance (HVM) core tenets, and the transition of isochronal aircraft inspections from the field to the depots under the Single Maintenance Concept. This study focuses on depot maintenance data from WR-ALC for AFSOC C-130 aircraft to evaluate HVM effectiveness to improve the on-time delivery rate and increase aircraft availability rates for commanders in the field. Additionally, this project will discuss commercial industry best practices that best achieve higher labor burn rates and the challenges of implementing these practices into the traditional depot maintenance process. In order to quantitatively assess the potential effects of HVM on depot production, this project examines WR-ALC C-130 depot maintenance data from July 2007 to May 2011, and interviews WR-ALC depot personnel in the HVM office and 560 AMXS. During the interviews the full catalog of HVM briefings were also reviewed extending to the inception of the HVM's program at WR-ALC. Moreover, this study utilized a field questionnaire to gather the average aircraft down-days in relation to depot-prep, post-depot, isochronal inspections, and home station checks. With the depot maintenance data and assistance from the WR-ALC and field Subject Matter Experts (SMEs) the labor burn rate tenet and Single Maintenance Concept of HVM are evaluated to assess the effect on reducing C-130 aircraft production flow days, improving on-time aircraft delivery rates, and increasing aircraft availability.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
A Comparative Analysis of the Cost Estimating Error Risk Associated With Flyaway Costs Versus Individual Components of Aircraft
A shrinking workforce, unstable budgets, and rapidly changing objectives under stricter time constraints characterize today's cost analysis and acquisition environment. In concert with this environment, cost analyst positions have rapidly decreased as demonstrated by Aeronautical Systems Centers 54% decline in total authorized slots from 1992 to 2001. The question is how to deal with this 'more with less' mentality.The purpose of this research is to investigate and measure the risks associated with taking a macro versus micro approach to aircraft cost estimation. By analyzing the fidelity of a cost estimate developed at the flyaway cost level versus a cost estimate developed at the individual components level, this research provides guidelines for appropriate allocation of cost analyst resources. This objective is accomplished by looking at the cost estimation error risk of recurring costs at level one of the Work Breakdown Structure (WBS) and at level two of the WBS.Results show that there is a statistically significant difference between estimating at the differing WBS levels. However, from a practical standpoint, the difference in dollar terms is too small to be considered significant. As a result, program manager should allocate resources based on other constraints such as time allotted to complete the estimate or required level of visibility into the estimate.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Analysis and Forecasting of Air Force Operating and Support Cost for Rotary Aircraft
This research explores forecasting techniques to estimate the Cost per Flying Hour for Air Force Helicopters. Specifically, this research evaluates three separate forecasting techniques to predict the CPFH for better estimating and budgeting by the USAF. It starts by empirically analyzing the Operating and Support cost by CAIG categories for each helicopter. For forecasting purposes the actual CPFH figures were compiled from FY96 to FY03 for a total of eight MAJCOMs flying the MH-53J/M, the HH-60G, or the UH-1N helicopters. The research explores the use of a 3-year moving average, the single exponential smoothing method, and the Holt's linear method.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
A Comparative Analysis of Singe-State-to-Orbit Rocket and Air-Breathing Vehicles
This study compares and contrasts the performance of a variety of rocket and airbreathing, single-stage-to-orbit, reusable launch vehicles. Fuels considered include bi-propellant and tri-propellant combinations of hydrogen and hydrocarbon fuels. Astrox Corporation's HySIDE code was used to model the vehicles and predict their characteristics and performance. Vehicle empty mass, wetted area and growth rates were used as figures of merit to predict the total cost trends of a vehicle system as well as the system's practicality. Results were compared to those of two-stage-to-orbit reusable launch systems using similar modeling methods. The study found that single-stage-to-orbit vehicles using scramjet airbreathing propulsion outperform rocket systems. Findings also demonstrate the benefits of using hydrocarbon fuel in the early phases of ascent to reduce the size and mass of launch vehicles.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Assembly, Integration, and Test Methods for Operationally Responsive Space Satellites
Current government and industry standards in spacecraft testing result in an Assembly, Integration, and Test (AIT) timeline greater than six months. These standards will not support the vision of Operationally Responsive Space (ORS) to deploy a satellite within six days to fill an urgent need. Using the Air Force Research Laboratory's Plug-and-Play Satellite (PnPSat), multiple Rapid AIT trials were conducted. By exercising the AIT process with various spacecraft configurations and personnel, methods for reducing or modifying traditional testing regimen were investigated.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Modeling Vertical Flow Treatment Wetland Hydraulics to Optimize Treatment Efficiency
An upward Vertical Flow Treatment Wetland (uVFTW) at Wright Patterson AFB designed to bioremediate contaminated groundwater exhibits hydraulic short-circuiting. Prior studies estimated that groundwater flowed through less than 50% of the wetland's volume, and that the mean residence time was significantly less than the nominal residence time, which was calculated assuming flow through the entire wetland volume. The objective of this research was to investigate how uVFTW hydraulics affects treatment efficiency, and to propose design strategies to maximize treatment efficiency. A groundwater flow and contaminant transport model of a uVFTW that couples hydraulics and degradation kinetics was built and applied to estimate the effectiveness of engineering solutions aimed at improving treatment efficiency. Model simulations indicate that the engineering solutions improve hydraulic residence times, volumetric utilization, and treatment efficiency over the existing wetland, but also that increasing hydraulic residence time only has a significant impact on treatment efficiency when the time scale for the biodegradation process is similar to the wetland residence time. Degradation kinetics must be quantitatively understood to determine an optimum range for hydraulic residence time, and to ensure that resources are not wasted in an attempt to improve hydraulic performance where no improvement in degradation performance is possible.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
An Investigation Into Robust Wind Correction Algorithms for Off-the-Shelf Unmanned Aerial Vehicle Autopilots
This research effort focuses on developing methods to design efficient wind correction algorithms to "piggy-back" on current off-the-shelf Unmanned Aerial Vehicle(UAV) autopilots. Autonomous flight is certainly the near future for the aerospaceindustry and there exists great interest in defining a system that can guide and controlsmall aircraft with high levels of accuracy. The primary systems required to command thevehicles are already in place, but with only moderate abilities to adjust for dynamicenvironments (i.e., wind effects), if at all. The goal of this research is to develop asystematic procedure for implementing efficient and robust wind effects corrections toexisting autopilots used on small Unmanned Aerial Vehicles. The research willinvestigate the feasibility of an external dynamic environment control algorithm as ameans of improving current, off-the-shelf autopilot technology relating to small UAVs.The research then presents three main focuses. First, a determination of the estimatedwinds utilizing the existing, on-board sensors. Second, the development of a windcorrection algorithm that incorporates simple mathematical principals to counter the 2-Dimensional wind forces acting on the aircraft; and third, the integration of that windcompensator into the on-board navigational system. This "piggy-back" algorithm mustassimilate smoothly with the current GPS technologies to provide acceptable and safeflight path following. The design procedures developed were demonstrated in simulationand with flight tests on the SIG Rascal 110 UAV. This report builds the framework fromwhich current wind correction research at AFIT and the ANT Center is based.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
AMC's Hydrogen Future
The purpose of this research is to compare the costs associated with the transition to hydrogen aircraft for Air Mobility Command (AMC) to the costs of continuing using JP-8. Using current technology, air mobility aircraft can be designed to use liquid hydrogen instead of JP-8. This transformation will be capital intensive. A model was built that converted current AMC JP-8 usage to liquid hydrogen usage and calculated the costs of the infrastructure for that transition.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Performance Characterization of a Three-Axis Hall Effect Thruster
he research presented here represents the first efforts to operate and quantify the performance of a three-axis Hall effect thruster. This thruster is based on the Busek BHT-200 and used a novel construction with three orthogonal faces and a common magnetic core to reduce size and weight. Operating procedures for the thruster were developed and thrust and current density measurements were performed and compared with the baseline BHT-200. The three-axis thruster was successfully operated in single, double and triple face configurations. Distinct jet plume and ball plume modes were observed. Inverted pendulum thrust stand readings in the single face mode indicated that the three-axis thruster produced considerably lower thrust, specific impulse and thrust efficiencies than the BHT-200. Beam current density measurements conducted using a guarded Faraday probe showed significant differences in plume divergence angle, total beam current and current density distributions between the different faces and different operating modes. Results showed three-axis thruster efficiency and stability improved with more operating faces. Improvements to the three-axis thruster design and thrust stand configuration for use with the thruster were enumerated. Suggestions for refinement to experimental methodologies to optimize testing with the three-axis thruster were made and additional diagnostic techniques were described.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
An Investigation of Starting Techniques for Inward Turning Inlets at Flight Speeds Below the On-Design Mach Number
The purpose of this study was to create and investigate starting techniques aimed at allowing complex, three dimensional inward turning inlets to start by swallowing the shock wave associated with un-started inlets. The designed techniques were rooted in supersonic diffuser theory and the Kantrowitz limit, and the techniques attempted to alleviate the over contraction that occurs in inward turning inlets at flight speeds below the on-design Mach number. Five cases, three geometries at two flow conditions, and the base non-modified inlet at the two different flow conditions were generated and all were numerically simulated using a commercially produced numerical solver, CFD++. The simulations were computed using the inviscid Navier-Stokes/Euler equations in a steady state analysis to generate the shock wave, followed by a transient analysis to allow the shock to move in time. The results of the investigation show that all five cases proved to be sub-optimal as none were able to successfully swallow the shock during the transient simulation. However, the results from this analysis indicate that the slit case, designs that extended the initial spill areas of the inlet, appear to hold the most potential in the creation of a successful starting technique. The slit case holds the most potential because the slit Mach 2.7 case was just as effective as the slot Mach 2.7 case, yet the slit area was half the size as the designed slots. Future research should attempt to characterize the effects of slits at different Mach numbers and at various complexities of inlet and slit geometry.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Optimization of Hybrid-Electric Propulsion Systems for Small Remotely-Piloted Aircraft
Small electric-powered remotely-piloted aircraft (RPA) used by today's warfighters for intelligence, surveillance, and reconnaissance (ISR) missions lack desired endurance and loiter times, while the acoustics and thermal signatures of those configured with internal combustion engines (ICE) may make them unpractical for ISR. Outfitting RPA with parallel hybrid-electric propulsion systems (H-EPS) would meet the military's needs by combining the advantages of both systems while reducing fuel consumption and environmental impacts. An analysis tool was created, using constrained static optimization, to size the H-EPS components. Based on the RPA's required power and velocity for the endurance phase, an electric motor (EM) can be designed or selected and matched with a commercial off-the-shelf (COTS) propeller for maximum efficiency. The ICE is then sized for the RPA's required power and velocity for the cruise phase.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Integrating Automated Multi-Disciplinary Optimization in Preliminary Design of Non-Traditional Aircraft
Current methods of aircraft conceptual design lack the ability to quickly generate detailed analysis, particularly of nontraditional designs such as blended wing body craft. This study developed a method to resolve this problem by creating a flexible, parametrically driven conceptual model in an object-oriented, adaptive modeling environment from which analysis and optimization may rapidly be performed. These object-oriented techniques are incorporated into a traditional conceptual design process. All objects inherit dependency-tracking and demand-driven calculations. Design Analysis was performed within the modeling language and utilized interfaces to other software packages. A detailed mesh, suitable for input into finite element analysis programs, was developed from the less detailed, geometric mesh created by the modeling program. The output from finite element analysis forms the basis for rapid changes in subsequent iterations of the design process. The demonstration focuses on a single parametric design model which transforms a conventional transport design into a blended wing body design. This single design is controlled by a limited set of geometric variables and produces optimal structural weight estimations while the designer addresses volumetric and cost requirements.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Reusable Launch Vehicle Design Implications for Regeneration Time
In last few years the Air Force Research Laboratory sponsored several research projects on Reusable Launch Vehicles (RLV) whose design, operation, and logistics requirements are intended to be much simpler than the Space Shuttle. Previous researchers developed a model that simulated the post-landing, ground maintenance and prelaunch operations of a RLV in order to evaluate how its design parameters affect the logistics operations. However, the next step was to investigate the effects and interactions of all the factors used in the existing simulation model in a single experiment that deals with the huge number of possible design characteristics' combinations discovered in previous studies and varying resources like manpower, ground support equipment and facilities. The goal of this research is to recommend to the AFRL a preferred design strategy that could minimize the resource requirements in terms of equipment and manpower as well as turnaround time of logistics operations.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Medical Devices, Supporting Networks, and Their Vulnerabilities
With the implementation of "one Air Force, one network" under way it is important to look at how the Air Force plans to incorporate the medical field and its unique systems, networks, and mission. The medical field presents distinctive problems not seen in other areas. Open network vulnerabilities in the medical information systems not only pose a problem for the individual, but to the military service also. Possible security holes provide both access to vital military and personal information (end strength numbers, current status of personnel, social security), and a door way into the "network". Intruders now can possibly access command and control systems and other weapon systems. This research provides insight into the current and future information initiatives dealing with the Air Force's medical field and the Department of Defense's approach to system security. This research additionally looks at the laws and regulations dealing with privacy and ethical issues. This purview starts with the recently enacted Healthcare Insurance Portability and Accountability ACT (HIPPA), and concludes with the Laws of Armed Conflict. The research questions were answered through the use of a Case Study and a comprehensive literature review. The medical and network support teams from two Air Force medical facilities were the basis of this study.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Flight Dynamic Response of HALE Aircraft to KC-135 Flowfield
This research effort examines the static affects of a KC-135 flowfield on a flexible winged Sensorcraft model. The KC-135 flowfield data is generated by a vortex lattice code and integrated into Sensorcraft model for analysis. Building on previous research, a refueling situation was modeled to note the effects of the Sensorcraft at varying locations within the flowfield. The Sensorcraft model was analyzed for both rigid and flexible wings as a means of comparision. Flowfield locations of interest were determined and trimmed conditions were computed for each flowfield location.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Attitude Model of a Reaction Wheel/Fixed Thruster Based Satellite Using Telemetry Data
Attitude determination of satellites is normally the job of inertial instruments, such as gyroscopes, or through sensing instruments, such as star trackers orGlobal Positioning Satellites (GPS). Satellite health monitoring systems watch and determine if the satellite deviates from its normal operating attitudeorientation. Knowing the orientation of a satellite is essential in being able to control it in order to complete the satellite's designated mission. While there area multitude of ways to determine a satellite's orientation, very little research has been done on determining if the attitude of a satellite can be determineddirectly from telemetry data of the attitude control systems and an accurate spacecraft model. The fidelity of a satellite attitude determination model requiredto get reasonable predictions from using only telemetry data of the attitude controllers, such as thruster on/off indicators and reaction wheel rotor speeds, isinvestigated. Experimental tests using telemetry data received from the Air Force Institute of Technology's (AFIT) Simulated Satellite, SimSat, is used inverifying a Matlab model which outputs SimSat's orientation from SimSat's reaction wheel and thruster telemetry data. Software modeling results showed thatit is possible to determine a satellite's attitude from only the attitude controllers' telemetry data when the satellite's dynamic model is known.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
High Altitude Airship Station-Keeping Analysis
Lighter-than-air vehicles were once widely utilized by most major militaries. The airship's extended range and flight endurance made them the optimal vehicle for surveillance and reconnaissance. These flight characteristics have created new interest in using lighter-than-air vehicles as high altitude surveillance and communications platforms. Future Department of Defense plans include high altitude airships that will operate at near space altitudes and take advantage of the low wind region in the upper atmosphere located at approximately 24 km. A high altitude airship could provide 24- hour coverage of a target area if operated in this low wind region. This study investigated the station-keeping abilities of two such high altitude airships: a large/fast design (AS #1) and a smaller/slower design (AS #2). The two baseline airship designs were subjected to the same simulated yearlong station-keeping mission using realistic upper atmospheric wind data over the designated target of Baghdad. Actual wind data was generated by the Navy's Fleet Numerical METOC Detachment and used to model the movements of both baseline airships. Their station-keeping capacity was determined by the duration of time each vehicle spent inside the targets coverage radius (552 km). The AS #1 design remained inside the operational radius for 87.67% of the year and the AS #2 design was only operational for 39.45% of the year. Neither airship maintained its station for the entire yearlong mission. This study concluded that advancements are required in propulsion or power production to decrease the size of the airship designs and increase the vehicles maximum velocity in order to counter the upper atmospheric winds.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Aboveground Oil Storage Tanks
The BiblioGov Project is an effort to expand awareness of the public documents and records of the U.S. Government via print publications. In broadening the public understanding of government and its work, an enlightened democracy can grow and prosper. Ranging from historic Congressional Bills to the most recent Budget of the United States Government, the BiblioGov Project spans a wealth of government information. These works are now made available through an environmentally friendly, print-on-demand basis, using only what is necessary to meet the required demands of an interested public. We invite you to learn of the records of the U.S. Government, heightening the knowledge and debate that can lead from such publications.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
