50,299 research outputs found
Capital flight and war
No full textThe author provides empirical evidence on the effects of inflation on post-war capital flight flows. He tests the hypothesis that inflation has a positive additional impact on capital flight flows after war. He uses a new panel dataset of 77 developing countries, of which 35 experienced at least one episode of war between 1971 and 2000. The author uses a range of estimation methods and four capital flight measures-Cline, World Bank Residual, Morgan Guarantee, and Dooley. The results consistently support the research hypothesis: Post-war inflation increases annual capital flight flows by about 0.005 to 0.01 percentage points of GDP. This effect is substantial in total at high inflation rates. The implication is that low inflation helps to curb capital flight in post-conflict economies.Economic Theory&Research,Banks&Banking Reform,Investment and Investment Climate,Settlement of Investment Disputes,Achieving Shared Growth
Flight test: Supporting the investigation of factors affecting loss of control of light aircraft
No full textA quarter of all fatal General Aviation accidents in the UK during the period 1980 to 2006 involved Loss of Control (LoC) in Visual Meteorological Conditions (VMC). LoC has consistently appeared in accident statistics over this period, but at apparently different rates for different aircraft types. This raises two important questions - why do these LoC events happen and why is there a difference between aircraft types?.
One case in point is that of the Cessna 150 /152 and over the 27-year period
analysed, the Cessna 150 falls approximately on the average for fatal accidents in the UK GA fleet, whereas the Cessna 152 exhibits a lower accident rate. Brunel Flight Safety Laboratory, in conjunction with the UK
General Aviation Safety Council, undertook to try and understand why this is
so. The key design differences in relation to performance and handling qualities were researched using available published material and informal interviews with type-experienced students, pilots and flying instructors.
A flight test programme was conducted using examples of both aircraft types to gather additional research data, to assess and compare the apparent performance and handling qualities (both qualitatively and quantitatively). Flight tests were performed at three different CG conditions relevant to the key design differences, concentrating upon apparent longitudinal (static and dynamic) stability and control characteristics, stall and low-speed handling
characteristics, and cockpit ergonomics / pilot workload. In all tests, normal
(unmodified) flying club aircraft were used, in most cases with a 2-man (TP+FTE) crew. Data was recorded manually on test cards and
automatically using a low-cost, commercially available, portable FDR.
Proven theory was used to estimate static margins and pilot stick forces and gradients in the region of the stall, the pre-cursor to an LoC event.General Aviation Safety Council (GASCo
Loss of control testing of light aircraft and a cost effective approach to flight test
No full textCopyright @ The Society of Flight Test EngineersLoss of control in Visual Meteorological Conditions (VMC) is the most common cause of
fatal accidents involving light aircraft in the UK and probably worldwide. Understanding
why LoC events occur and why there are apparent differences between aircraft types is currently under investigation by Brunel Flight Safety Laboratory (BFSL). Using a case study approach for selected light aircraft used in the training environment
and based upon a 29 year study of UK fatal accidents, BFSL undertook a qualitative and
quantitative review of fatal stall/spin accidents using a combination of statistical and qualitative analysis. Aircraft/model design differences and published material were reviewed with respect to performance and handling qualities for possible clues, and informal interviews were conducted with type-experienced students, pilots and flying
instructors. A flight test programme was executed using multiple examples (for fleet-wide attributes) of aircraft models to enable assessment and comparison of flying qualities (both qualitatively and quantitatively). Working within the continuous budget constraints of academia, a creative and cost effective flight test programme was developed without compromising safety. The two-man team (TP & FTE) used standard (unmodified) flying club and syndicate aircraft in conjunction with non-invasive low cost flight test instrumentation. Tests included apparent longitudinal (static and dynamic) stability and control characteristics, stall and low-speed handling characteristics and cockpit
ergonomics / pilot workload. During this programme, adaptations were also made to the
classic Cooper-Harper “point tracking” method towards a “boundary avoidance” method.
The paper describes tools and techniques used, research findings, the team's lessons
learned and proposed future research. It also discusses the possible application of
research results in aircraft, pilot and environmental causal factors, enabling a better understanding of LoC incidents and future avoidance within the light aircraft community.Financial support from the Thomas Gerald Gray Charitable Trust Research Scholarship Scheme was used in this study
A syntax of hoverfly flight prototypes
No full textGeurten B, Kern R, Braun E, Egelhaaf M. A syntax of hoverfly flight prototypes. Journal of Experimental Biology. 2010;213(14):2461-2475.Hoverflies such as Eristalis tenax Linnaeus are known for their distinctive flight style. They can hover on the same spot for several seconds and then burst into movement in apparently any possible direction. In order to determine a quantitative and structured description of complex flight manoeuvres, we searched for a set of repeatedly occurring prototypical movements (PMs) and a set of rules for their ordering. PMs were identified by applying clustering algorithms to the translational and rotational velocities of the body of Eristalis during free-flight sequences. This approach led to nine stable and reliable PMs, and thus provided a tremendous reduction in the complexity of behavioural description. This set of PMs together with the probabilities of transition between them constitute a syntactical description of flight behaviour. The PMs themselves can be roughly segregated into fast rotational turns (saccades) and a variety of distinct translational movements (intersaccadic intervals). We interpret this segregation as reflecting an active sensing strategy which facilitates the extraction of spatial information from retinal image displacements. Detailed analysis of saccades shows that they are performed around all rotational axes individually and in all possible combinations. We found the probability of occurrence of a given saccade type to depend on parameters such as the angle between the long body axis and the direction of flight
Scheduling and routing models for airline systems
No full textDecember 1969PB 196 528Includes bibliographical referencesForeword: This report attempts to put together all of the optimal computer models concerned with scheduling and routing problems for passenger transportation systems. By placing them in one place, classifying them, and using a consistent notation, it is hoped that the models' relationships to each other can be seen, and that a clear picture of the state of the art in model building and solving can be shown. The emphasis of the report is on optimal models which use well-known optimization techniques from mathematical programming. Work which uses heuristic computer methods in this area is quite extensive, but is not described here. The models are oriented towards public transportation systems operati-ng on a short haul network. Generally a cyclic or repetitive schedule of services is assumed, and a single vehicle rather than a train of vehicles is being dispatched. Within those assumptions, the models can find applicability to schedule planning for a wide range of public transportation systems, not necessarily just airline systems. The research is supported in part by the Office of High Speed Ground Transportation, Department of Transportation, and is pointed towards producing schedules for both high speed trains and future V/STOL aircraft. The models are useful to planners and regulators in studying problems in corporate planning, in transportation systems planning, and in regulation of transportation industries. An extensive bibliography accompanies each class of models in this report. If it is not complete (with respect to optimal models), I would appreciate receiving additional references from interested readers. One of the reasons for writing this report is to give a good bibliography for various groups of present researchers who seem to be unaware of segments of the literature, or of each other's activities. Much of the content of this report has been taken from lecture notes prepared by the author for an MIT graduate course, "Flight Transportation Operations Analysis", given by the author for the past few years. Students from that course will recognize the examples as being homework problems involving "Tech Airways", and I am indebted to them since some of their computer solutions are used as examples in the report. As well, the report gives an overview of current research activity in this area in the MIT Flight Transportation Laboratory. A previous report, FTL R68-5 by Professor Amos Levin describes some of the Fleet Routing models and computational methods for solving them. Other reports and theses from the laboratory are referenced where appropriate. I must also recognize the work performed by Dave Benbasset, Norm Clerman, and Thor Paalson in providing computer runs for several of the examples. i
James Love Honor Flight flight card and badge holder
No full textScanned image of James R. Love Utah Honor Flight card and badge holder: Their Memorial, Our Mission
Introduction to Aerial Vehicle Flight Mechanics, Stability and Control
No full textThis article provides an introduction to Section 5.1 on flight mechanics and
dynamics, stability and control, and navigation. It introduces some basic
concepts of flight control, and static and dynamic stability. Some particular
features of vertical or short take-off and landing (V/STOL) aircraft flight
control, not covered elsewhere in this Section, are discussed briefly. The other
articles in this Section are introduced
Flight Capital and its Reversal for Development Financing
No full textcapital flight, flight capital reversal, development finance
Differential Global Positioning System (DGPS) for Flight Testing
No full textIn this AGARDograph, the potential of DGPS as a positioning datum for flight test applications is deeply
discussed. Current technology status and future trends are investigated in order to identify optimal system
architectures for both the on-board and ground station components, and to define optimal strategies for
DGPS data gathering during various flight testing tasks. Limitations of DGPS techniques are deeply
analyzed, and various possible integration schemes with other sensors are considered. Finally, the
architecture of an integrated position reference system suitable for flight test applications is identified.
The purpose of this AGARDograph is to provide comprehensive guidance on assessing the need for and
determining the characteristics of DGPS based position reference systems for flight test activities.
The specific goals are to make available to the NATO flight test community the best practices and advice
for DGPS based systems architecture definition and equipment selection. A variety of flight test
applications are examined and both real-time and post-mission DGPS data requirements are outlined.
Particularly, DGPS accuracy, continuity and integrity issues are considered, and possible improvements
achievable by means of signal augmentation strategies are identified. Possible architectures for integrating
DGPS with other airborne sensors (e.g., INS, Radalt) are presented, with particular emphasis on current and likely future data fusion algorithms. Particular attention is devoted to simulation analysis in support of flight test activities with DGPS. Finally, an outline of current research perspectives in the field of DGPS
technology is given
Development of real-time flight control system for low-cost vehicle
No full textIn recent years, more and more light aircraft enter our daily life, from Agricultural
applications, emergency rescue, flight experiment and training to Barriers to
entry, light aircraft always have their own advantages. Thus, they have become
more and more popular.
However, in the process of GDP research about Flight Control System design
for the Flying Crane, the author read a lot of literature about Flight Control
System design, then noticed that the research in Flight Control System have
apparently neglected to Low-cost vehicles. So it is necessary to do some study
about Flight Control System for this kind of airplane. The study will more
concern the control law design for ultra-light aircraft, the author hopes that with
an ‘intelligence’ Flight Control System design, this kind of aircraft could
sometimes perform flying tasks according to a prearranged flight path and
without a pilot.
As the Piper J-3 cub is very popular and the airframe data can be obtained
more easily, it was selected as an objective aircraft for the control law design.
Finally, a ¼ scale Piper J-3 cub model is selected and the aerodynamics
coefficients are calculated by DATCOM and AVL. Based on the forces and
moments acting on the aircraft, the trim equilibrium was calculated for getting
proper dynamics coefficients for the selected flight conditions. With the aircraft
aerodynamics coefficients, the aircraft dynamics characteristics and flying
qualities are also analyzed. The model studied in this thesis cannot answer
level one flying qualities in the longitudinal axis, which is required by MIL-F-
8785C. The stability augment system is designed to improve the flying qualities
of the longitudinal axis.
The work for autopilot design in this thesis includes five parts. First, the whole
flight profile is designed to automatically control aircraft from takeoff to landing.
Second, takeoff performance and guidance law is studied. Then, landing
performance and trajectory is also investigated. After that, the control law
design is decoupled into longitudinal axis and later-directional axis. Finally,
simulation is executed to check the performance for the auto-controller
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