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Pitot tube-free airspeed estimation methods exist for fixed-wing and multirotor configurations, but lack direct applicability to hybrid unmanned air vehicles due to their wide flight envelope and changing dynamics during transition. This work proposes a novel synthetic air data system for the Variable Skew Quad Plane (VSQP) hybrid vehicle to allow airspeed estimation from hover to high speed forward flight and provide pitot tube fault detection. An Extended Kalman Filter fuses Global Navigation Satellite System (GNSS) and inertial measurements using model-independent kinematics equations to estimate wind and airspeed without the use of the pitot tube. The filter is augmented by a simplified vehicle force model. Pitot tube fault detection is achieved with a simple thresholding operation on the pitot tube measurement and the airspeed estimation residual. Accurate airspeed estimation was validated with logged test flight data, achieving an overall 1.62 m/s root mean square error. Using the airspeed estimation, quick detection (0.16 s) of a real-life abrupt pitot tube fault was demonstrated. This new airspeed estimation method provides an innovative approach for increasing the fault tolerance of the VSQP and similar quad-plane vehicles., Aerospace Engineering

Seabirds are expected to increase their flight height in tailwind and to increase their airspeed in headwind during goal-oriented flight to minimize their cost of transport. To understand how flapping birds respond to variability in wind speed and direction experienced during their commuting flights between their breeding colony and foraging areas, we measured the flight height and speed of black-tailed gulls Larus crassirostris using GPS loggers. We analyzed the relationships between these flight parameters and local wind speed and direction. Over the course of the 2016 to 2018 breeding seasons, we tagged 105 birds at 2 colonies in northern Hokkaido, Japan. A total of 90 flight track-lines within a 500 m radius of 5 coastal meteorological stations were analyzed. The median flight height ranged from 0 to 153.8 m, and the median ground speed and airspeed were between 18.6-82.1 and 19.5-93.0 km h-1, respectively. Gulls flew higher with greater tailwind speed, supporting the hypothesis that birds utilize greater wind assistance at higher altitudes. Furthermore, gulls increased their airspeed under strong headwind conditions, suggesting they adjust airspeed to achieve the most cost-effective speed to reach their destination. Better understanding the drivers of seabird flight height is key to assessing the potential for collisions with wind turbines in coastal and offshore wind farms. These findings provide useful information to reduce collisions with coastal and offshore wind facilities.

This project proposes and evaluates a novel concept for an airspeed instrument aimed at small hybrid unmanned aerial vehicles. The working principle is to relate the power spectra of the wall-pressure fluctuations beneath the turbulent boundary layer formed over the vehicle’s body to its airspeed. The instrument consists of two microphones, flush mounted on the UAV’s nose cone, that capture the pseudo-sound caused by the coherent turbulent structures, and a micro-controller that processes the signals from the microphones and computes the airspeed. Dedicated models were constructed, using data obtained from wind tunnel and flight experiments, that take the power spectra of the microphones’ signals as an input and provide the airspeed as an output. The model structure is a feed-forward neural network with a single hidden layer, trained using a second-order gradient descent algorithm, following a supervised learning approach. The models were validated using only flight data, with the best one achieving a mean approximation error of 0.043 m/s and having a standard deviation of 1.039 m/s. It was also shown that the airspeed could be successfully predicted for a wide range of angles of attack, given that they are known, thus necessitating the vehicle to be equipped with a dedicated angle of attack sensor., Aerospace Engineering

This paper puts forward a novel design for an airspeed instrument aimed at small fixed-wing tail-sitter unmanned aerial vehicles. The working principle is to relate the power spectra of the wall-pressure fluctuations beneath the turbulent boundary layer present over the vehicle’s body in flight to its airspeed. The instrument consists of two microphones; one flush-mounted on the vehicle’s nose cone, which captures the pseudo-sound caused by the turbulent boundary layer, and a micro-controller that processes the signals and computes the airspeed. A feed-forward single-layer neural network is used to predict the airspeed based on the power spectra of the microphones’ signals. The neural network is trained using data obtained from wind tunnel and flight experiments. Several neural networks were trained and validated using only flight data, with the best one achieving a mean approximation error of 0.043 m/s and having a standard deviation of 1.039 m/s. The angle of attack has a significant impact on the measurement, but if the angle of attack is known, the airspeed could still be successfully predicted for a wide range of angles of attack., Control & Operations, Aircraft Noise and Climate Effects, Control & Simulation

The ALFLEX (Automatic Landing Flight Experiment) flight experiment was carried out in Woomera in South Australia, and 13 landing trials beginning on July 6, 1996, were conducted. The landing performance of all flying vehicles is strongly influenced by the ground. This paper describes a ground effect analysis method based on the flight experiment data of unmanned nonthrust vehicle, and gives ground effect characteristics of the ALFLEX., ALFLEX(小型自動着陸飛行実験)の飛行実験は、オーストラリア南部のウーメラにおいて行われ、1996年7月6日から13回の着陸試験を行った。すべての模型飛翔体の着陸性能は、地面に強く影響された。この報告では、無人・無推力飛翔体の飛行実験データに基づいて地面効果を解析する方法を述べ、ALFLEX飛翔体の地面効果特性を示した。

The dual-engine failure checklist of the Airbus A320 states that the optimum airspeed at which the aircraft can be flown is the “green dot” speed when an engine restart is considered impossible. This is because the “green dot” speed maximizes the power-off glide range in wings-level flight. However, it is not known whether the “green dot” speed would still be the optimum airspeed if the power-off landing maneuver primarily consists of sharp turns. The objective of this study is to find out the optimum power-off glide speed for the A320 if the emergency landing maneuver primarily requires sharp turns rather than wings-level flight. For this purpose, the study analyzes a total-loss-of-power scenario, in which an A320 undergoes dual-engine failure due to bird strike during the initial climb-out, and attempts a turn-back maneuver to the departure runway. The results show that the optimum power-off glide speed would be the lowest selectable airspeed because it requires the lowest altitude loss to reach the departure runway, enables the most favorable bank angle history, and requires the shortest runway length for landing roll. Therefore, the statement that the “green dot” speed is the optimum power-off glide speed may be a misleading item in the dual-engine failure checklist of the A320 in emergency situations. The findings can be used to revise and improve the existing dual-engine failure checklist of the Airbus A320, which transports over 71.5 million annual passengers on U.S. air carriers (Research and Innovative Technology Administration [RITA], 2014). This study is also the first of its type to analyze the power-off glide performance of a commercial jet.

Supersonic combustion ramjet (scramjet) propulsion is a significant advancement in air-breathing propulsion technology. The X-51A WaveRider research vehicle recently set new aviation speed records by employing a scramjet engine in a specialized airframe designed to operate at hypersonic airspeeds. The X-51A was an unmanned scramjet demonstration vehicle designed and developed by the consortium of Air Force Research Laboratory (AFRL), Defense Advanced Research Projects Agency (DARPA), The Boeing Company, Pratt & Whitney Rocketdyne and the National Aeronautics and Space Administration (NASA) to meet the requirements of the United States Air Force (USAF) WaveRider program. The overall test objective of the X-51A program was to demonstrate a scramjet engine using endothermic hydrocarbon fuel, by accelerating a vehicle up to Mach 6+ after the vehicle was boosted to the altitude and airspeed conditions required for engine start. Four X-51A vehicles were built and flown, but only the fourth and final X-51A flight accomplished on 1 May 2013 was fully successful. On that flight the X-51A traveled more than 230 nautical miles in just over six minutes reaching a peak airspeed of approximately Mach 5.1 with a record-setting 210 seconds of air-breathing hypersonic flight. Overall, X-51A flight tests demonstrated the feasibility of an air-breathing scramjet-powered vehicle using hydrocarbon fuel. Flight tests showed the vehicle could successfully be boosted to reach the required conditions for scramjet engine start and the engine could sustain supersonic combustion during autonomous flight operations. The process of preparing to conduct X-51A flight tests was extremely meticulous, in part due to unique constraints of the X-51A test vehicle. This paper presents the attention to detail that was required for the proper planning and execution of X-51A flight tests., SFTE 44th International / SETP Southwest Flight Test Symposium, 28 Oct ? 1 Nov 2013, Ft Worth, TX. The original document contains color images.

Joint Operational Support Airlift Center (JOSAC)/United States Transportation Command (USTRANSCOM) long-range flight planners utilize a number of formulas and planning factors when planning missions. Air Force Pamphlet 10-1403 includes an aircraft block speeds table for USAF Major Weapons Systems and Civil Reserve Air Fleet aircraft. This table provides flight planners with a reference to quickly determine aircraft flight times between airfields based upon distance. They can use this information to plan the mission crew duty time (CDT) and flight duty periods (FDP) for each mission they plan. But currently, no aircraft block speeds table exists for Operational Support Airlift (OSA) aircraft. This research provides a method to calculate the aircraft block speeds table for JOSAC/USTRANSCOM aircraft. Evaluation of the model used in building the aircraft block speeds table requires an examination of almost 200,000 flights over the course of 5 years. A linear regression model is used to create aircraft block speeds for specific flight distances. For the given data set, each flight's distance versus average flight time is regressed, providing an equation for the average predicted distance per unit of flight time. Additionally, each flight's average speed versus distance is regressed, providing an equation for the predicted speed per unit of distance. Twenty-three different USAF OSA aircraft models are examined. These aircraft are further broken down into 13 different groups based upon aircraft cruise speed. Regression statistics are analyzed and used to determine the significance and goodness-of-fit of the model to each aircraft. Results obtained from this research provide insights into the usefulness of a JOSAC/USTRANSCOM aircraft block speeds table. Overall, the models do a good job of predicting the speed of each aircraft per unit of distance. The research shows that it makes sense to create an OSA aircraft block speeds table for long-term mission planning., The original document contains color images.

Rotary winged aviation has served the Department of Defense (DoD) and, more specifically, the U.S. Army for decades by providing airlift, service support, and attack capabilities for varying missions and combat-unique situations. To date, the payload and capabilities of helicopter platforms have been continually manipulated to obtain optimal performance and cost-effectiveness. DoD and Defense Contractors are now seeking the next level of rotorcraft development -- an increase in helicopter airspeed. An increase in airspeed is now considered one of the most important next-generation rotorcraft improvements. The challenge is to build a helicopter that can hover under load, move the required payload, and fly faster than current helicopter platforms. These improvements will allow greater service ranges, provide faster response times, and provide needed cost reductions. This paper will address the history and evolution of high-speed rotorcraft capabilities, typical roles and missions, and the advantages and disadvantages of the U.S. Army developing and procuring high-speed helicopters. Specifically, the paper will attempt to answer the following questions: (1) Are these types of aircraft practical for use in the Army inventory?, (2) What is the timeline associated with development?, and (3) Will the DoD be able to afford this capability?, Civilian Research Project.

In this thesis, a model of effectiveness for an offshore patrol vessel conducting search and rescue missions is developed and described. Beginning with a brief overview of work done by colleagues from the University of Genoa, Italy, as well as documents currently in use by the United States Navy and Coast Guard for search and rescue, this thesis explores the link between physical ship design factors and operational effectiveness by developing the Naval Postgraduate School Search (NPSS) model. The methodology included developing the NPSS search model and then using an enhanced experimental design to explore how operational noise factors, along with physical ship characteristics, affect the effectiveness of search and rescue. Operational noise factors include visibility, wind direction, distance to the last known datum, the uncertainty radius of the last known datum, and other environmental factors. Physical ship characteristics include the ship's maximum speed, the number of helicopters onboard, and the number of unmanned aerial vehicles onboard. Four metamodels are developed to show which factors have the greatest impact on the performance of the ship as a function of cumulative probability detection threshold in a search and rescue mission.

This handbook derives equations for pressure altitude, calibrated airspeed, and Mach number valid for subsonic Mach numbers in the troposphere and the stratosphere using the 1976 U.S. standard atmosphere. Equations are also developed for equivalent airspeed, true airspeed, local speed of sound, and incompressible dynamic pressure. Numerical examples are presented solving for pressure altitude, calibrated airspeed, or Mach number using the other two parameters., The original document contains color images.

This study compared the eye scan patterns of nonexperienced and experienced helicopter pilots during a simulated high-speed, low-level flight. For helicopters, flying at high speeds and low levels is not the safest way to fly, but in times of war, it is necessary for survival. Subjects were 17 active-duty Navy helicopter pilots, all of whom had different levels of flight experience based on their total flight times. Each pilot was asked to successfully navigate a course through a simulated southern California desert in a fixed-based helicopter simulator modeled after the U.S. Navy's MH-60S. The pilots' eye scanning behavior was tracked by an eye-tracking system while they flew the course to determine scan rate and locations. Flight parameters, such as air speed and altitude, were recorded by the simulator's recording system. Analysis of the results obtained from the eye tracking system showed a decreasing relationship between scan rate and pilot experience, indicating that the scan rate decreases as a pilot becomes more experienced. The analysis used altitude variance as a measure of flight performance. Results indicate that higher scan rates correlate with higher degrees of variance in the altitude, indicating that a quicker scan does not necessarily result in better performance. The more experienced pilots showed a lower degree of altitude variance overall (they were more consistent in maintaining a constant altitude above the ground), yet all of these pilots exhibited slower scan rates. The integration of eye tracking technology with a simulator representing an aircraft currently in service was a success. Although none of the null hypotheses presented were rejected, trends were evident in scan rates when compared with pilot experience. The relatively small sample size was identified as the major reason for the lack of significance of the results. Data were lost on five subjects from both the eye tracking system and the simulator's flight recording software.

A methodology is described to derive corrected True Airspeed (TAS) values for inclusion in fuel consumption calculations for Unmanned Aircraft Systems (UAS). Earlier work to develop a UAS Fuel Consumption Algorithm (FCA) relied upon default TAS values that are published in the aircraft's operations manual. Use of a default TAS in the FCA can result in fuel consumption estimations that are in error by as much as 10-20%. The TAS calculations described herein incorporate meteorological parameters that can be obtained via standard on-board instruments that are readily-available to the UAS mission commander. The step-by-step process to derive corrected TAS is explained in some detail, and a real-world example is included by which the results are verified. It is anticipated that the corrected TAS methodology will eventually be incorporated into the FCA software., The original document contains color images.

Autonomous precision placement of parafoils is challenging because of their limited control authority and sensitivity to winds. In particular, when wind speed is near the airspeed guidance is further complicated by the parafoils inability to penetrate the wind. This article specifically addresses the terminal phase and develops an approach for generating optimal trajectories in real-time based on the inverse dynamics in the virtual domain. The method results in efficient solution of a two-point boundary-value problem using only a single optimization parameter allowing the trajectory to be generated at a high rate, mitigating effects of the unknown winds. It is shown through simulation and experimental results that the proposed algorithm works well even in strong winds and is robust to sensor errors and wind uncertainty., Published in Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, v225 p336-346, 2011.

Military aircrew and other operational personnel frequently perform their duties at altitudes posing a significant hypoxia risk, often with limited access to supplemental oxygen. Despite the significant risk hypoxia poses, there are few studies relating it to primary flight performance, which is the purpose of the present study, Methods., Published in Aviation, Space, and Environmental Medicine v81 n7 p654-659 Jul 2010. The original document contains color images.

The use of bioassay cages in the efficacy assessment of pesticides, application techniques and technologies is common practice using numerous cage designs, which vary in both shape and size as well as type of mesh. The objective of this work was to examine various cage shapes and mesh types for their filtration effects on air speed, spray droplet size, and spray volume. Reductions in wind speed and droplet size seen inside the cages were measured by placing cages in a low-speed wind tunnel at air speeds of 0.5 m/ sec, 1 m/sec, 2 m/sec, and 4 m/sec and cage face orientations (relative to the air stream) of 0u, 10u, 22.5u, and 45u. Reduction in spray volume inside a select number of cages was also evaluated under similar conditions. Generally, greater air speed reductions were seen at lower external air speeds with overall reductions ranging from 30% to 88%, depending on cage type and tunnel air speed. Cages constructed with screens of lower porosities and smaller cylindrical-shaped cages tended to provide greater resistance to air flow and spray volume. Overall, spray droplet size inside the cages was minimally reduced by 0?10%. There was a 32?100% reduction in concentration of the spray volume applied relative to that recovered inside the bioassay cages depending on the cage geometry and screening material used. In general, concentration reductions were greatest at lower air speeds and for cages with lower porosity screens. As a result of this work, field researchers involved in assessing the efficacy of vector control applications will have a better understanding of the air speed and spray volume entering insect bioassay cages, relative to the amount applied, resulting in better recommended application techniques and dosage levels., Published in the Journal of the American Mosquito Control Association, v26 n4 p411-421, 2010.

A three state Kalman filter was developed to estimate the airspeed of a projectile given only measurements of its axial acceleration, along with a priori knowledge of the axial force coefficient of the projectile. The nonlinear hybrid filter was developed, tested, and tuned using simulated data and its performance on flight data was evaluated.

The EPA's proposed test plan for the validation testing of pesticide spray drift reduction technologies DRTs for row and field crops, focusing on the evaluation of ground application systems using the low-speed wind tunnel measurements and dispersion modeling, was evaluated. Relative drift reduction potential for a given DRT tested in a low-speed wind tunnel is derived from airborne droplet size measurements and airborne and deposited liquid volume measurements downwind from the spray nozzle. Measurements of droplet size and deposition data were made in a low-speed wind tunnel using standard reference nozzles. A blank emulsifiable concentration spray was applied at two different wind speeds. The wind tunnel dispersion WTDISP model was used to evaluate the drift potentials of each spray using the droplet size and spray flux measured in the wind tunnel. The specific objectives were 1. the evaluation of model accuracy by comparison of modeled downwind deposition to that measured in the wind tunnel; 2. the evaluation of drift reduction potential of the spray nozzles relative to a reference nozzle; and 3. the determination of low-speed wind tunnel data collection requirements for model input to optimize the evaluation process. The modeled deposition data did not compare well to the measured deposition data, but this was expected as the model was not meant to be used for this purpose. The tested nozzles were rated using the International Standards Organization drift classification standard. The drift ratings generally showed trends of larger droplet producing nozzles having greater drift reduction ratings. An examination of several scenarios using reduced model input requirements, which would decrease the low-speed wind tunnel data collection time, did not show any conclusive results. They suggest that further testing and refinement of the data collection process and the WTDISP model may support wider use of this system for the assessment of DRTs., Published in the Journal of ASTM International v7 n6, 2010.

There is a concerted effort within the spray application industry to develop and implement a Drift Reduction Technology (DRT) Program, which would encourage applicators to adopt technologies that are shown to mitigate off-target movement of sprays. The use of simulated or mimic sprays for atomization studies in high-speed wind tunnels allow researchers to limit the amount of active ingredients used in spray tests and facilitate the testing and certification of DRTs. However, it is important that these simulated and mimic sprays have the same physical and atomization characteristics of sprays containing active ingredients. Studies were conducted to compare droplet size generation from four spray formulations one of which was an active ingredient and three which were potential mimics and to use the collected data to examine an application management practice as a potential DRT. These sprays were atomized using two nozzles placed in high-speed airstreams in a wind tunnel and the droplet spectra measured via a laser diffraction instrument. In general, the volume median diameter (VMD) decreased by 30% to 50% as the airspeed increased. There were significant differences in droplet size between mimic sprays and those with active ingredient sprays. Results from AGDISP modeling showed increased downwind deposition with increased airspeed as a result of the increased number of finer droplets in the spray. The AGDISP results also showed differing amounts of downwind deposition at similar airspeeds from the different formulations. Downwind deposition modeling based on a simulated multi-pass spray application with reduced airspeeds near the downwind spray area border showed that the addition of the slower-speed passes near the edge can reduce total off-target movement., Published in Applied Engineering in Agriculture, v26 i1 p21-29, 2010. ISSN 0883-8542.

The stability of loads slung beneath a helicopter has been an ongoing problem. Many loads are limited by stability to speeds well below the power limited speed of the helicopter-slung-load configuration. Load motions are forced by steady and unsteady aerodynamics and are rich in complex interactions between the dynamics and aerodynamics. The present report examines the motions and aerodynamics of a cargo container and a cylindrical engine canister slung load using a flight database. The loads were instrumented with a military-grade inertial navigation unit and Global Positioning System and with sling-leg load cells to measure cable tensions. Data were collected for various load weights, sling configurations, slings suspended with and without a swivel, and for both offset and centered center of gravity in forward flight out to the limiting airspeed for all configurations. Load motions are analyzed for the directional and pendulum degrees of freedom. A variety of steady-state behaviors were found, depending on configuration. When suspended without a swivel, the cargo-container sling winds up and pendulum excursions limit operational speeds to 60 kts. With a swivel, the cargo container spun up to a steady yaw rate and the spin suppressed the pendulum motions and allowed the load to be carried to the power limit of the configuration. The spin also produced a small but measurable Magnus effect. An extreme cg offset produced stability around small end into the wind. The engine canister generally oscillated around broadside to the wind. Cable tensions and hook force are analyzed for both the swiveled and unswiveled slings. For the swiveled sling, the sling-leg tension variations occurred at harmonics of the spin rate and the harmonics were cancelled or reinforced when summed into the hook force. For the unswiveled sling, cable tension variations are dominated by the windup cycle., Prepared in collaboration with NASA Ames Research Center, Moffett Field, CA and Israel Technion Institute of Technology, Haifa, Israel. The original document contains color images. All DTIC reproductions will be in black and white.

We have been developing a computational theory of the effects of fatigue (especially sleep-related fluctuations in alertness) on the human cognitive system, implemented through mechanisms that impact existing components of the ACT-R architecture. These mechanisms include the suppression of activation in the declarative knowledge system, as well as brief breakdowns in the central production execution cycle, which we call micro-lapses. Through an iterative series of mechanistic architectural modifications, model implementations, and goodness-of-fit evaluations in task contexts like the Psychomotor Vigilance Test (PVT Dinges & Powell, 1985) and the Walter Reed Serial Addition/Subtraction Task (SAST Thorne, Genser, Sing, & Hegge, 1985), the theory has evolved to a state in which we have some confidence in its appropriateness. In other words, we feel increasingly confident that the mechanisms we are using to replicate and explain relevant empirical results are both sufficient and necessary for that purpose (Estes, 2002). This gives us a measure of confidence that it is reasonable, perhaps even advisable, to use the theory to make novel performance predictions in task contexts beyond those used for originally developing and evaluating the theory. So far, we have promising results from fatigued performance predictions in both the context of dual-tasking (Gunzelmann, Byrne, Gluck, & Moore, 2009) and also in the context of simulated driving (Gunzelmann, Moore, Salvucci, & Gluck, submitted)., See also ADA540044. Presented at the International Conference on Cognitive Modeling (9th) (ICCM 2009) held in Manchester, United Kingdom, on July 23-26, 2009. U.S. Government or Federal Purpose Rights License. The original document contains color images.

The EPA's proposed Drift Reduction Technology DRT low-speed wind tunnel evaluation protocol was tested across a series of modified ASAE reference nozzles. Both droplet size and deposition and flux volume measurements were made downwind from the nozzles operating in the tunnel at airspeeds of 1 m/s and 2.5 m/s, following the prescribed protocol. Overall, the data followed anticipated trends with a few unanticipated results observed, which could be addressed in future iterations of the protocol. There were some difficulties meeting the proposed protocol data quality requirements. Refined quality requirements would address this with no detrimental effect to the overall data set. Major concerns, at this point, are the feasibility of the overall protocol as well as the applicability of the final collected data. The protocol was tailored such that the collected data would directly input into a dispersion model most likely WTDISP. However, not having access to such a model puts into question the validity and practicality of the protocol in its present form. Given the time requirements, which require approximately nine times that of the high speed protocol 90 min versus 10 min, unpublished data, there is a definite need to modify the existing protocol to insure equitable implementation of the overall DRT program., Published in the Journal of the ASTM International v6 n4 (JAI 102129).

The U.S. Environmental Protection Agency EPA has initiated the development of protocols for measuring spray drift reduction technologies (DRTs) related to the application of agricultural protection chemicals. The DRT Program is an EPA-led initiative program to "achieve improved environmental and human health protection through drift reduction by accelerating the acceptance and use of improved and cost-effective application technologies." The first step in implementing the DRT program is to develop a set of protocols, standard operating procedures, and data quality assurance steps so that the results from any trials or research conducted are scientifically valid and repeatable. A protocol for measuring spray droplet spectra via laser diffraction equipment in a high speed wind tunnel (air velocities > 160 kph (100 mph)) was tested. Following the proposed protocol, five reference nozzles were evaluated with spray solutions of deionized water, water + 9 % isopropanol, and water + 0.25 % of a nonionic surfactant. Each of the nozzle and spray solution combinations were evaluated in 160, 193, and 225 kph (100, 120, and 140 mph) airstreams, as well as under static (0 kph) conditions. The results of these atomization studies showed that there were significant differences in droplet spectra between the spray solutions and from the different air velocities. Based on the time to complete the tests, the author suggest using a +/- 5 % standard deviation values as criteria for accepting atomization tests results., Published in the Journal of ASTM International, v6 n4 Paper JAI102122, Apr 2009; published online March 2009.

AIRSpeed, Naval Enterprise's integration of Theory of Constraints1, Lean2, and Six Sigma3 has been implemented at the intermediate4 and depot-level maintenance5 activities across Naval Aviation.6 Although these process improvement tools have proven successful in civilian corporations, the results at military installations have been mixed. To achieve success at the operational level, AIRSpeed implementation requires command buy-in, fleet-wide metrics, dedicated manpower, robust training, and change agent incentives.

In 2007 the Deputy Commandant for Aviation signed the new AVPLAN, which stated "The vision of aviation logistics in the future is flexible, agile, and reliable support to the ACE with a lighter/smaller logistics footprint and accompanied by proactive decision-making approaches and tools." To support this new vision for aviation logistics, a new set of tools is required. These tools must be integrated, flexible, adaptable, and technologically advanced. They must operate using industry standard commercial off-the-shelf hardware, software, and operating systems. The tools must be designed from the ground-up to support decision making and automation. To attain Lt. General Castellaw's vision, the Marine Corps aviation logistics community must develop an upgraded and integrated C2 system to support future aviation logistics requirements., EWS Contemporary Issues Paper.

A low air speed, spray dispersion tunnel was constructed and used to evaluate the collection efficiency of passive spray flux collectors. The dispersion tunnel utilizes an air-assisted nozzle to generate a spray cloud with a D(sub V0.5) of 18.5 (+/-0.4)micrometers at air speeds ranging from 0.4-4.0 m/s. A sampling protocol was developed to minimize spray flux and air speed variation effects while providing a check on theoretical collection efficiency calculations. A soda straw and monofilament line was placed on either side of a nylon screen cylinder collector, and all three were positioned in the center of the tunnel's cross-sectional area. Twelve replicated trials were conducted at air speeds of 0.4, 1.3, 2, and 3.8 m/s. Droplet size was measured every replication using a Sympatec HELOS laser diffraction system. Using theoretical collection efficiencies for cylinders and the measured fractional droplet size, the actual flux was estimated from the volume of spray collected on the soda straw and monofilament samplers and used to determine the collection efficiency of the nylon screen cylinder. Collection efficiency increased with air speed for all collectors and results ranged from 5 to 40 % for the soda straws, 46 to 83 % for the monofilament line, and 9 to 98 % for the nylon screen cylinders. Collection efficiency data are crucial to the evaluation of field collected data from aerial application research studies with respect to mass accountability and comparisons to other studies and drift model results., Presented at the ASTM Symposium on Pesticide Formulations and Delivery Systems (28th), held in Tampa, Florida on 30 October-1 November 2007. Published in Journal of ASTM International, v5 n1 p1-10, January 2008.

There has been much debate over the future of medium lift for the Marine Corps. With the service life of the CH-46E coming to an end, the Marine Corps needed to find a replacement. As technology progressed, a tiltrotor aircraft seemed like an ideal solution. The Marine Corps pursued that option, resulting in the MV-22 Osprey. Over the years, the Osprey program has generated much criticism. Skeptics argued about the safety of the aircraft and maintenance program, and now that the Osprey has achieved its initial operational capability (IOC), the main concern is whether or not the Osprey will be able to fulfill the role of the aircraft it is replacing. A common view exists that the Osprey will be unable to complete all the missions of the CH-46E, thus resulting in a capabilities gap. The major concerns for this capabilities gap revolve around five main issues: escort for the Osprey, the casualty evacuation (CASEVAC) mission, self-defense, landing zone (LZ) criteria, and shipboard operations. However, as technology continues to increase, and tactics, techniques, and procedures (TTPs) continue to be developed and refined, the Osprey is not only capable of accomplishing all of the missions of the CH-46E, but it will also bring an increase in capabilities not available with the CH-46E., EWS Contemporary Issues Paper.

A low air speed, spray dispersion tunnel was constructed and used to evaluate the collection efficiency of passive spray flux collectors. The dispersion tunnel utilizes an air-assisted nozzle to generate a spray cloud with a D(V0.5) of 18.5 (+/- 0.4 microns) at air speeds ranging from 0.4?4.0 m/s. A sampling protocol was developed to minimize spray flux and air speed variation effects while providing a check on theoretical collection efficiency calculations. A soda straw and monofilament line was placed on either side of a nylon screen cylinder collector, and all three were positioned in the center of the tunnel's cross-sectional area. Twelve replicated trials were conducted at air speeds of 0.4, 1.3, 2, and 3.8 m/s. Droplet size was measured every replication using a Sympatec HELOS laser diffraction system. Using theoretical collection efficiencies for cylinders and the measured fractional droplet size, the actual flux was estimated from the volume of spray collected on the soda straw and monofilament samplers and used to determine the collection efficiency of the nylon screen cylinder. Collection efficiency increased with air speed for all collectors and results ranged from 5 to 40% for the soda straws, 46 to 83% for the monofilament line, and 9 to 98% for the nylon screen cylinders. Collection efficiency data are crucial to the evaluation of field collected data from aerial application research studies with respect to mass accountability and comparisons to other studies and drift model results., Published in Jnl. of ASTM International, v5 n1 p1-10, Jan 2008.

The purpose of this research was to investigate a method of determining an aircraft's airspeed in the event of total air data system failure. The process combined GPS-aided inertial velocity with a continuously estimated wind velocity. A velocity estimator (VEST) algorithm was developed to combine the inertial and wind velocities to provide an estimate of the aircraft's current true velocity to be used for command path gain scheduling and for display in the cockpit. The effort resulted in a flight test program as part of a Test Management Project at the United States Air Force Test Pilot School. The project consisted of two ground test and six flight test evaluation sorties. The average true airspeed error from the estimator algorithm during inflight maneuvers was determined to be 12 knots, nondivergent, and minimally variable. The results of this research clearly showed the potential of the algorithm to determine an aircraft's airspeed in the event of an air data system failure. Recommendations for future research and improvements to the operation of the velocity estimator algorithm are discussed., The original document contains color images.

This Test Operations Procedure (TOP) describes the test requirements, objectives, responsibilities, and techniques/methodologies required to perform pitot-static system calibrations. This TOP is used for rotary-wing and fixed-wing aircraft. The TOP will facilitate test planning, execution, and data collection using two techniques (trailing device and pace) and the equipment required to complete pitot-static system calibrations. Variations in platform requirements are discussed within this TOP. These guidelines, along with platform specific capabilities and requirements, will enable the tester to develop a comprehensive testing strategy., The original document contains color images.

Air movement can provide comfort in warm environments in energy-efficient and cost-effective ways. However, there have been suggestions that people’s perception of air quality reduces with increased air temperature, which could preclude the air-movement approach to comfort control. We examined this issue in a human subject test in neutral (24.5ºC) to warm (28ºC, 30ºC) temperatures, with a range of air speeds provided from two sides into the face and breathing zone. Perceived air quality (PAQ) was significantly improved by airspeed. At 28ºC, re-circulated room air at 1 m/s airspeed produced PAQ equivalent to that found under the neutral condition. Mechanisms of how air movement affects PAQ are discussed. In warm environments, air movement can provide high levels of both thermal comfort and perceived air quality.

This report presents the results of Project Have VEST, a limited evaluation of a back up velocity estimate following air data system failure. This test program demonstrated the potential of the VEST algorithm to provide an airspeed estimate using aircraft last known state and flight control computer accelerations and rates. The USAF Test Pilot School (TPS), Class 07A, conducted six flight tests totaling 11.3 hours at Edwards AFB, California, from 9 to 21 Sep 2007. All test objectives were met., The original document contains color images.

Recognizing the need to reduce cost, Naval Air Systems Command (NAVAIR) reorganized the Intermediate and Depot level maintenance structures to form the combined Fleet Readiness Center. By combining Intermediate and Depot facilities, NAVAIR can reduce Aviation Depot Level Repairable (AVDLR) costs by interdicting Beyond Capable Maintenance AVDLR's. NAVAIR further consolidated the Naval Aviation Enterprise by creating Centers of Excellence (COE) at designated FRC's to limit the amount of repair sites for particular Weapon Repairable Assemblies. The purpose of this MBA Project is to demonstrate that the COE decreases turn-around-time and drastically reduces AVDLR costs by interdicting BCM AVDLR's. This project provides a comprehensive overview of efficiencies and cost savings gained by FRC West's APG-65/73 radar system COE. This project utilizes Arena Software creating a model that better quantifies the benefits of the COE maintenance structure. In addition to demonstrating efficiencies, this project highlights potential detractors that could cause the COE to fall short of its intended goals of better efficiency and cost savings realization. This project was sponsored by FRC West, located in Lemoore, CA. The results identified by this project focus on FRC West, however, they can be generalized and be made applicable throughout the Naval Aviation Enterprise., The original document contains color images.

Naval Aviation, faced with budgetary pressures, decreasing buying power and increasing costs of aircraft and equipment, realized it had to change the way it did business in order to recapitalize. The Naval Aviation Enterprise (NAE) was formed to implement the aviation components of Sea Power 21 and Sea Enterprise, including modernization and recapitalization. Through the implementation of AIRSpeed, the NAE strives to provide the right amount of readiness at the right cost, so that money can be saved and returned to the Navy and Marine Corps to recapitalize the Fleet. This thesis examines the NAE's effort to generate measurable cost savings toward recapitalization. The background and implementation of AIRSpeed are reviewed. It identifies cost savings attributed to AIRSpeed initiatives and investigates the relationship between costs savings and reinvestment and recapitalization. The results of this thesis reveal that the NAE is achieving measurable cost savings, but the cost saving has not been made available for recapitalization. The thesis reveals some identifiable organizational challenges and change issues that inhibit the achievement of NAE s goals. These findings are used to develop and present a series of recommendations to assist the leadership to further align AIRSpeed programs with the recapitalization vision., The original document contains color images.

This research was done as part of an effort to develop alternative fire suppressant technologies for aircraft engine nacelles. A circular cylinder array was designed, built, and placed in the AFIT roll-around low speed wind tunnel to model generic clutter inside an engine nacelle. A turbulence grid was fabricated to enable measurements of the effects of turbulence level, independent of airspeed, on the flow over different model configurations. The wind tunnel test section was 12 inches wide x 12 inches high x 24 inches long. Pressure differential measurements were taken on various cylinder configurations. The configurations included one cylinder as well as one, two, and three arrays of cylinders. Half diameter spacing was used for two and three cylinder cases, as well as an additional case at a two-diameter spacing with the three array configuration. All conditions were tested with and without the turbulence grid placed at the front of the test section. Pressure differential measurements were taken at 15-degree increments from 0 degrees - 180 degrees on the circumference of an upstream cylinder, centered vertically on the array. Hot-wire measurements were taken with and without the turbulence grid to determine airspeed and the effect of turbulence intensity generated by the grid on the wake profile. Also, vertical traverse data was taken with the hot-wire to determine airflow characteristics behind two configurations, both with and without a turbulence grid. The first had only one cylinder installed while the second was done with three arrays spaced at a half-diameter length. Pressure and velocity measurements were used to investigate the effects caused by the upstream turbulence grid., The original document contains color images.

"The use of heavy lift rotor craft to vertically envelop the adversary with the future combat system force package has shown significant promise in war games and simulation models." However, the U.S. Army currently lacks a heavy lift rotor craft that is capable of transporting assets throughout the depth of the battlefield. "The objective of the Deep Battle Concept is to limit freedom of action of the enemy commander and to disrupt the coherence and tempo of his operations." The Army's current aviation assets cannot support the Deep Battle Concept and must be augmented by the V-22 to remain dominant in future conflicts. If the Army is to maintain its force projection capability and continue with its envisioned goals for the Future Combat System (FCS) and sea-basing, it needs to acquire the V-22 and research a quad-tilt version of the V-22. The V-22's operational capabilities will enhance the Army's operational readiness and relevance and continue to press the envelope of the Army's transformation process., EWS Contemporary Issues Paper.

The goal of this project was to determine how to decrease the F414 engine throughput time at the Aircraft intermediate Maintenance Division (AIMD) at Naval Air Station (NAS) Lemoore, California. To achieve this goal, organizational modeling was employed to evaluate how changes to the organizational structure of the Lemoore AIMD affected engine throughput time. Data collected to build the organizational model was acquired via interviews with AIMD personnel. A baseline model of the AIMD organization was developed for the purpose of modeling the organization s current structure and performance. The actual, real-world, duration required to conduct F414 maintenance was compared to the duration predicted by the model and determined to be within 3%. Once confidence was gained that the baseline model accurately depicted the organization s actual F414 maintenance performance, modifications or interventions to the model were made to evaluate how organizational changes would affect F414 maintenance duration. Interventions included paralleling the tasks associated with accomplishing administrative paperwork when initially receiving the F414 engine, and tasks associated with on-engine maintenance, combining personnel positions, adding personnel, and modifying the duration and frequency of meetings. The modeled results of these modifications indicated that the paralleling effort significantly decreased the F414 maintenance duration; likewise, decreasing meeting frequency and slightly increasing duration also facilitated a decreased duration., The original document contains color images.

This project focuses on the J52-P408 engine repair process and the implementation of the "AIRSpeed" program at the Aircraft Intermediate Maintenance Department (AIMD) at Naval Air Station Whidbey Island (NASWI), WA. The project was conducted with the sponsorship and assistance of Program Executive Office Ships (PEO SHIPS) and Program Executive Office Integrated Warfare Systems (PEO IWS). The goal of this project is to analyze how the leadership of AIMD incorporated Theory of Constraints (TOC), Just in Time (JIT), Lean, Six-Sigma, and Lean-Six-Sigma methodologies in the engine repair process, and examine the effects of its application in relation to repair cycle time and overall readiness level. This report will describe and compare the earlier and the current AIRSpeed engine removal and repair processes, starting from the flight line to the ready for issue (RFI) pool at AIMD. Using simulation modeling tools and private industry production and inventory management philosophies, we will make recommendations for further improvement in the repair process. We will examine how the application of AIRSpeed processes contributes to the mission readiness of the United States Navy and Marine Corps fleet of EA-6B Prowler aircraft, while reducing operation and maintenance cost., The original document contains color images.

This thesis further defines the position of greatest fuel savings benefit for the trail aircraft flying in a two-ship formation. The HASC95 vortex lattice code was used for the examination. Investigations of a similar formation of F-16 aircraft and a dissimilar formation of a lead KC-135 aircraft and a trail F-16 aircraft were conducted. The analyses determined the effects of varying airspeed on the optimal position. In addition, flight control surface deflections were taken into account during the analyses. Both investigations trimmed the aircraft in the yaw and roll axes to determine the optimal savings. The similar analysis was conducted at an altitude of 20,000 feet and three airspeeds: cruise speed of 300 knots, maximum range airspeed of 271 knots, and maximum endurance airspeed of 211 knots. The savings for the trail aircraft were determined to be 16%, 21%, and 34%, respectively, at a constant wing tip overlap of 13.5% of the wingspan. The dissimilar formation was completed at an altitude of 20,000 feet and 300 knots airspeed. This resulted in a 26% savings for the trail aircraft with a wing tip overlap of 16.7% of its wingspan. A flight test was flown for the similar formation profile of F-16s. The flight test investigated the change in vertical positioning and lateral spacing from the first analysis and captured data at 300 knots. The results of the flight test were inconclusive. However, the determined area of apparent savings was bounded by 7.9% to 19.9% wing tip overlap and -3.2% to -7.3% vertical separation. At the bounds, fuel savings of 12% and 13% +/-7% were observed. The drag savings profile had the capability to increase the range of existing airframes, providing the benefit at no cost. The analytical study was conducted at the Air Force Institute of Technology, Wright-Patterson AFB. The flight test was conducted at the U.S. Air Force Test Pilot School, Edwards AFB, California., The original document contains color images.

The tilt-rotor V-22 Osprey represents a remarkable increase in capability and can perform functions requiring speed and range that are well beyond the physical and aerodynamic capabilities of traditional helicopters. However, it will operate differently from current assets due to its size and non-traditional design. Given these differences, can the V-22 assume the missions assigned to the CH-46 and is the loss of capabilities sufficient to warrant a traditional medium lift helicopter to augmenting the V-22? Additionally, the V-22 is 10 years behind schedule and the CH-46 and CH-53D must continue to play a substantial role in the medium lift mission for at least the next 10 years. What is the best mix of these assets to carry out the medium lift mission until fielding of replacement aircraft is complete? Movement of troops within the battle space is the primary role of medium lift assets. The Osprey represents a substantial leap in technology and capability and has the potential to transform assault support operations. However, it is wider than the CH-53E Super Stallion, making it the widest helicopter in the fleet. Additionally, The V-22 presents concerns for escort operations. Neither the AH-1 Cobra, F/A-18 Hornet or AV-8 Harrier, have the endurance to support the V-22, and thus escort support of the V-22 will require multiple sorties. Furthermore, the aerodynamic limits of external loads, generally 130 knots or less, negate the air speed benefit of the V-22 when carrying such cargo. Finally, the current production V-22 costs over $70 million per airframe and because of its complicated design, maintenance costs are higher than expected. The Marine Corps has pursued the Osprey for more than twenty years and since the decision to procure the V-22 was made, new and more advanced, traditional helicopters such as the US-101 and S-92, have been developed and are currently in service around the world.

The Air Force has expressed interest in developing a bomber variant of the F/A-22 Raptor to "bridge the gap" between today's bombers and a follow-on bomber in 2037. Questions exist regarding the FB-22's feasibility, cost, and combat potential. In 2002 it was reported that Lockheed Martin Corp. had begun studying a radically modified version of the Raptor called the FB-22 . This variant would seek to significantly increase the F/A-22's air-to-ground capabilities, primarily through a redesign that would double the aircraft's range and significantly increase the aircraft's internal payload. Some estimate that the delta-winged FB-22 could carry up to 30 of the developmental 250-lb. Small Diameter Bombs. These potential improvements would likely result in some performance tradeoffs, such as reduced acceleration, speed, and maneuverability. Although not officially part of the F/A-22 program, and still in the conceptual phase, the FB-22 idea has elicited enthusiasm from some Air Force leaders. Air Force Secretary James Roche reportedly favors the FB-22 as the potential platform of choice for providing better close air support for tomorrow's ground forces. Air Force leaders have also depicted the FB-22 as a medium-range bomber that could serve as a "bridge" between the current bomber force and a follow-on capability to be fielded in the 2037 time-frame. On April 29, 2004, the Air Force issued to industry a "request for information" on resources and technologies that might contribute to a regional, or interim bomber. Other officials have reportedly shown less interest in the FB-22. Air Force acquisition chief Marvin Sambur said that the F/A-22's developmental difficulties would have to be solved before the FB-22 could be considered. Potential costs and schedule of the FB-22 concept are still quite notional. How this multi-role aircraft would compete with -- or conversely complement -- the F-35 Joint Strike Fighter has not yet been determined., CRS Report for Congress.

DSTO operates a low speed wind tunnel within the Air Vehicles Division of the Platforms Sciences Laboratory. Airspeeds up to approximately 100 m/s can be produced in the empty test section which is 2.7 m wide by 2.1 m high. Realtime display of acquired test data from the wind tunnel is important for providing feedback to the project manager and test engineer. A software package called DSPFRC was developed for this purpose, giving a graphical display of the force and moment coefficients. This document provides details of the software and its operation. It also provides information on programming and development considerations of the software.

The type of research that investigates operational tasks such as flying an aircraft or flight simulator is extremely useful to the Air Force's operational community because the results apply directly to "real-world" settings. However, the task of collecting, processing, and analyzing flight data involves handling a tremendous amount of information; therefore, it is vital to develop a precise methodology in order to successfully evaluate measures of pilot performance. A defined methodology was developed and implemented in the evaluation of flight data collected from the Link F-117A Weapon System Training Simulator during a fatigue study at Holloman Air Force Base, New Mexico. The steps involved in processing the flight data, including data collection, reduction, and analysis, are described in this paper. This methodology enabled the first ever objective quantification of fatigue effects on Air Force fighter pilots. The procedure revealed that the fatigue from 20 or more hours of sleep loss significantly impacted objectively measured basic piloting skills, including the ability to maintain headings, altitudes, airspeeds, etc. Fatigue affected some maneuvers more than others. This flight scoring methodology can be applied to digitized flight data collected from both simulators and aircraft in order to objectively measure the effects of stressors and interventions on flight performance., The original document contains color images.

This article presents the accomplishments of the flight testing of C-130H air and ground minimum control speeds (Vmca/Vmcg). Testing was requested by Air Mobility Command and the C-130 System Program Office (SPO). Testing was conducted in accordance with test plan AFFTC-03-39, C-130H GROUND- AND AIR-MINIMUM CONTROL SPEED AND AIRCRAFT AERODYNAMIC MODELING DETERMINATION TESTING, on C-130H aircraft, USAF serial number 96-7322, from 12 January to 9 April 2004 and was comprised of 11 ground tests, 30 flights, and 71 flight test hours. The responsible test organization was the 412th Test Wing of the Air Force Flight Test Center, Edwards AFB, California. The test execution organization was the Global Reach Combined Test Force, Edwards AFB. The overall test objective was to determine the ground and air minimum control speeds for the C-130H aircraft. Test objective was met ahead of schedule using innovative fight testing techniques., The original document contains color images.

Document contains specifications on aircraft structure, launch mechanisms, and recovery configurations. included are the advantages of an unmanned combat air vehicle plus the challenging concerns surrounding it., See also ADM001685. Presented at the Proceedings for Aerodynamic Issues of Unmanned Air Vehicles (UAV), held in University of Bath, United Kingdom, 4-5 Nov 2002. The original document contains color images.

This study analyzes the impact of unmanned aerial vehicle (UAV) capabilities on intelligence gathering missions for a Marine Expeditionary Brigade (MEB) commander in 2015. The Marine Corps Warfighting Lab (MCWL) is developing requirements for an intelligence, surveillance, and reconnaissance (ISR) UAV that supports rapid planning and decision making for multiple concurrent operations and facilitates maneuver and precision engagement. The acquisition of a 2008 Pioneer replacement also is underway at Marine Corps Systems Command (MARCORSYSCOM). However, the importance of various capabilities for this replacement UAV presently lacks quantitative analysis. Through modeling, agent-based simulation, and data mining, this study explores the validity of current requirements and provides insights into the importance of various UAV characteristics, such as airspeed, endurance, sweep width, and sensor capability. Each year, the Navy/Marine Corps conducts Fleet Battle Experiment Sea Viking in Southern California. The primary objective is Command and Control and ISR development. This study looks at UAV operations in the Sea Viking scenario provided by MCWL in the MANA agent-based modeling environment utilizing robust design, Latin hypercubes, data farming techniques, the Maui High Performance Computing Center, and the JMP Statistical Discovery Software package. The Sea Viking Experiment, the Marine Corps' largest annual experiment, provides a credible scenario for model development. The advantages of tactical routing, a 7 hour (or greater) on-station time, a minimum 4,500 meter sweep width, and a probability of classification of at least 0.4 are verified for the Sea Viking scenario. This analysis indicates that a UAV in this scenario does not need to travel in excess of 200 knots. The results have design consequences for MCWL's Sea Viking 20XX and provide key parameters for physics-based simulations such as COMBAT XXI. A 15-item bibliography is included. (26 figures, 26 refs7, The original document contains color images.

Due to the destructive nature of flutter, flutter testing is a mandatory requirement for certification of both civilian and military aircraft. However, along with the complexity of newer aircraft, the time and cost associated with flutter testing has increased dramatically. Considering that many of the test techniques and analysis methods used to perform flutter testing date back to the 1950s and 1960's it may be time to take a fresh look at how flutter testing can best be accomplished. This thesis revisits flutter testing techniques and proposes an alternative to traditional flutter testing. The alternative uses flight test data from an aircraft that is performing an acceleration to clear the flutter envelope of the aircraft. Four academic issues arise from this new test approach. 1) Are frequencies and damping affected by the acceleration of the aircraft? 2) Can parameter identification algorithms extract frequency and damping values from the time varying data? 3) Can the vibration response at airspeeds (or Mach numbers) beyond which the aircraft has accelerated be anticipated? 4) What formal criteria can be used to determine when the aircraft needs to end the acceleration and terminate the test point? The academic contribution of this thesis is to address these issues. It is shown that although the frequencies and damping values do change the change is so small that it is irrelevant. It is also shown that by taking small windows of data, within which the change in parameters is small, it is possible to accurately identify parameters from the time varying data. Finally it is shown that at least in principal parameters can be predicted using data from sub-critical airspeeds, and that testing can be discontinued before an unstable flight condition is reached.

This project analyzes the effect of transverse shear deformation upon the aeroelastic response of composite wings in high speed flow regimes. Previously, models were developed to predict the aeroelastic characteristics of classical materials in high speed flow. However, these studies ignored transverse shear by assuming an infinite modulus of rigidity. This assumption underestimates transverse flexibility by ignoring the transfer of loads through the wing thickness. By assuming a finite modulus of rigidity and redeveloping the governing equations, this model would more accurately predict the aeroelastic response of composite wings. This analysis concerns mainly the determination of aeroelastic trends versus more detailed solutions. Thus, linearized flow theory is used. Initially, this research focused on analyzing the aeroelastic effects of compressibility and transverse shear deformation with the thought that the findings could be used to design high-performance aircraft. However, the results have shown that transverse shear is a larger problem at low air speeds than at high air speeds. Every analysis from the effect of transverse shear flexibility to wing thickness showed that the wing properties common in general aviation aircraft led to larger variations in aerodynamic performance. The results also showed that as Mach number increases, the critical air speeds in both steady and unsteady flow decrease, and the compressible analysis varies from incompressible analysis by anywhere from 0-30% in standard atmospheric conditions. Upon conclusion, the study gives results for divergence speed and flutter speeds, as well as their mode shapes. (8 tables, 16 figures, 12 refs.), The original document contains color images.

The windblast test facility at Dayton T. Brown (DTB) was recently reconstructed with several modifications. These modifications were aimed at improving airflow uniformity and increasing the effective blast area. AFRL has routinely used the facility at DTB in its research programs and collaborated with DTB on the evaluation of the facility upgrades. Fifty-two windblast tests were conducted with airspeeds ranging from 375-725 Knots Equivalent Airspeed (KEAS). During these tests the flow at the location of where test articles would be placed was measured. The resulting flow was used to calculate the velocity decay from the windblast nozzle to the test article as well as determine the airflow uniformity across the test article space. It was determined that the airflow was uniform and the system was capable of producing a 700 KEAS blast.