A Basic Flight Simulation Tool for Rigid Airships
This technical report (NLR-TP-2000-443) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2000 and was written by A.J.J. Lemmers and A.P.L.A. Marsman. The National Aerospace Laboratory NLR is developing a basic flight simulation tool of a rigid airship. This tool will allow simulation of a generic large rigid airship and it will support the fundamentals of Flight Mechanics and Stability and Control. The tool will run in a PC-based environment using MATLAB/Simulink. The basic simulation will support six degrees of freedom and will cover the complete flight envelope. A modular approach is used for the design, which gives the possibility for an easy upgrade when new or modified data is available. [Taken from abstract]. The full text is available as a PDF file.
A Comparison of Nonlinear Algorithms to Prevent Pilot-Induced Oscillations Caused by Actuator Rate Limiting
This is a full text thesis by James G. Hanley which was presented to the Air Force Institute of Technology (AFIT) in 2003. Actuator rate limiting has contributed to Pilot-Induced Oscillations (PIO) on almost every new fly-by-wire aircraft. Actuator rate limiting affected aircraft handling qualities in two ways: it exposed the aircraft’s unaugmented flight dynamics and shifted the phase between the pilot input and actuator output. Phase shifting was the primary cause of PIO due to rate limiting. Two proposed solutions both placed a flight control system filter between the pilot command and actuator input. The first, referred to as Feedback-with- Bypass (FWB) and developed by Dr. Lars Rundqwist of SAAB Aircraft, used a low-pass filter to add phase lead to the pilot command. The second, referred to as Derivative- Switching (DS) and developed by Dr. Brad Liebst and Capt. Mike Chapa of AFIT, used the first and second derivatives of the pilot’s command to reverse the actuator output in phase with the pilot input during actuator rate limiting. The objective of this study was to compare the ability of these two flight control system filters to prevent PIO during actuator rate limiting, and the filters’ effects on aircraft handling qualities. This comparison was conducted in three steps: computer simulation, ground simulation in the Large Amplitude Multimode Aerospace Research Simulator (LAMARS), and flight tests conducted in the Variable Stability In-flight Simulator Test Aircraft (VISTA). Pilot PIO and Cooper-Harper ratings were used for the comparison during the last two steps. During computer simulation, the FWB filter better reduced the phase lag and prevented sustained or divergent oscillations during the closed-loop analysis. During both ground simulation and flight tests, the FWB filter was more effective at preventing divergent PIO and improving handling qualities. This was primarily due to the ability of the FWB filter to reduce phase lag better than the DS filter. However, PIO could not be prevented by either filter for configurations with poor aircraft dynamics and low actuator rate limits. Overall the FWB filter performed better during all test. [Taken from abstract] The full text of the thesis is available in PDF formate and is provided by the Air University ResearchWeb site.
A Design of Fault Tolerant Flight Control Systems for Sensor and Actuator failures Using On-Line Learning Neural Networks
This web site provides access to a West Virginia University Department of Mechanical and Aerospace Engineering PhD dissertation, by Younghwan An, dated 16 November 1998. The thesis examines the performance of a neural network-based fault tolerant system within a flight control system, which integrates sensor and actuator failure detection, identification, and accommodation (SFDIA and AFDIA). In particular it focuses on improvements to the performance of the SFDIA scheme in the presence of ramp-type soft failures which are hard to detect as well as the achievement of an efficient integration between SFDIA and AFDIA without degradation of performance in terms of false alarm rates and incorrect failure identification. Bibliographic and abstract details are available in HTML format. The full text of the document is accessible online in PDF format This title is part of West Virginia University’s Electronic Thesis and Dissertation Project
A History of Suction-Type Laminar-Flow Control with Emphasis on Flight Research
This web site provides access to a NASA Dryden Flight Research Center history series publication, by Albert L. Braslow. It presents a history of suction-type laminar-flow-control research, and in particular describes the contribution made by NACA and NASA in this field. It covers early progress, as well as the principal problems that inhibited the attainment of laminar flow with either passive or active laminar-flow control. It also describes the resurgence of laminar flow control research at NASA after 1975, with a particular emphasis on the flight-research programme. The book concludes with a summary of the status of laminar-flow control technology in the mid-1990s. The full text is available online in HTML format.
A Method to Derive the Usage of Hydraulic Actuators from Flight Data
This technical report (NLR-TP-2002-589) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2002 and was written by H. Kannemans and H.W. Jentink. The quantification and prediction of the health status of aircraft are challenging aspects of Prognostics and Health Management (PHM). The Dutch PHM Consortium (DPC) develops concepts for prognostics and health management of aircraft. Within this framework there is a need to know the operation of the hydraulic system in flight. Usage data can be derived from data measured with dedicated sensors, but to keep aircraft weight, sensor failures and costs as low as possible there is a requirement to minimise the number of such sensors. Therefore a technique is developed to derive information about the operation of the hydraulic system from parameters measured during the flight for general purposes, the recorded flight data. Condition Parameters and Remaining Life Time of components can be derived with the technique. The force produced by the hydraulics and the displacements of the piston, being representative parameters for wear, can be calculated from flight data and an aerodynamic model of the aircraft. In terms of flight mechanics the actuator displacement and force on the actuator are directly related to control surface deflection and hinge moment. These two parameters are calculated applying flight simulation models and flight data. The technique and some results for the RNLAF (Royal Netherlands Air Force) F-16 are presented. [Taken from abstract]. The full text is available as a PDF file.
A Non-Linear Aeroelastic Model for the Study of Flapping-Wing Flight
This is a University of Toronto, Institute for Aerospace Studies PhD thesis, by Rambod Fayaz Larijani, dated 2000. non-linear aeroelastic model for the study of flapping-wing flight is presented. This model has been developed to simulate the fully stalled and attached aerodynamic behaviour of a flapping wing and can account for any forcing function. An implicit unconditionally-stable time-marching method known as the Newmark method is used to accurately model the non-linear stalled and attached flow regimes. An iteration procedure is performed at each time step to eliminate any errors associated with the temporal discretization process. A finite element formulation is used to model the elastic behaviour of the wing which is composed of a leading edge composite spar and light-weight rigid ribs covered with fabric. A viscous damping model is used to simulate the structural damping of the wing. The Newmark code generates instantaneous lift and thrust values as well as torsional and bending moments along the wing span Bibliographic and abstract details are available in HTML format. The full text of the thesis is accessible online in PDF format. This title is part of Library and Archives (LAC) Canada's theses collection. Access is provided via the Theses Canada Portal
A Study in Drag Reduction of Close Formation Flight Accounting for Flight Control Trim Positions and Dissimilar Formations
This is the full text of a Master's thesis by Major Michael T. Morgan, USAF, AFIT/GAE/ENY/05-M13, which was presented to the Faculty Department of Aeronautics and Astronautics of Air University's Air Force Institute of Technology (AFIT), in March 2005. 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. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Active Control Technology for Enhanced Performance Operational Capabilities of Military Aircraft, Land Vehicles and Sea Vehicles
This site provides access to a Research and Technology Organization Meeting Proceedings, RTO-MP-051, Paris, June 2001. The document contains papers presented at the Symposium of the RTO Applied Vehicle Technology Panel (AVT) held in Braunschweig, Germany, 8-11 May 2000. The Symposium analysed the potential of active control technology for the performance demands of future vehicles and engines, in particular high manoeuvrability, lower specific fuel consumption, higher power-to-weight ratios and lower life-cycle cost. Performance, stability, control, fluid dynamics, structural and engine layout questions were dealt with in 5 keynotes and 77 papers. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (126Mbytes) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Adaptive and Reconfigurable Flight Control
The site provides access to an Air University, Air Force Institute of Technology, Graduate School of Engineering and Management, PhD dissertation, by Lt Col. Yih-Shiun Huang, AFIT/DS/ENG/01-02, dated March 2001. The thesis describes the development of an indirect adaptive and reconfigurable flight control system consisting of; a system identification module, a parameter estimate smoother, and a proportional and integral compensator for tracking control. Citation details and an abstract are available in HTML format. The full text can be accessed in PDF format. The document is part of the Air University Research Database
Advanced Aeroservoelastic Testing and Data Analysis
This is Research and Technology Organization (RTO) AGARD Conference Proceedings report, AGARD-CP-566, dated November 1995. The papers presented at the AGARD Structures and Materials Panel's Specialists' Meeting on Aeroservo elastic Testing and Data Analysis, held in Rotterd am in May 1995 are included. Flutter is a potentia lly catastrophic aeroelastic dynamic instability. Flight flutter tests are conducted to demonstrate freedom from flutter for critical aircraft conditi ons and to derive data to validate the flutter ana lysis. Active control systems (ride control, gust load alleviation, flutter stabilization, etc.) add to the scope and complexity of these tests in tha t control system instability due to aeroservoelast ic interactions must also be considered. The concl usions of the meeting are that most of the tests n eed improvements, some tests should be better expl oited, and at least one test, the in-flight measur ement of unsteady air loads, should become standar d practice to close a gap in the logic of flutter certification. For individual titles, see N96-24338 through N96-24358. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (78 Kb) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Advanced Guidance and Control : Operational and Safety Benefits
This provides access to a Federal Aviation Administration(FAA) report DOT/FAA/AR-08/27 written by Mohamed Eladi ...[et al] and dated June 2008. This project originally titled "Assessment of Operational and Safety Benefits of Functionally Integrated Flight Guidance and Control" was retitled "Advanced Guidance and Controlâ€”Operational and Safety Benefits" with the funding participants in mind (FAA, Honeywell, Gulfstream, and Smiths Aerospace) and with the goal of emphasizing the benefits that would accrue to these participants (government and industry). The project launched with multiple objectives, one of which included evaluating the suitability and effectiveness of this technology compared to a more traditional control scheme. Of particular interest was the ease of reuse and the associated performance achievable with the generic design when applied to an actual production program. The generic Total Energy Control System (TECS) outer loop design was evaluated for reuse and robustness without customizing the TECS outer loop design to achieve optimum performance. Instead, a test of the TECS was chosen in which the outer loop design of a traditional autoflight system was replaced with the TECS outer loop design. Very few adjustments were made to the Federal Aviation Administration-provided generic TECS outer loop design. No modifications were made for compatibility of the inner loop and outer loop designs for the hybrid system. The only modifications involved aligning the operational philosophies of the two control approaches so that a tangible performance comparison could be performed. A series of flight scenarios were run to compare the performance of the hybrid TECS/traditional design with the customized traditional design. Of particular interest was the relative performance of the two systems. Since the traditional system was tuned to yield a desired performance, a good response match of the TECS hybrid system would indicate good viability for reuse. The absolute performance of the systems was deemed less meaningful because many other factors independent of the control approach, such as simulation model fidelity, adversely influenced the absolute performance. Significantly improved TECS performance, over and above what is presented in this report, would likely be achieved by tuning the TECS. [Taken from abstract]. The full text is available in PDf format so Adobe Acrobat is required in order to read it.
Advances in Flight Testing
This is Research and Technology Organization(RTO) AGARD Conference Proceedings, AGARD-CP-593, dated December 1997. This proceedings was sponsored by the Flight Vehicle Integration Panel Symposium, held in Lisbon, Portugal, 23-26 September 1996. The Symposium comprised six sessions, each being devoted to a particular field, with one session on Systems Evaluation, including avionics, navigation, propulsion and weapons aspects, two sessions on Technological Advances covering all technical fields such as avionics software, simulation, instrumentation, aerodynamics, test methods etc., one session devoted to an Overview of Current Programmes, one session on Flight Dynamics, incorporating handling qualities, performance and flight controls, and one session addressing Management Problems in Testing. The symposium closed with a discussion between government representatives and manufacturers on "The role of governments in development testing in the 21st century". Bibliographic and abstract details are available in HTML format. A table of contents, and the full text of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
AEgis Simulation Inc. - ACSL (Advanced Continuous Simulation Language) Software
ACSL (Advanced Continuous Simulation Language) products are owned by AEgis Software. Aerospace and defence applications of ACSL software products include: simulation of fixed and rotary wing flight dynamics; missile simulation, marine propulsion system simulation; and simulation of spacecraft dynamics. The site provides access to a range of information resources including: a product overview, a description of industry applications, and details of ACSL training programmes. The publications section provides access to a collection of papers in the ACSL electronic library. These cover many topic areas such as: aeronautics, aircraft design, aerodynamics, unmanned aircraft, engines, flight simulations, and vehicle dynamics. The full-text papers seem to be available in a variety of formats including HTML and PDF.
AEgis Technologies Group
AEgis is involved in the development and design of products to be used in High Level Architecture (HLA) solutions. The interests of the company include simulation support, simulation-based systems analysis, systems engineering, optical systems design and fabrication. The site includes a corporate overview, and descriptions of AEgis products and services. There is a collection of online papers produced by the company, details of current projects being undertaken, and a page devoted to Advanced Continuous Simulation Language (ACSL) software products.
Aeroelastic Analysis of a Joined-Wing Sensorcraft
This is a full text thesis by Jennifer J. Sitz which was presented to the Air Force Institute of Technology (AFIT) in 2004. This study performed an aeroelastic analysis of a joined-wing SensorCraft. The analysis was completed using an aluminum structural model that was splined to an aerodynamic panel model. The force and pressure distributions were examined for the four aerodynamic panels: aft wing, fore wing, joint, and outboard tip. Both distributions provide the expected results (elliptical distribution), with the exception of the fore wing. The fore wing appears to be affected by interference with the joint. The use of control surfaces for lift and roll was analyzed. Control surfaces were effective throughout most of the flight profile, but may not be usable due to radar requirements. The aft wing was examined for use in trimming the vehicle. Also, two gust conditions were examined. In one model, the wing twist was simulated using a series of scheduled control surfaces. Trim results (angle of attack and twist angle) were compared to those of previous studies, including gust conditions. The results are relatively consistent with those calculated in previous studies, with variations due to differences in the aerodynamic modeling. To examine a more physically accurate representation of aft wing twist, it was also modeled by twisting the wing at the root. The twist was then carried through the aft wing by the structure. Trim results were again compared to previous studies. While consistent for angle of attack results, the aft wing twist deflection remained relatively constant throughout the flight profile and requires further study. [Taken from abstract]. The full text of the thesis is available in PDF format and is provided by the Air University ResearchWeb site.
Aeronautics Learning Laboratory for Science Technology and Research
This educational website includes material on the history of aeronautics, principles of aeronautics and aerospace education and careers at three different levels: Level 1 - for middle/junior high school students; Level 2 - for junior high/high school students and Level 3 - for high school/lower division college students. A teachers guide is available along with information on research projects, relevant links and a photo gallery. There is also information on how to obtain the teaching material on a CD-ROM.
Aerospace Testing Expo 2005
This site offers access to the PowerPoint presentations of many of the papers presented at this conference. Papers are provided on a range of testing disciplines with specialist papers also on wind tunnel testing, non-destructive testing (NDT) and flight testing. The conference was held in Hamburg, Germany from 4-6 April 2005.
Aircraft Research Association Ltd
This is an indepedent not-for-profit research and development organisation which is concerned with aerodynamic design, particularly wind tunnel testing. The site provides an overview of the activities of ARA (Aircraft Research Association) including news and vacancies and descriptions of the facilities (primarily wind tunnels) available. The site gives brief details about its interests in computational fluid dynamics (CFD) including grid generation, turbulence modelling and drag prediction.
Aircraft Weapon System Compatibility and Integration
This web site provides access to a Research and Technology Organization Meeting Proceedings, RTO-MP-016, Paris, April 1999. The documents contains papers presented at the RTO Systems Concepts and Integration Panel (SCI) Symposium held in Chester, United Kingdom, 28-30 September 1998. The objectives of the symposium were to review the overall state-of-the-art in aircraft weapon system compatibility and integration and to inform possible paths for future development. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (29 Mbytes) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library
Alleviation of Buffet-Induced Vibration Using Piezoelectric Actuators
This is the full text of a Master's thesis by Captain Shawn D. Morgenstern, USAF, AFIT/GAE/ENY/06-M25, which was presented to the Faculty Graduate School of Engineering and Management of Air University's Air Force Institute of Technology (AFIT), in February 2006. Buffet-induced vibration has been problematic for aircraft structures for many years. The F-16 ventral fin, while prone to these effects, lends itself well to the evaluation of modern active structural and flow control technologies. The objective of this research was to determine the most critical natural modes of vibration for the F-16 ventral fin and design piezoelectric actuators capable of reducing buffet-induced ventral fin vibration. A finite element model (FEM) for the fin was developed, tuned and optimized to closely match published modal frequencies. Piezoelectric actuator patches were designed using the strain characteristics of the FEM and integrated into the model using a thermal analogy which allowed voltage application and the resulting strain to be simulated by a change in temperature. Two phases of critical mode selection were completed and included reviews of existing flight test data, historical ventral fin failure characteristics, and the results of aeroelastic and closed-loop aeroservoelastic analyses conducted on the FEM. Results showed the FEM tuning and optimization procedures, as well as the design and implementation process for the piezoelectric actuators to be very effective. Modes 1, 2 and 4 were determined to be the most suitable for future application of the technology. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Alternative Control Technologies : Human Factors Issues
This web site provides access to an Educational Note produced by the Research and Technology Organization (RTO), RTO-EN-003, dated October 1998. The material was assembled to support a Lecture Series (Lecturer Series 215) under the sponsorship of the Human Factors and Medicine Panel and the Consultant and Exchange Programme of RTO presented on 7-8 October 1998 in Brétigny, France, and on 14-15 October 1998 at Wright-Patterson Air Force Base, Ohio, USA. The main aim of the lecture Series was to review alternative control technologies such as voice, and head and eye movement commands, and to provide for discussion on their main characteristics, benefits, and limitations. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text of the document (17.5 Mbytes) can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
An Analytical Study of T-38 Drag Reduction in Tight Formation Flight
This is the full text of a thesis by Eugene H. Wagner which was presented to the Air Force Institute of Technology (AFIT) in 2002. This thesis explores the benefits of flying in a tight formation, mimicking the natural behavior of migratory birds such as geese. The first phase of the research was to determine an optimal position for the wingman of a tight formation flight of T-38 Talon aircraft using the HASC95 vortex lattice code. A second wingman was then added to determine the benefit derived by increasing formation size. The second wingman was predicted to derive an even greater induced drag benefit than the first wingman for T-38s operating at Mach 0.54 at a 10,000-foot altitude. The predicted values were 17.5% savings for the second wingman versus 15% for the first wingman. The flight test phase flew two and three-ship formations to validate the computational work. The results of the two-ship flight tests showed with 80% confidence that the wingman saved fuel in the predicted optimal position (86% wingspan lateral spacing). This position yielded actual fuel savings of 8.8% ± 5.0% versus the predicted 15%. The other lateral positions did not show a statistically significant fuel savings. The flight test team felt that the three-ship formation data was inconclusive due to the difficulty of trying to fly a stable position as the third aircraft in the formation without station-keeping ability. [Taken from abstract]. The full text of the thesis is available in PDF format and is porvided by the Air University ResearchWeb site.
An Evaluation of Methods to Separate Maneuver and Gust Load Factors From Measured Acceleration Time Histories : Final Report
This provides access to a Federal Aviation Administration (FAA) report, DOT/FAA/AR-99/14, by John W. Rustenburg, Donald Skinn, and Daniel O. Tipps, dated April 1999. This report presents the results of a study to evaluate the validity and operational processing efficiency of three different methods for the separation of maneuvers and gusts from measured acceleration data obtained from Optical Quick Access Recorder (OQAR) equipped commercial aircraft. The full text of the report is available in PDF format from the online catalogue of the FAA William J. Hughes Technical Center Library.
An Investigation Relating Longitudinal Pilot-Induced Oscillation Tendancy Rating to Describing Function Predictions for Rate-Limited Actuators
This is the full text thesis by Joel B. Witte which was presented to the Air Force Institute of Technology (AFIT) in 2004. The purpose of this study was to investigate pilot-induced oscillations (PIO) and determine a method by which a PIO tendency rating could be predicted. In particular, longitudinal PIO in the presence of rate-limited actuators were singled out for examination. Sinusoidal input/triangular output describing function techniques using Nichols charts were used. A new criterion dubbed Gap Criterion was calculated for PIO sensitivity. This criterion consists of the product of additional pilot gain and the normalized maximum amplitude of the commanded actuator necessary to cause PIO. These results were paired with simulator and flight test PIO tendency rating data. The PIO rating scale used was the PIO tendency classification of MIL-HDBK-1797. This concept was applied to two historical test databases, HAVE PREVENT and HAVE OLOP. Additional PIO data was gathered in the Large Amplitude Multimode Aerospace Simulator (LAMARS) at the Air Force Research Laboratory (AFRL), Wright-Patterson AFB, Ohio and the USAF NF-16D Variable In-flight Stability Test Aircraft (VISTA) at Edwards AFB, California. Correlation between PIO tendency rating and Gap Criterion was determined for each dataset. Most datasets exceeded a confidence level of 95% that a correlation existed. Follow-on analysis for better curve fitting was accomplished; a logarithmic fit was judged best. Datasets were combined with success to demonstrate the universality of the Gap Criterion for correlating PIO tendency ratings for longitudinal PIO involving rate-limited actuators. [Taken from abstract]. The full text of the thesis is available in PDF format and is provided by the Air University ResearchWeb site.
ANSYS FLUENT software contains the broad physical modelling capabilities needed to model flow, turbulence, heat transfer, and reactions for industrial applications ranging from air flow over an aircraft wing to combustion in a furnace, from bubble columns to oil platforms, from blood flow to semiconductor manufacturing, and from clean room design to wastewater treatment plants. Special models that give the software the ability to model in-cylinder combustion, aero-acoustics, turbo-machinery, and multiphase systems have served to broaden its reach.
Application of Damage Tolerance Principles for Improved Airworthiness of Rotorcraft
This web site provides access to a NATO Research and Technology Organization (RTO) report titled: Application of Damage Tolerance Principles for Improved Airworthiness of Rotorcraft, RTO-Mp-024, February 2000. The report contains papers presented at the Applied Vehicle Technology Panel (AVT) Specialists Meeting, held in Corfu, Greece, 21-22 April 1999. The metting addressed issues associated with aging systems, and in particular with the application of damage tolerance principles for improved airworthiness of rotorcraft. The papers were grouped into three sessions covering the following: materials data and crack growth models for damage tolerance approaches to helicopter structures; design application of DT principles; and operator experience and certification issues. The citation and abstract information is in HTML format, and the full text is available online in PDF format (23 Mbytes).
Automatic Control of an Aircraft Employing Outboard Horizontal Stabilizers
This is a University of Calgary, Department of Mechanical and Manufacturing Engineering PhD thesis, by Jason Mukherjee, dated March 2000. It examines the radio-operated control of an aircraft using fixed gain and adaptive controllers. A real-time feedback control system is developed to enhance the flying qualities of an experimental model aircraft. The Outboard Horizontal Stabilizer (OHS) concept is a nonconventional aircraft, designed to take advantage of the normally wasted energy developed by the wing tip vortices. The research is based on a remotely-controlled OHS aircraft fitted with various sensors and telemetry as part of a real time feedback control system. Bibliographic and abstract details are available in HTML format. The full text of the thesis accessible online in PDF format. This title is part of Library and Archives (LAC) Canada's theses collection. Access is provided via the Theses Canada Portal
Aviation Safety and Pilot Control: Understanding and Preventing Unfavorable Pilot-Vehicle Interaction
Aviation Safety and Pilot Control: Understanding and Preventing Unfavorable Pilot-Vehicle Interactions, report prepared by the Committee on the Effects of Aircraft-Pilot Coupling on Flight Safety, National Research Council, 1997. 220 pages. The report evaluates the current state of knowledge about adverse APC and processes that may be used to eliminate it from military and commercial aircraft. The web site provides access to the full text of the report. It is available online in two formats: Open Book and HTML.
Basic Principles of Flight Test Instrumentation Engineering
This is Research and Technology Organization (RTO) AGARD-AG-160 Vol.1, dated April 1974. This report describes the a careful consideration that was taken into account for the design of flight test instrumentation system in aircrafts. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (181KB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Central Aerohydrodynamic Institute (TsAGI)
The site provides information about one of the key Russian state aerospace research centers. Information on the site is arranged under a number of activity areas including; aerodynamics, flight dynamics, strength, hydrodynamics, measuements, and non-aerospace activities. The site provides general information about the Institute including a brief history and image gallery. The Institute's test facilities are described, a list of staff publications and news and contacts sections.
Chris Heintz Design College
This web site brings together a number of full text articles that deal with various aspects of light aircraft design. Fourteen of the articles were published in the Experimental Aircraft Association's (EAA) Light Plane World or Experimenter publications. The topics covered include: light aircraft materials and their properties; flight and performance testing; riveted joints; airfoils; pitch, stability and control; control surfaces; determining weight and balance; and STOL aircraft design. The author, Chris Heintz, is resonsible for the design of a range of kit aircraft for the Zenith Aircraft Company.
Collaboration for Land, Air, Sea, and Space Vehicles : Developing the Common Ground in Vehicle Dynamics, System Identification, Control, and Handling Qualities
This site provides access to a Research and Technology Organisation (NATO) Technical Report, RTO-TR-061, Paris, November 2002. This report presents the results of a study conducted by the RTO Systems Concepts and Integration Panel (SCI) Task Group SCI-53, Vehicle Dynamics, System Identification, Control and Handling Qualities. This report addresses the second goal of the SCI-53 technical team, namely to build mechanisms to assist the co-ordination and integration of experts working in the different operational environments. It provides a preliminary review of the issues involved in vehicle dynamics, modeling and system identification, control, and handling qualities as these topics apply to modern military vehicles in all four environments. By focusing on the commonalties and differences between the four environments, this report will also serve to highlight areas of potential collaboration between experts from the various technical communities. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text of the document (9.06 Mbytes) can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Commercial Supersonic Technology : The Way Ahead
This provides access to a report prepared by the National Research Council, Aeronautics and Space Engineering Board's Committee on Breakthrough Technology for Commercial Supersonic Aircraft, National Academy Press, 2002. The report documents the results of a study requested by NASA which aims to identify approaches for achieving breakthroughs in supersonic research and technology. It identifies five areas for new focused research to enable industry production by the year 2025 of an environmentally acceptable, economically viable commercial aircraft capable of sustained supersonic flight, including flight over land, at speeds less than approximately Mach 2. The text is available in Open Book and HTML formats.
Computational Aeroelastic Analysis of Aircraft Wings Including Geometry Nonlinearity
This is a University of Cincinnati, Department of Aerospace and Engineering Mechanics PhD thesis, by Binyu Tian, 2003. The objective of the study is to show the ability of solving fluid structural interaction problems more realistically by including the geometric nonlinearity of the structure so that the aeroelastic analysis can be extended into the onset of flutter, or in the post flutter regime. A nonlinear Finite Element Analysis software is developed based on second Piola-Kirchhoff stress and Green-Lagrange strain. The nonlinear Finite Element Analysis software developed in this study is verified with ANSYS, NASTRAN, ABAQUS, and IDEAS for the linear static, nonlinear static, linear dynamic and nonlinear dynamic structural solutions. To solve the flow problems by Euler/Navier equations, the current nonlinear structural software is then embedded into ENSAERO, which is an aeroelastic analysis software package developed at NASA Ames Research Center. The aeroelastic analysis results have been obtained for fight wing in the transonic regime for various cases. The influence dynamic pressure on flutter has been checked for a range of Mach numbers. Bibliographic and abstract details are available in HTML and the full text of the document is accessible online in PDF format (27.62 Mb). This title is part of the OhioLINK Electronic Theses and Dissertations (ETD) Service
Computers Take Flight
This web site provides access to a NASA Dryden Flight Research Center history series publication, NASA SP-4303, by James E. Tomayko. This describes the history of the F-8 Digital Fly-By-Wire Project. This produced the first digital fly-by-wire aircraft to operate without a mechanical backup system. The full text of the publication is available online in HTML format.
Control Engineering Virtual Library
This document is provided by the Cambridge University Engineering Department Control Group. It provides links to a wide ranging collection of links to web resources on control engineering arranged under the following headings: what's new?, control conferences, control groups around the world, E-letter (the archive of the E-letter on systems, Ccntrol, and signal processing), professional societies, journals, control information services and commercial organisations. Issues of the E-letter are accessible in full text as HTML documents back to Issue 40, 1991.
Convex Modeling Techniques for Aircraft Control
This web site provides access to a Virginia Polytechnic Institute and State University Department of Aerospace and Ocean Engineering MSc thesis, by Abhishek Kumar, dated 7 June 2000. Bibliographic and abstract details are available in HTML format. The full text of the document is accessible online in PDF format [1.14 Mb]. This title is part of Virginia Techï¿½s Electronic Thesis and Dissertation Collection (VT ETD).
Cooperative Programme on Dynamic Wind Tunnel Experiments for Manoeuvring Aircraft
This is Research and Technology Organization (RTO) AGARD Advisory Report, AGARD-AR-305, dated October 1996. This report describes a multinational cooperative program set up by the AGARD Fluid Dynamics Panel in response to the continuing interest among the NATO countries in dynamic wind tunnel testing. Such testing is essential for obtaining the aerodynamic information required to predict the behavior of an aircraft performing angular motions. At low angles of attack this occurs primarily when the aircraft performs a small-amplitude oscillatory motion resulting from a disturbance or a control deflection. The dynamic stability can then be predicted by solving linear equations of motion in which the aerodynamic reactions are represented by the so called stability derivatives, obtainable from oscillatory experiments. At high angles of attack this occurs when the aircraft is involved in a spin, in which case rotary-balance data are required, or performs a rapid maneuver, in which case both rotary-balance and large amplitude oscillatory data are needed. Such data are often non-linear and time dependent, compounding the complexity of the prediction and analysis. Bibliographic details and an abstract are available in HTML format and the full text is available in PDF format(35 Mb)from the RTO's web site.
Cranfield University Aerospace
Cranfield has been at the forefront of the development of aerospace technology for 60 years and is one of the largest academic centres in western Europe for strategic applied research, development and design. Cranfield University Aerospace brings together the Universityâ€™s aerospace capabilities from all its five Schools into areas of strategic importance for its clients, within the aerospace and aviation markets. It consists of the following technology areas: flow control and prediction, computer integrated design, air transport management, human factors, avionics and simulation, structures and materials, air vehicle technology, flight test and dynamics and astronautics and space engineering. The site details Cranfield University Aerospace's capabilities, courses and current projects.
This is the web site of the Faculty of Aerospace Engineering, Delft University. It describes the various educational programmes on offer along with supporting course information. There is also information on the various research groups, facilities, support services, student organisations as well as the Delft Aerospace Alumni Society. Other sections of the site include news and events, and a database of staff contact information.
Delphion Patent Search Form
This site allows you to search for United States patents, European patents and patent applications, Patent Cooperation Treaty (PCT) application data from the World Intellectual Property Office, the Patent Abstracts of Japan and INPADOC data. The service can be searched in several different ways, including patent number, US classification and Boolean keyword search. It is possible to view to the bibliographic information of granted US patents free of charge, all other services are payable. You will need to register to use this service, which is free of charge.
Department of Aeronautics and Astronautics at the University of Southampton
The Department of Aeronautics and Astronautics at the University of Southampton is a member of the School of Engineering Sciences. The department name reflects the international reputation of Southampton in both Aeronautics & Astronautics and encompasses a broad range of disciplines within the field of aerospace engineering with applications to the specification, design and construction of airframes, engines, satellites and other spacecraft. These disciplines include aerodynamics, flight mechanics, materials, propulsion, structures, as well as aircraft and spacecraft systems. Cutting-edge research into all these disciplines is carried out within the School of Engineering Sciences by recognised experts in their specific fields. The web site gives information about the department, staff, research interests, the undergraduate and postgraduate courses available, facilities, including a wind tunnel complex which ranges from low speed to hypersonic, as well as the Department's links with industry and government research laboratories.
Department of Aeronautics at the Imperial College of Science, Technology and Medicine
The Web Site provides information on all major activities which are carried out by the Department, including teaching programmes, research and Departmental facilities, as well as the Departmental Staff. It contains information about the eight research groups - the Biomedical Flows Group, the Bluff Bodies and Vortex Flow Group, the Hypersonics Research Group, the Turbulence Mixing and Flow Control Group, the Spectral/hp Element Methods Group, the Geophysical Fluid Dynamics Group, the Turbulent Flow Modelling Group and the Flow Control Group. There are also links through to information about the Centre for Composite Materials within the department and the Honda Wind Tunnel. Details of undergraduate and postgraduate courses, short courses and research seminars are also provided.
Dryden Technical Reports Server (DTRS)
This service is available to search as part of the NASA Technical Reports Server, or on its own from this site. It is possible to search for and view details of reports, and view the full text of reports in PDF format from this service. Reports are available back to 1947 and up to the present day.
Dynamic Aeroelastic Analysis of Wing/Store Configurations
This is the full text of a Doctoral thesis by Major Gregory H. Parker, USAF, AFIT/DS/ENY/06-06, which was presented to the Faculty Graduate School of Engineering and Management of Air University's Air Force Institute of Technology (AFIT), in December 2005. Limit-cycle oscillation, or LCO, is an aeroelastic phenomenon characterized by limited amplitude, self-sustaining oscillations produced by fluid-structure interactions. In order to study this phenomenon, code was developed to interface a modal structural model with a commercial computational fluid dynamics program. LCO was simulated for a rectangular wing, referred to as the Goland+ wing. It was determined that the aerodynamic nonlinearity responsible for LCO in the Goland+ wing was the combination of strong trailing-edge and lambda shocks which periodically appear and disappear. This mechanism limited the flow of energy into the structure which quenched the growth of the flutter, resulting in a steady LCO. Under-wing and tip stores were added to the Goland+ wing to determine how stores affected limit-cycle oscillation. It was found that aerodynamic store shapes affect LCO in two off-setting ways: under-wing stores interfere with the airflow on the lower surface of the wing which decreases LCO amplitudes, whereas, aerodynamic forces on both under-wing and tip stores directly increase LCO amplitudes. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Effects of Large-Droplet Ice Accretion on Airfoil and Wing Aerodynamics and Control : Final Report
This provides access to a Federal Aviation Administration (FAA) report, DOT/FAA/AR-00/14, by Michael B. Bragg and Eric Loth, dated March 2000. The report describes an experimental and computational investigation to determine the effect of simulated ridge ice shapes on airfoil aerodynamics. The full text of the report is available in PDF format from the online catalogue of the FAA William J. Hughes Technical Library.
ESDU create and maintain over 22 series of validated engineering design data covering structural, mechanical, aeronautical and chemical process engineering. They are produced by committees of independent experts who ensure that each Data Item is a sound technical document which presents a clear explanation of the recommended approach. The bulletins that each committee produce are available for viewing using Adobe Acrobat. Subscribers to the service can access the full text of all data items. Non subscribers may view abstracts of each Data Item. An FAQ, glossary and technical notes are also available.
Estimation of Landing Stopping Distances from Flight Data
This provides access to a Federal Aviation Administration (FAA)technical report DOT/FAA/AR-09/46 written by Gerard W.H. van Es, Peter J. van der Geest, Andrew Cheng and Larry Hackler dated February 2010. The need for improved capacity at airports to accommodate the rapid growth of air traffic has led to the investigation of operational landing performance as a safe and feasible means to increase the traffic flow. While the capacity issue becomes important, it is imperative that the increase in capacity does not let safety decline. A key task is to investigate the airplane landing performance to provide operations safety guidelines for reducing the risks of incidents and accidents associated with new technologies and procedures. For this, a clear knowledge of the day-to-day landing operations is required. The objective of the present study was to derive and analyze methods for calculating the full-stop landing distance from flight operational data. In total, eight methods have been defined to calculate the ground distance from actual landing data. All these variants have been implemented in the processing software. After reprocessing all available cases, the statistical properties and possible correlations of each variant were investigated and presented. Based on these results, it was concluded that ground stopping distances obtained with the maximum instantaneous deceleration approach may be considered as the most useful or realistic candidate to serve as an indicator for the actual airplane landing performance. [Taken from abstract]. The full text is available in PDF format from the online catalogue of the William J. Hughes Technical Center Library.
European Aeronautics Science Network (EASN)
This is a three year funded project which aims to bring the European universities with aeronautics activities into an integrated network, operating in parallel with industry and the national research establishments. EASN has a Steering Committee representing partners to oversee the activities of the network, as well as a number of Interest Groups (IGs) addressing various thematic issues. There are 10 interest areas covering Flight Physics, Aerostructures, Propulsion, Aircraft Avionics Systems and Equipment, Flight Mechanics, Integrated Design and Validation, Air Traffic Management, Airports, Human Factors, and Innovative Concepts and Scenarios. Within these areas several Interest Groups have been established for Advanced Combustion Chambers, Ageing Aircraft, Crashworthiness and Structural Impact, Emission Minimizing Flight Operations, Fault Tolerant Systems, Increased Exploitation of Composites, Manufacturing Processes and Technologies of Aero-Engines, Risk Analysis Based LCE in Aeronautics, Surface Engineering Treatments, Vortical Structures and IG Innovative Contacts and Scenarios. The central element is an open, Internet based network that will enable communication between groups and will provide access to a database. The Network Database contains Information on the university institutes with their aerospace competence profiles, companies and organisations in the aerospace supply chain, research establishments and information on national aeronautics research programmes. The web site describes the network members and provides details of each of the regional contact points. It identifies R&T areas and Interest Groups and the Universities who are engaged in research activities in these areas. The site also provides news and a list of related links.
Experimental Investigation Into the Aerodynamic Ground Effect of a Tailless Chevron-Shaped UCAV
This is the full text of a Master's thesis by Ensign Brett L. Jones, USNR, AFIT/GAE/ENY/05-J04, which was presented to the Faculty Department of Aeronautics and Astronautics of Air University's Air Force Institute of Technology (AFIT), in June 2005. This experimental study adequately identified the ground effect region of an unmanned combat air vehicle (UCAV). The AFIT 3' x 3' low-speed wind tunnel and a ground plane were used to simulate the forces and moments on a UCAV model in ground effect. The chevron planform used in this study was originally tested for stability and control and the following extends the already existing database to incude ground effects. The ground plane was a flat plate mounted with cylindrindrical legs. To expand the capabilities of the AFIT 3' x 3' low-speed wind tunnel, hot-wire measurements and flow visualization revealed an adequate testing environment for the use of the ground plane. Examination of the flow through the test section indicated a significant difference in test section transducer velocity and the hot-wire measured velocity. This disparity along with the velocity difference due to the ground plane were accounted for as wind tunnel blockage. In addition, the flow visualization revealed the horseshoe vortices that built up on the front two mounted legs of the ground plane. The ground effect region for the chevron UCAV was characterized by an increase in lift, drag, and a decrease in lift-to-drag ratio. These trends were also noted in previous studies of similar aspect ratio and wing sweep. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Flight Control Design : Best Practices
This web site provides access to a Research and Technology Organization (RTO) Technical Report, RTO-TR-029, dated December 2000. The report was sponsored by the former Flight Vehicle Integration Panel of AGARD, and the Systems, Concepts and Integration (SCI) Panel of RTO. It presents a review of some examples of flight control problems, the positive lessons learnt, as well as some recommended design best practices. The report looks at the theory of Pilot Induced Oscillations (PIOs) and handling qualities. It concludes with suggestions for required future research. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text of the document (4.66 Mbytes) can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Flight Control Failure Detection and Control Redistribution Using Multiple Model Adaptive Estimation with Filter Spawning
This is the full text of a thesis by Michael L. Torres which was presented to the Air Force Institute of Technology (AFIT) in 2002. Failure detection for aircraft sensor and actuator/actuating-surface systems and flight control redistribution in response to failed actuators/surfaces is an important research area. With the advent of faster flight control computers with greater memory available, parallel adaptive estimators can now be used to determine sensor and flight control actuator/surface failures. Since most of the sensors are somewhat functionally redundant, when a sensor is lost, the information it would have provided could be estimated from other operational sensors using a Kalman Filter. If a flight control actuator or surface fails, then a system having access to all the other flight control actuators/surfaces can properly adjust the remaining control actuators/surfaces (i.e., employ control redistribution) in order to achieve the commanded maneuver. Research has been accomplished in this area using Multiple Model Adaptive Estimation (MMAE) to detect failures. Flight Control Redistribution (CR) is then used to compensate automatically for a failed flight control actuator/surface assuming that there is enough control authority in the aircraft. The MMAE is used to detect and identify flight control failures and also to provide estimated sensor outputs in the event of a failed sensor. Further research has been accomplished looking at single and multiple failures and MMAE with Filter Spawning (FS) to detect complete and partial failures. Flight control redistribution has also been researched. In the current research, the MMAE with Filter Spawning and Control Redistribution (MMAE/FS/CR) are used together to identify failures and apply appropriate corrections. This research effort explores the performance of the MMAE/FS/CR in different regions of the flight envelope using model and gain scheduling. [Taken from abstract]. The full text of the thesis is available in PDF format and is provided by the Air University ResearchWeb Site.
Flight Dynamics and Control Toolbox
This freely downloadable software provides flexible models and tools for flight simulation, flight dynamics analysis and flight control system design. The open source software is available for both Matlab and Simulink and has been created by and is maintained by a member of staff from KLM. A user manual containing detailed theoretical background information is also available.
Flight Test Measurement Techniques for Laminar Flow
This is Research and Technology Organization (RTO) AGARDograph, RTO-AG-300-V23, edited by D. Fisher, K.H. Horstmann and H. Riedel; sponsored by the Flight Test Technology Team (FT3) of the Systems Concepts and Integration Panel (SCI) of RTO, dated October 2003. This AGARDograph provides information on flight test techniques, instrumentation, environmental effects, and flight procedures that have been used successfully in laminar flow research. Many techniques are described for measuring the location of boundary layer transition in-flight, from the very simple to the more complex. References to previous works are included for readers to explore. Specific instrumentation for flight is described and the unique environmental effects of flight noted. Procedures for flight test maneuvers are also included. Techniques discussed cover both local and global measurements. Some of the local flow techniques include surface temperatures, hot-film and hot-wire anemometry, raised-pitot, and traversing surface pitot. Global flow techniques include the infrared imaging, oil flow, liquid crystal, sublimating chemicals, and emitted fluid techniques. Some of the environmental concerns discussed include atmospheric particulate (ice crystals) and turbulence. Flight test procedures for infrared imaging and for insect contamination avoidance are described. Bibliographic details and an abstract are available in HTML format. The full text can be accessed online in PDF format (103 Mb) from the RTO's web site.
Flight Test â€“ Sharing Knowledge and Experience
This site provides access to the Research and Technology Organisation (RTO) Meeting Proceedings, RTO-MP-SCI-162. The papers are from the RTO Systems Concepts and Integration (SCI) Symposium, held in Warsaw, Poland, 9-11 May 2005. Topics covered by the papers include: Programme Operations; Test Methods; Programmes Overview; Facilities and Flight Test Instrumentation; Programmes â€“ Operations. The document is contained in the RTO's Publication Library.
This is Research and Technology Organization (RTO) AGARD-CP-519, dated October 1992. It is considered by the Flight Mechanics Panel of AGARD as vitally important that the NATO flight test community meet regularly so that new techniques for flight test, instrumentation and data analysis and lessons learned from past and on-going programs be disseminated to ensure that safe efficient cost-effective and timely testing is accomplished. There are many new systems being tested or planned for testing in the near future. These include programmable signal processor radars, integrated flight, fire and propulsion control systems, thrust vectoring, low observable technologies, multifunction pilot displays and multisensor integration. Acquisition and processing of large quantities of avionics multiplex data are challenges that must be met. There is a need for greater use of simulators and other hardware-in-the-loop ground test facilities. For individual titles, see N93-19902 through N93-19930. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (115.11MB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Fluid Dynamics Problems of Vehicles Operating Near or in the Air-Sea Interface
This site provides access to a Research and Technology Organization Meeting Proceedings, RTO-MP-015, Paris, February 1999. The document contains papers presented at the RTO Applied Vehicle Technology Panel (AVT) Symposium (organised by the former AGARD Fluid Dynamics Panel), held in Amsterdam, The Netherlands, 5-8 October 1998. Topics covered at the symposium included aerodynamics and flight dynamics around ships, stabilization and control techniques for ships, and non-classical aircraft flying near the air-sea interface. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (46.2 Mbytes) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library
Flying Qualities Flight Testing of Digital Flight Control Systems
This web page provides access to a Research and Technology Organization (RTO) AGARDograph, RTO-AG-300-V21, prepared by F. Webster and T.D. Smith in December 2001. It was sponsored by the SCI-055 Task Group, the Flight Test Technology Team of the Systems Concepts and Integration Panel (SCI) of RTO. The report highlights the basics of flying qualities flight testing for digital flight control systems (DFCS). Special emphasis is placed on test preparation and data analysis. It presents a compilation of best practice developed over the years by the test community. Bibliographic details and an abstract are available in HTML format and the full text is available in PDF format (1 Mb).
Foresight â€“ Department for Business Innovation and skills
Our aim is help the UK government think systematically about the future. The Programme helps to improve how we use science and technology within government and society. Our work achieves this by drawing on well tested scientifically valid techniques to inform those responsible for developing policy and strategy in government.
Head Tracking for 3D Audio Using a GPS-Aided MEMS IMU
This is the full text of a Master's thesis by Captain Jacque M. Joffrion, USAF, AFIT/GE/ENG/05-09, which was presented to the Faculty of the Department of Electrical and Computer Engineering of Air University's Air Force Institute of Technology (AFIT), in March 2005. Audio systems have been developed which use stereo headphones to project sound in three dimensions. When using these 3D audio systems, audio cues sound like they are originating from a particular direction. There is a desire to apply 3D audio to general aviation applications, such as projecting control tower transmissions in the direction of the tower or providing an audio orientation cue for VFR pilots who find themselves in emergency zero-visibility conditions. 3D audio systems, however, require real-time knowledge of the pilot's head orientation in order to be effective. This research describes the development and testing of a low-cost head tracking system for 3D audio rendering applied in general aviation. The system uses a low-cost MEMS IMU combined with a low-cost, single frequency GPS receiver. Real-time data from both of these systems was sent to a laptop computer where a real-time Kalman filter was implemented in MATLAB to solve for position velocity, and attitude. The attitude information was then sent to a 3D audio system for sound direction rendering. The system was flight tested on board a Raytheon C-12C aircraft. The accuracy of the system was measured by comparing its output to truth data from a high-accuracy post-processed navigation-grade INS/DGPS solution. Results showed that roll and pitch error were accurate to within 1-2 degrees, but that heading error was dependent upon the flight trajectory. During straight-and-level flight, the heading error would drift up to 10-15 degrees because of heading unobservability. However, even with heading error, the ability of a pilot to determine the correct direction of a 3D audio cue was significantly improved when using the developed head tracking system over using the navigation-grade INS/GPS system fixed to the aircraft. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Inertia Measurement and Dynamic Stability Analysis of a Radio-Controlled Joined-Wing Aircraft
This is the full text of a Master's thesis by Captain William A. McClelland, USAF, AFIT/GA/ENY/06-M07, which was presented to the Faculty Department of Aeronautical Engineering of Air University's Air Force Institute of Technology (AFIT), in March 2006. Dynamic stability and stall during steady level turns were examined for VA-1, a joined-wing flight demonstrator aircraft. Configurations with a lower vertical tail and fairings over the main landing gear were compared with a recommendation on the combination had the best drag and dynamic stability characteristics. The dynamic stability analysis was broken into four key parts: a twist test experimentally measured mass moments of inertia, a panel method was used to find non-dimensional stability derivatives, lateral and longitudinal state space models estimated dynamic stability characteristics and handling quality levels were evaluated using a Cooper-Harper based rating system. VA-1 was found to have good longitudinal and lateral flight qualities for cruise flight. The lower vertical tail could be removed to reduce weight and drag without degrading dynamic stability. Spanwise lift coefficients for different wing sections in trimmed steady state turns at 50 and 55 degrees of bank were estimated to see which sections of the wing stalled first. The analysis revealed VA-1 can turn using bank angles less than 50 degrees without stall and that stall first occurred at the aileron, immediately outboard of the wing joint. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Institute for Aerospace Research
The Institute for Aerospace Research (IAR) is Canada's national aerospace laboratory. This site provides a range of introductory information which includes online access to the current strategic plan. The core content of the site is devoted to the four constituent IAR laboratories: Aerodynamics; Flight Research; Structures, Materials and Propulsion and Aerospace Manufacturing Technology. Each of these sections contain largely descriptive information on specific areas of research interest and expertise. The full-text of IAR Flyer, a newsletter, is also available online.
Introduction to Flight Test Engineering
This is Research and Technology Organization (RTO) AGARDograph, RTO-AG-300-V14, by F. N. Stoliker; sponsored by SCI-172, the Flight Test Technical Team (FT3) of the Systems Concepts and Integration Panel (SCI) of the RTO, originally published in 1995, and reissued and re-formatted for electronic publication in July 2005. It presents a general introduction to the various activities and aspects of Flight Test Engineering that must be considered when planning, conducting, and reporting a flight test program. Its main intent is to provide a broad overview to the novice engineer or to other people who have a need to interface with specialists within the flight test community. The first two Sections provide some insight into the question of why flight test and give a short history of flight test engineering. Sections 3 through 10 deal with the preparation for flight testing. They provide guidance on the preliminary factors that must be considered; the composition of the test team; the logistic support requirements; the instrumentation and data processing requirements; the flight test plan; the associated preliminary ground tests; and last, but by no means least, discuss safety aspects. Sections 11 through 27 describe the various types of flight tests that are usually conducted during the development and certification of a new or modified aircraft type. Each Section offers a brief introduction to the topic under consideration, and the nature and the objectives of the tests to be conducted. It lists the test instrumentation (and, where appropriate, other test equipment and facilities) required, describes the test maneuvers to be executed, and indicates the way in which the test data is selected, analyzed, and presented. The various activities that should take place between test flights are presented next. Items that are covered are: who to debrief; what type of reports to send where: types of data analysis required for next flight; review of test data to make a comparison to predicted data and some courses of action if there is not good agreement; and comments on selecting the next test flight. The activities that must take place upon completion of the test program are presented. The types of reports and briefings that should take place and a discussion of some of the uses of the flight test data are covered. A brief forecast is presented of where present trends may be leading. Bibliographic details and an abstract are available in HTML format. The full text can be accessed online in PDF format from the RTO's web site.
Introduction to Flight Test Maneuvers
This web site, produced by the NASA Dryden Flight Research Center, provides detailed explanations and images of manoeuvres, flight test procedures, and how data is collected. The documents that comprise the Introduction to Flight Test Maneuvers are available in HTML and PDF formats. The content headings include: introduction; acceleration and deceleration; climb; pushover-pullup; roll; control pulses; flutter; maximum performance landing; maximum performance takeoff; sawtooth climb; speed; wind up turn; and steady sideslip.
Knowledge-Based Functions in Aerospace Systems
This is Research and Technology Organization (RTO) AGARD Lecture Series report, AGARD-LS-200, dated November 1995. In aerospace systems classical control technology has enabled the transfer of functions of the human operator to machines which need not be based on the explicit evaluation of knowledge. Symbolic data processing, neural networks and the techniques of artificial intelligence now permit the design of automatic systems which can explicity make use of knowledge stored in computers. The Lecture Series presents a conceptual framework for the automation of knowledge-based control and management functions in aerospace systems, which are usually carried out by human operators. It describes the structure of these functions, discusses successful examples of application and gives recommendations for further studies. For individual titles, see N96-18528 through N96-18533. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (44 Kb) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Linear Parameter-Varying Control of an F-16 Aircraft at High Angle of Attack
This is a North Carolina State University (NCSU), Department of Mechanical and Aerospace Engineering PhD dissertation, by Bei Lu, dated 1 October, 2004. It presents a study of advanced linear parameter-varying (LPV) control methodologies, with particular reference to applications of actuator saturation control and switching control, in order to improve the aircraft's capability at high angle of attack and expand the flight envelope. A standard two-step LPV antiwindup control scheme and a systematic switching LPV control approach are derived, and the advantages of LPV control techniques are demonstrated through nonlinear simulations of an F-16 longitudinal autopilot control system. Bibliographic and abstract details are available in HTML format. The full text of the document is accessible online in PDF format [1.01 Mb]. This title is part of North Carolina State University's Electronic Thesis and Dissertation (ETD) Collection
Low Takeoff Rotation Speed Commuter Type Aircraft Aerodynamic Performance of Type II and Type IV Fluids
This technical report (DOT/FAA/AR-03/47) was produced by the Aviation Research office of the Federal Aviation Administration (FAA) in August 2003 and was written by Arlene Beisswenger and Jean-Louis Laforte. Type II and Type IV aircraft ground anti-icing fluids are currently used on commuter type aircraft, although they are being certified to AMS1428 Annex B, which corresponds to aerodynamic acceptance test for large transport type jet aircraft whose takeoff rotation speeds generally exceed 100 to 110 knots. Some aircraft manufacturers have indicated certain performance adjustments or other commuter type operational procedures to be followed for selected aircraft when operators employ these Type II and IV fluids. At the request of the Federal Aviation Administration (FAA) William J. Hughes Technical Center, The Anti-icing Materials International Laboratory conducted AMS1428D Annex C Flat Plate Elimination Tests (FPET) for commuter type aircraft to ascertain their level of performance. The aerodynamic acceptance tests were conducted at three temperature intervals for two Type II fluids and three Type IV fluids in their neat, 75/25 and 50/50 dilution forms. A deicing and anti-icing fluid is considered acceptable at a test temperature if none of the independent boundary layer displacement thickness measurements are greater than the acceptance criteria defined by the military fluid that is tested simultaneously. The results showed that all the 50/50 dilutions are acceptable for the low-speed ramp down to minus 10 degrees Celsius, the lowest temperature tested due to freeze-point restriction. Three of the five 75/25 dilutions are acceptable for the low-speed ramp down to minus 10 degrees Celsius; below this temperature none of the fluids were acceptable. For the two other fluids, one was acceptable only at 0 degrees Celsius, the other was not acceptable at any temperature. For the fluids in their neat form, only one was acceptable at 0 degrees Celsius. For all the other fluids, the neat FPET results wer greater than the acceptance criteria. [Taken from abstract]. This is a PDF file, so Adobe Acrobat software will be required in order to read it.
Military Qualification of Fighter Aircraft in the Netherlands
This technical report (NLR-TP-2000-469) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2000 and was written by S. Storm van Leeuwen and Maj. T. Haringa. In the Netherlands a capability to qualify new stores for military aircraft exists. This capability consists of elements contributed by the Royal Netherlands Air Force (RNLAF) and the National Aerospace Laboratory NLR of the Netherlands. The RNLAF operates a fully instrumented F-16 Mid Life Update test aircraft. Currently running and envisaged programs are in the field of external store qualification and future avionics concept demonstration. Recently, a program to prove the airworthiness of two external store systems has been completed. The qualification procedure developed jointly by the RNLAF and NLR is described in general terms, together with the tailoring of the procedure to the airworthiness qualification program of external stores. Furthermore the analytical tools are described which are available at NLR and support the F-16 airworthiness qualification. Also, a short overview of the instrumented aircraft and its capabilities is given. The interaction of analytical tools (simulations) and the test aircraft (actual tests) in the program is emphasized. Results of the external store qualification program in the fields of flight handling, flutter/limit cycle oscillation behavior, stores separation, structural strength in general and ventral fin issues in particular are given. It is concluded that a unique infrastructure, consisting of analytical tools, procedures, test facilities, and last but certainly not least, skilled people, is available to support the RNLAF in their aircraft operations. [Taken from abstract]. The full text is available as a PDF file.
MOSAIC : Model-Oriented Software Automatic Interface Converter
This technical report (NLR-TP-2000-571) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2000 and was written by W. F. Lammen, A. A. ten Dam, W. M. M. Heesbeen and R. Franco. A typical requirement on simulation models, being software application components that need to interact with other simulation components, is compliance with interface standards. One of the challenges of the international simulation community is to enable simulation models to run in any simulation tool, independent of which tool was used for model creation. In aerospace industry simulation models are often developed with Commercial Off-The-Shelf (COTS) tools like MATLAB(r)/ Simulink(r) / Stateflow(r), MATRIXx(r) and Statemate(r). Transfer from a COTS tool to another simulation environment may require time-consuming adjustment of the simulation model by the model developer. The National Aerospace Laboratory NLR has developed for ESA/ESTEC the Model-Oriented Software Automatic Interface Converter (MOSAIC) tool. MOSAIC automatically transfers simulation models from MATLAB/Simulink to the real-time simulation tool EuroSim. It has been experienced that automatic model transfer with MOSAIC significantly reduces time, cost, effort and error-prone source code editing. [Taken from abstract]. The full text is available as a PDF file.
NATO Research and Technology Organization (RTO) : Full Text Publication Library
The web site provides access to a collection of full text documents produced by the NATO Research and Technology Organization and its predecessor, Advisory Group for Aerospace Research & Development (AGARD). The collection includes the following report series: RTO-AG (Advanced Guidance for Alliance Research and Development); RTO-MP (Meeting Proceedings);RTO-EN (Education Notes); RTO-TR (Technical Reports); RTO-TM (Technical Memoranda); RTO-Misc (Miscellaneous Publications); AGARD-AG (AGARDographs); AGARD-R (Reports); AGARD-AR (Advisory Reports); AGARD-CP (Conference Proceedings); AGARD-LS (Lecture Series); and AGARD-Misc (Miscellaneous Publications). The browse facilityprovides access to abstracts, Tables-Of-Contents and Full Text. Currently the search option is under construction.
New Analysis Techniques for Clearance of Flight Control Laws. An Overview of GARTEUR Flight Mechanics Action Group 11
This technical report (NLR-TP-2004-147) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2004 and was written by M. Selier, C. Fielding, U. Korte and R. Luckner. Between April 1999 and September 2002, GARTEUR Flight Mechanics Action Group 11 FM(AG11) conducted research on â€˜New Analysis Techniques for the Clearance of Flight Control Lawsâ€™. To disseminate the results, a book was written and a special session on control law clearance has been organised for the AIAA Guidance Navigation and Control conference, August 2003. This report is based on a paper that served as an introduction for the other presentations in the special session. It explains the importance of the clearance task and it describes the application of five new analysis techniques to a benchmark clearance problem, with the objective of improving the efficiency of the clearance process. The techniques considered were Î¼-analysis, Î½-gap analysis, a polynomial-based clearance method, a bifurcation and continuation method and an optimisation-based clearance. The main results, an industrial view and the conclusions and recommendations of the group are given. [Taken from abstract]. This is a PDF file, so Adobe Acrobat software will be required in order to read it.
Numerical Simulations of the Aeroelastic Response of an Actively Controlled Flexible Wing
This web site provides access to a Virginia Polytechnic Institute and State University MSc thesis, by Benjamin D. Hall, June 24, 1999. The thesis describes a numerical simulation for evaluating methods of predicting and controlling the response of an elastic wing in an airstream. The thesis is made available as part of Virginia Tech's digital library and archives collection. An abstract is available in HTML format, and the full text can be accessed online in PDF format.
On a Farkas Lemma for a Class of Constrained Dynamical Systems
This technical report (NLR-TP-2002-472) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2002 and was written by A. A. ten Dam. Many aerospace systems with operational and environmental restrictions are examples of constrained dynamical systems. Mathematical models of constrained dynamical systems usually consist of a combination of equalities and inequalities. In this report some examples are presented to illustrate this fact. Some of the results obtained and difficulties encountered in our research towards a generalisation of a result first derived by Farkas in 1895 are presented. Such a novel Farkas Lemma is necessary in order to arrive at a systematic approach to deriving efficient representations of constrained dynamical systems. [Taken from abstract]. The full text is available as a PDF file.
This is Research and Technology Organization (RTO) AGARD-AR-314, dated April 1994. From previous AGARD activities, it was recognized that flying qualities and traditional aircraft performance parameters did not characterize the capability or effectiveness of combat aircraft, although they do offer a guide. Other expert groups had reached a similar conclusion. The subject that arose from these realizations was 'agility'. Recognizing that this was an incomplete or immature concept and that a wide variety of sometimes disparate views existed, the Flight Mechanics Panel formed a further Working Group, WG 19, consisting of specialists from AGARD member countries, to study the subject under the title of 'Operational Agility'. Working sessions were held at places of special interest to the group, between 1991 and 1993. The specific aims of the Working Group were to provide definitions, which are universally acceptable, of the terminologies involved in agility; to collate the results of lessons learned from experiments on agility; to define metrics or figures of merit for use in design and evaluation; to explore and document the theoretical foundations; to explore the operational pay-off of balanced capabilities between the airframe, systems and weapons; to highlight any specialized aspects applicable to rotorcraft; to indicate possible means of evaluation in flight; and to recommend areas for further research and development activities, including possible collaborative projects. The Group has completed its study of operational agility with this report. In undertaking the study, a greater understanding has been reached of those subjects which influence operational agility and how these subjects, via the use of operational agility concepts, may be related to the combat effectiveness of the weapon systems. In reaching this understanding, the Group has proposed definitions of the agility terminology which should prove universally acceptable; it has arrived at the methodology for assessment of the various component systems which contribute to the operational agility or combat effectiveness of a Weapon System; and has listed a number of major conclusions and recommendations. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (28.56MB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Outer-Loop Control in Asymmetrical Trimmed Flight Conditions
This is the full text of a thesis by Gary D. Miller which was presented to the Air Force Institute of Technology (AFIT) in 2004. Traditionally flight control systems have used linearized equations of motion solved around a single trim point. This thesis proposes a nested-loop controller directly solved from the equations of motion. The control equations were developed as a solution to asymmetrically trimmed flight conditions. A two-loop design was proposed for the controller. The outer loop modeled the aircraft as a point mass and all forces were balanced to find the aircraft states. The equations input the control variables and output the aircraft states. The inner-loop utilizes the six-degree of freedom model of the aircraft to solve the moment equations. With the input states, the required control surface deflections are calculated. The control equations were investigated for typical flight conditions to find the predicted aircraft control settings. The control equations were implemented using aeromodel data for a Learjet-25. The aeromodel data was updated in flight test. The predictions from the control equations were then compared to flight test results. The model was able to predict the required elevator deflection for simple longitudinal cases in level and climbing flight to within tolerances. The simple lateral-directional cases were not as accurate as the longitudinal investigations. As complex maneuvers were investigated, the model predictions did not match the flight test results. The complex maneuvers were not reproduced in flight test to match the flight parameters calculated with the model. Also the lateral-directional stability derivatives and measurements had larger errors than the longitudinal variables. [Taken from abstract]. The full text of the thesis is available in PDF format and is provided by the Air University ResearchWeb site.
Parametric Study of the Towline Shape of an Aircraft Decoy
This is the full text of a Master's thesis by Ensign Tyler L. Richardson, USNR, AFIT/GAE/ENY/05-J08, which was presented to the Faculty Department of Aeronautics and Astronautics of Air University's Air Force Institute of Technology (AFIT), in June 2005. Some of today's aircraft use decoys as a defense against enemy weapons. The decoy is towed behind the aircraft with the intention of attracting the weapon propagator by deception, trying to mislead the weapon into detecting it instead of the aircraft. An aircraft deploys a decoy via a towline extending out behind and below the aircraft. However, during some maneuvers, the towline moves up into the jet exhaust plume of the aircraft. The high temperatures of the exhaust can cause damage to the towline cable, ranging from disrupting data flow between the decoy and aircraft to severing the towline altogether. This research modeled the system to determine the towline shape and position relative to the aircraft under steady state conditions. Non-dimensional parameters were used to investigate what parameter groups affect the motion of the towline, reducing the steady state solution space from 7 parameters to 2 parameters. The effects of both parameter groups in determining the shape of the towline are presented. The author provides recommendations for preventing the towline from entering the jet exhaust during straight and level flight. [Taken from abstract]. The full text is available in PDF format on the Scientific and Technical Information Network (STINET) which is provided by the Defense Technical Information Center (DTIC).
Persistent and Critical Issues in the Nation’s Aviation and Aeronautics Enterprise
This report was released by the Aerospace Division of the American Society of Mechanical Engineers (ASME), Washington, DC, November 2003. A Steering Committee consisting of members of key United States engineering and aerospace associations was asked by the Office of Science and Technology Policy (OSTP) to provide the engineering community's perspective on prioritizing technologies critical to the long-term health of the nations's civil and military aviation and aeronautics technology enterprise. This statement summarises the Steering Committee’s findings and recommendations. It includes an overview of cross-cutting technology and policy issues, as well as individual sections covering aerodynamics, aircraft propulsion, avionics and embedded information technology, flight mechanics and control, information technology in design, and structures and materials. The text is available in PDF format. Useful tables and figures include Uninhabited Air Vehicles (UAV) Project Count, by Country of Development; National Aeronautics and Space Administration Aeronautics R&T Funding; U.S. Department of Defense Aeronautics R&T Funding; Aerospace Engineering Degrees Awarded; Graduate Degrees In Aeronautical Engineering, U.S. and Foreign; and a List of Recent X-plane Prototype Programmes.
Perspectives of NLR Aeroelastic Methods to Predict Wing/Store Flutter and Dynamic Loads of Fighter-Type Aircraft
This technical report (NLR-TP-2000-447) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2000 and was written by B. J. G. Eussen, M. H. L. Hounjet, J. J. Meijer, B. B. Prananta and I. W. Tjatra. This paper presents an overview of available aeroelastic methods and the current developments at NLR. The methods for routine flutter prediction are based on the classical linear approach using linear unsteady aerodynamic forces. At some conditions it is found necessary to model nonlinear effects e.g. prediction of limit cycle of oscillations, in which a method based on semi-empirical techniques is employed. To cope with continuously more challenging requirements in the prediction of aeroelastic characteristics, current developments at NLR concentrate on the computational aeroelastic simulation using CFD methods. Relatively mature methods employ potential-flow modelling, while a system with a fluid-structure interaction model and based on the time accurate Euler/Reynolds-Averaged Navier-Stokes equations is currently under development. [Taken from abstract]. The full text is available as a PDF file.
Prediction of Pilot-Induced Oscillations (PIO) due to Actuator Rate Limiting Using the Open-Loop Onset Point (OLOP) Criterion
The site provides access to an Air University, Air Force Institute of Technology, Graduate School of Engineering and Management, MSc Thesis, by Captain Gregory P. Gilbreath, USAF, AFIT/GA/ENY/01M-02, dated March 2001. The thesis presents an examination of the Open-Loop Onset Point (OLOP) criterion, developed by DLR German Aerospace, to see if it could accurately predict PIO due to actuator rate limiting and to evaluate its potential as a design tool. Citation details and an abstract are available in HTML format. The full text can be accessed in PDF format. The document is part of the Air University Research Database
Pressure and Flow Measurement
This is Research and Technology Organization (RTO) AGARD-AG-160-11, dated July 1980. This AGARDograph is the 11th of the AGARD Flight Test Instrumentation Series, and discusses the fundamentals of pressure and flow measurement from the viewpoint of flight test instrumentation. The evolution of flight test instrumentation systems during the last decade reflects the radical changes in electronic measuring techniques. Nevertheless, the basic principles of measurement methods are essentially unchanged and the sensors for pressure and flow measurements have experienced only slight changes. An overview of modern instrumentation is given with important applications to altitude measurement, vertical and horizontal speed measurement, boundary layer, wake and engine flow measurement. The scope of this AGARDograph is to give self consistent information on the different techniques and systems and to give references for a more detailed study of special techniques. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (597KB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Robust Integrated Control System Design Methods for 21st Century Military Applications
This is a NATO Research and Technology Organization (RTO) report RTO-EN-SCI-142, October 2004. This was prepared by The Systems Concepts and Integration Panel (SCI) to support a Lecture Series presented presented on 12-13 May 2003 in Forlì, Italy; 15-16 May 2003 in Setubal, Portugal; and 29-30 May 2003 in Los Angeles, USA. During recent years, guidance and control system design engineers have indicated a growing need to “Bridge the Gap” between theory and the real world considerations, in developing viable cost-effective control system designs for a broad range of anticipated future military applications. Furthermore future control systems will in general, involve highly innovative configurations and system technologies that will have an impact on increasing the cost and the time required to achieve a successful design. This series of lectures is intended to help control engineers to bridge the gap between theory and applications. The cost and time involved in designing a modern 21st century control system is also addressed. The citation and abstract information are in HTML format, and the full text is available online in PDF format.
See How It Flies: A New Spin on the Perceptions, Procedures, and Principles of Flight
This resource is a full text electronic textbook, written by John S. Denker, a pilot. The book is intended to appeal to pilots and anyone else who is interested in how aeroplanes behave. The idea is to concentrate on ideas that are useful in the cockpit, and to explain them as clearly as possible. The main topics are perceptions, procedures and principles. The book is available in HTML format and is broken down into chapters and subsequently into headings to aid browsing.
Simulation And Analysis Of Wing Rock Physics For A Generic Fighter Model With Three Degrees-Of-Freedom
The site provides access to an Air University, Air Force Institute of Technology, Graduate School of Engineering and Management, PhD Dissertation, by Major Ahmed A. Saad, Egyptian Air Force, AFIT/DS/ENY/00-01, dated July 2000. The thesis presents a computational simulation of wing rock in three degrees of freedom: roll, sideslip, and vertical motion to study the effect of adding the sideslip and vertical motion. The results are for a generic fighter model consisting of a fore-body, a cropped delta wing, and a vertical fin. The effect of including the vertical fin is also studied. Citation details and an abstract are available in HTML format. The full text can be accessed in PDF format. The document is part of the Air University Research Database.
Simulation of Limit Cycle Oscillation of Fighter Aircraft at Moderate Angle of Attack
This technical report (NLR-TP-2003-526) was published by NLR (the National Aerospace Laboratory of the Netherlands) in 2004 and was written by B.B. Prananta, J.C. Kok, S.P. Spekreijse, M.H.L. Hounjet and J.J. Meijer. In this paper recent NLR research on transonic limit cycle oscillations of fighter aircraft configurations is reported. Focus is on modelling the dynamic non-linearity of the aerodynamics. Computational aeroelastic simulations of fighter aircraft configurations subjected to complex transonic flow conditions including flow separation are discussed. Important details of the simulation method are highlighted. The simulation method is first applied to standard test cases for limit cycle oscillations due to shock motion (ISOGAI test case) and shock induced flow separation (DLR test case). Finally, the capability of the simulation method to capture limit cycle oscillations of an F-16 aircraft in heavy store configuration and at moderate angles of attack in transonic flow is demonstrated. The obtained results confirm the role of shock-induced flow separations as one of the possible causes of limit cycle oscillations for specific fighter aircraft configurations. [Taken from abstract]. The full text is available as a PDF file.
Society of Experimental Test Pilots
The mission statement of The Society of Experimental Test Pilots (SETP), is to be the recognized world leader in promoting safety, communication and education in the design and flight test of aerospace vehicles and their related systems, and, to maintain a viable professional and prestigious international society for all test pilots and aerospace corporations. The SETP site provides access to a range of information resources including: a brief history of the Society, coverage of Section activities, and details of forthcoming events and employment opportunities. The site also provides access to the SETP's quarterly journal, Cockpit Magazine (for members only).
Society of Flight Test Engineers Online Symposium Paper Search
The Society of Flight Test Engineers (SFTE) is a fraternity of engineers, whose principal professional interest is the flight testing of aircraft and missiles. This web page facilitates access to citations and abstracts of SFTE symposium papers. Papers can be listed by title, or can be retrieved using a keyword search (symposium number, paper number, paper title, author, affiliation, abstract, report year). There is an online ordering facility, based on credit card payments, for the full-text papers.
Society of Flight Test Engineers
The Society of Flight Test Engineers (SFTE) is a fraternity of engineers, whose principal professional interest is the flight testing of aircraft and missiles. The objective of the Society is the advancement of flight test engineering throughout the aircraft industry by providing technical and fraternal communication among individuals, both domestic and international, in the allied engineering fields of test operations, analysis, instrumentation and data systems. The SFTE web site provides a range of information resources incliding: a calender of events, links to SFTE Chapters, job announcements, workshops and details of the SFTE Technical Council. The current issue of the Society's newsletter, SFTE Flight Test News, is available for downloading. A database containing citations and abstracts of SFTE symposium papers can be browsed or searched, and papers can be ordered online.
Stability in Aerospace Systems
This is Research and Technology Organization (RTO) AGARD-R-789, dated February 1993. This volume contains the 18 unclassified papers presented at the Guidance and Control Panel Workshop. The presented papers cover topics under the following headings: fundamental aspects of stability with examples; basic theoretical aspects and chaos; and applications of aerospace techniques. For individual titles, see N94-11490 through N94-11504. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (53.52MB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Standard Coordinate Systems for Reporting the Mass Properties of Flight Vehicles - Society of Allied Weight Engineers Recommended Practice 6
The intent of Society of Allied Weight Engineers (SAWE) Recommended practice 6A, is to reduce errors and costs associated with improperly defined coordinate axis systems. The standard is intended to assist mass properties engineeers in their discussions with flight dynamics engineers and others at an early stage of flight vehicle design. The document was prepared by the SAWE Government-Industy Workshop. It was issued in 1995, and revised in September 1999. This is a PDF document.
Stick and Feel System Design
This is Research and Technology Organization (RTO) AGARDograph, RTO-AG-332, authored by J.C. Gibson and R.A. Hess; sponsored by the Flight Vehicle Integration Panel of AGARD, dated March 1997. The report explains; Since the earliest days of manned flight, designers have to sought to assist the pilot in the performance of tasks by using stick and feel systems to bring these tasks within the bounds of human physical capabilities. This volume describes stick and feel systems in two parts. Part one describes the technologies which have been developed throughout the history of 20th Century aviation. Part two describes how modern systems dynamics interact with the human pilot. It is hoped that the design lessons and approaches outlined in this volume will contribute to a better understanding and appreciation of the importance of force-feel system design in aircraft/rotorcraft flight control. Bibliographic details and an abstract are available in HTML format. The full text can be accessed online in PDF format (7 Mb) from the RTO's web site.
Structural Aspects of Flexible Aircraft Control
This web site provides access to a NATO Research and Technology Organization (RTO) document titled: Structural Aspects of Flexible Aircraft Control, proceedings of the Specialists Meeting of the RTO Applied Vehicle Technology Panel (AVT), held in Ottawa, Canada, 18-20 October 1999, RTO-MP-036, May 2000. The report contains 26 papers and a keynote address that address design issues and more specifically structural aspects of flexible aircraft control. There were three sessions covering the following topics: Aeroservoelasticity; Active Control of Flexible Structure I; and Active Control of Flexible Structure II. Citation and abstract details are in HTML format, and the full text is available online in PDF format (35.8 Mbytes).
Structures and materials panel working group 27 on evaluation of loads from operational flight maneuvers
This is Research and Technology Organization (RTO) AGARD Advisory Report, AGARD-AR-340, dated April 1996. It was sponsored by the Advisory Group for Aerospace Research and Development. This Report describes an evaluation of a method to derive loads from operational flight maneuvers. The basic assumption of this method is that all operational maneuvers performed in service can be verified as a set of Standard Maneuvers (normalized parameter time histories for each independent maneuver type). The verification of Standard Maneuvers is based on recordings of relevant maneuver parameters in service and for new tactics/missions on special flights or simulations. The initial evaluation of the concept done by the Working Group (WG.27) has demonstrated the feasibility of determining loads from operational flight maneuvers. Bibliographic details and an abstract are available in HTML format and the full text is available in PDF format (12.5 Mb)from the RTO's web site.
Symposium on Advanced Flow Management
This site provides access to a Research and Technology Organization Meeting Proceedings, RTO-MP-069 (I), Paris, March 2003. The document contains papers presented at the Symposium of the RTO Applied Vehicle Technology Panel (AVT) Specialists’ Meeting held in Loen, Norway, 7-11 May 2001. Part A contains forty eight papers from a symposium on Vortex Flows and High Angle of Attack for Military Vehicles. Part B of the report contains papers from a separate and distinct symposium on Heat Transfer and Cooling in Propulsion and Power Systems, which was held concurrently. A table of contents, and the full text (157 Mbytes) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
System Identification for Integrated Aircraft Development and Flight Testing
This web site provides access to a Research and Technology Organization Meeting Proceedings, RTO-MP-011, Paris, March 1999. The document contains papers presented at the the Systems Concepts and Integration Panel (SCI) Symposium held in Madrid, Spain, 5-7 May 1998. The objectives of the symposium were to review the state-of-the-art of flight vehicle system identification, and to provide a critical appraisal of current methods developed and applied to flight test data in a number of NATO countries. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (35.6 Mbytes) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library
Technologies for Highly Manoeuvrable Aircraft
This is Research and Technology Organization (RTO) AGARD-CP-548, dated March 1994. The new generation of combat aircraft incorporate significant advances in maneuver capability, especially in such areas as post-stall control and sustained supersonic maneuver. These technologies expand the operational capabilities, and are essential for survival in a sophisticated threat scenario, and also to obtain favorable exchange ratios against an opponent using the current generation of fighters. The aim of this symposium was to review the various technologies, which combine to give this increased operational capability, and the techniques which are available or being developed, to overcome the design problems associated with the attainment of these goals. The symposium was divided into six sessions covering propulsion and integrated flight control, aerodynamics and control at high angles of attack, post-stall flight and control, flying qualities applied criteria, agility and simulation. For individual titles, see N94-34606 through N94-34631. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (88.29 MB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Temporary Installation Methods for PAPI/A-PAPI Systems : Final Report
This provides access to a Federal Aviation Administration (FAA) report, DOT/FAA/AR-01/111, by Keith Bagot, dated January 2002. Airports have a need to temporarily install a precision approach path indicator (PAPI) or an abbreviated PAPI (A-PAPI) to provide accurate approach slope guidance when a runway threshold is temporarily displaced due to construction or maintenance projects. Airports have been reluctant to pour concrete foundations for temporary installations because of the cost and impact on operations. However, since the vertical alignment of the PAPI system is critical, a temporary installation method must take into consideration the need for enough rigidity and stability to maintain the proper aiming angles without excessive field monitoring. This report describes three temporary installation methods that were effective in maintaining proper aiming angles within the Federal Aviation Administration Advisory Circular 150/5345-28 limitations. The full text of the report is available in PDF format, from the online catalogue of the FAA William J. Hughes Technical Center Library.
Test and Evaluation Trends and Costs for Aircraft and Guided Weapons
This technical report (MG-109-AF) was published by The RAND Corporation in 2004 and was written by Bernard Fox, Michael Boito, John C. Graser and Obaid Younossi. Over the past 20 years, various approaches have been proposed to reduce the cost and duration of testing military systems. At the same time, the systems being tested have become considerably more complex. This study examined system-level testing for selected fixed-wing aircraft programs and related weapons. The authors provide cost estimating methodologies and reference information on various test programs. [Taken from abstract]. This is a PDF file, so Adobe Acrobat software will be required in order to read it.
The testing of fixed wing tanker and receiver aircraft to establish their air-to-air refuelling capabilities
This is Research and Technology Organization (RTO) AGARD-AG-300-VOL-11, dated December 1992. Since its founding in 1952, the Advisory Group for Aerospace Research and Development has published, through the Flight Mechanics Panel, a number of standard texts in the field of flight testing. The original Flight Test Manual was published in the years of 1954 to 1956. The Manual was divided into four volumes: (1) performance; (2) stability and control; (3) instrumentation catalog; and (4) instrumentation systems. This AGARDograph therefore describes the points that need to be considered when planning AAR trials to clear a new tanker or a new receiver aircraft for Service use. The paper assumes some familiarity with current AAR practices and equipment. It covers the two AAR systems in widespread use, namely the probe and drogue, and boom refuelling systems. Many of the points that need to be considered are common to both. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text (4.50MB) of the document can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Time-Domain Simulations of Aerodynamic Forces on Three-Dimensional Configurations, Unstable Aeroelastic Responses, and Control by Neural Network Systems
This is a Virginia Polytechnic Institute and State University Department of Engineering Science and Mechanics PhD dissertation, by Zhicun Wang, dated May 7, 2004. In this study the nonlinear interactions between aerodynamic forces and wing structures are numerically investigated as integrated dynamic systems, including structural models, aerodynamics, and control systems, in the time domain. An elastic beam model coupled with rigid-body rotation is developed for the wing structure, and the natural frequencies and mode shapes are found by the finite-element method. A general unsteady vortex-lattice method is used to provide aerodynamic forces. This method is verified by comparing the numerical solutions with the experimental results for several cases; and thereafter applied to several applications such as the inboard-wing/twin-fuselage configuration, and formation flights. Flutter analysis is carried out for a High-Altitude-Long-Endurance aircraft wing cantilevered from the wall of the wind tunnel, a full-span wing mounted on a free-to-roll sting at its mid-span without and with a center mass (fuselage). In addition, a predictive control technique based on neural networks is investigated to suppress flutter oscillations. Bibliographic and abstract details are available in HTML format. The full text of the document is accessible online in PDF format [5.11 Mb]. This title is part of Virginia Tech’s Electronic Thesis and Dissertation Collection (VT ETD)
Touchdown : The Development of Propulsion Controlled Aircraft at NASA Dryden
The web site provides access to a NASA Dryden Flight Research Center history series publication, by Tom Tucker. It tells the story of the Propulsion Controlled Aircraft project, and how a NASA-industry team developed a way to land an aircraft safely using only engine thrust to control the aircraft. The full text of the publication is available online in HTML format.
University of Glasgow : Department of Aerospace Engineering
This is the home page of the research groups of the Department of Aerospace Engineering at the University of Glasgow. Each of the six groups provides background information about its activities and interests including research projects currently being undertaken. Research is based around six core areas - flight dynamics, computational fluid dynamics (CFD), space systems engineering, air traffic management and avionics, low speed aerodynamics and design and structures.
University of Maryland: Alfred Gessow Rotorcraft Center
The Alfred Gessow Rotorcraft Center (AGRC) at the University of Maryland is one of three rotorcraft centers of excellence established by the Army Research Office (ARO) in 1982. The site provides access to a range of information including: news items, a list of the faculty and their research interests, and a description of the Center's facilities. The research interests of the Center include: rotor dynamics and smart structures; aerodynamics, active and passive damping control of smart structures; damage detection and health monitoring; CFD and acoustics; flight mechanics and controls; and composite structures. References to staff research papers are listed under some of the research sections. the website also as link to the award winning design of the AHS annual student design competion.
Verification and Validation Data for Computational Unsteady Aerodynamics
This web site provides access to a Research and Technology Organization technical report, RTO-TR-026, dated October 2000. The report was sponsored by the RTO's Applied Vehicle Technology Panel (AVT). The report aims to collect reliable experimental data on unsteady aerodynamics and present them in a form which permits use for verification of codes. The data categories include: flutter, buffet, stability and control, dynamic stall, cavity flows and store separation. The reports also includes computational solutions. Bibliographic and abstract details are available in HTML format. A table of contents, and the full text of the document (32 Mbytes) can be accessed online in PDF format. The document is contained in the RTO's Full Text Publication Library.
Vertical Impact Response Charateristics of Four Commuter/Regional Airplanes
This provides access to a Federal Aviation Administration (FAA) technical report DOT/FAA/AR-08/20 written by Allan Abramowitz and Tong Vu dated September 2008. A narrow-body transport airplane fuselage section was subjected to a vertical impact drop test at the Federal Aviation Administration (FAA) William J. Hughes Technical Center located at the Atlantic City International Airport, New Jersey. The objective of the test was to determine the interaction between a typical transport airplane fuselage, particularly its floor structure, and a conformable auxiliary fuel tank under severe, but survivable, impact conditions. The fuel tank used in this test is representative of tanks being installed in narrow-body transport airplanes. A 10-foot airframe section from a Boeing 737-200 airplane was dropped from a height of 14 feet, generating a vertical impact velocity of 30 ft/sec. The airframe test section, at a weight of 8780 pounds, simulated the load density at the maximum takeoff weight condition. The weight included cabin seats, dummy occupants, and simulated fuel in the 500-gallon fuel tank. Structural response data were obtained during the impact from instrumentation installed on the fuselage structure, floor structure, and the fuel tank. The fuselage test section sustained severe damage after the test. Portions of the cabin floor were damaged due to the impact with the auxiliary fuel tank located in the cargo compartment. The bottom of the fuel tank was punctured in numerous locations resulting in fuel spillage. The strength and rigidity of the fuel tank limited the inherent ability of the fuselage structure to absorb energy crushing during the impact. [Taken from abstract]. The full text is available in PDF format so Adobe Acrobat software is required in order to read it.
Virginia Tech Dynamics and Control Research
This site provides information on flight dynamics and control research activities at Virginia Polytechnic Institute and State University. Research topics include: total envelope aircraft dynamics and control; control allocation, control allocation toolbox control power requirements study; unified PIO analysis; and control system requirements for multidisciplinary design. There is a section on journal and conference papers produced by staff and students. Some of the papers have citations only, others have abstracts, and some are in full text.
Wright Air Development Center Digital Collection
Wright-Patterson Air Force Base has been a major centre of aeronautical and aeorspace design and development for many years. The purpose of this site is to document various aspects of the Wright Air Development Center (WADC) period in this long history. The site, which is hosted by the Galvin Library at Illinois Institue of Technology, provides access to a range of information resources. The history section includes a timeline of important events; image gallery, an overview of WADC's association with Illinois Institute of Technology; and features on the Center's involvement in both the "space race" and the Roswell incident. The reference shelf contains a linked bibliography of historical sources relating to the Wright Air Development Center. Some of these publications, such as, Birthplace, Home and Future of Aerospace... The Evolution of Aeronautical Development at the Aeronautical Systems Center, are available in full text (pdf format). The Digital Collection provides access to WADC technical report information. The collection can be browsed by report number, date, author or corporate author. Many of the reports are available in full text. A full bibliography of reports is also available in pdf, MS Excel, or interactive (requires Internet Explorer v. 4.01 and Microsoft Office Web Components) formats.
X-15 First Flight 30th Anniversary Celebration
Proceedings of the X-15 First Flight 30th Anniversary Celebration, NASA Conference Publication 3105; Proceedings of an anniversary celebration held at NASA Ames Research Center, Dryden Flight Research Facility, Edwards, California June 8, 1989. These proceedings include comments by historians, pilots, and others with keen insights on the historic X-15 program that bridged aeronautics with astronautics during NASA's first decade. The full-text of the papers are available in HTML format.
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