A fully CFD-based methodology for ice particle tracking based on a MonteCarlo statistical approach and a six-degrees-of-freedom particle-tracking module has been developed within the FENSAP-ICE in-flight icing system.
This paper presents a general error model for MCRT algorithms, which is later applied to the calculation of some basic radiative entities. Furthermore, some issues related to the implementation of such models in a software tool are discussed. Finally, the accuracy control methods are applied to the more complex case of the heat flux absorbed in a given radiative face. Although only the relative error is considered through the discussion, similar results can be derived for the absolute error.
This book provides a basic source of technical and legal information to participate intelligently in the search for probable causes and discussion of the legal aspects of aircraft accidents. It should be especially helpful to lawyers and engineers embarking on investigative careers. ...This book could be considered a postgraduate guide for the hardware-oriented aircraft accident investigator, especially the sections on human errors and human factors. This fourth edition includes chapters on the Freedom of Information Act, safety, discovery, spoliation of evidence, Death on the High Seas Act, tort litigation and more.
Axial symmetric flows of a mono-atomic rarefied gas exhausted through the thruster nozzle of an artificial satellite were numerically simulated by the Direct Simulation MonteCarlo method, since the transitional flow regime occurs at altitudes where the enhancement region is several orders of magnitude larger than the nozzle throat diameter of the thruster (high altitude rocket).
For individuals called upon to serve as advisors or technical representatives to official aircraft accident investigation (AAI) teams, an understanding of accident and wreckage reconstruction methodologies and processes is critical to success in this supportive role.
For example, a reconstruction may commence after the roadway on which the accident occurred has been modified. ...The comparisons show that Google Earth images yield reasonably accurate measurements (RMSE 0.569 feet) over the scale of typical accidentreconstruction distances....Google Earth has become a tool often used by accident reconstructionists to create site drawings and obtain dimensional information. In some cases, a reconstructionist will not be able to inspect the site of the crash due to various circumstances.
Available flight recorder data are used to tune the model and reconstruct the accident. Then the model is used for in-depth examination of the accident’s “neighborhood” in autonomous “what-if” simulation experiments under actual and hypothetical conditions. ...Flight accidents with modern aircraft are often a result of complex dynamics of the “pilot (automaton1) - vehicle - operational environment” system. ...An affordable, practically tested technique is proposed to complement current methods of flight accident analysis. A generic situational model of the system behavior and a computer are employed as a virtual test article.
Although there was no human casualty reported, the outcome of this accident could have been much different. In this paper, we investigate the use of distributed simulation and information fusion to better predict the effects, in terms of expectations of casualties (EC), of the different hazards produced by an accidental or instructed loss of such a vehicle.
Basic Science and Art of Aircraft Wreckage Reconstruction is a unique title which addresses important aspects of investigating crashes, who does this kind of work, and how a healthy attitude and open mind are required to properly perform investigations. ...It also discusses what to expect from the on-scene part of the investigation, and the fundamental approaches to common types of wreckage reconstruction. Written by Don Knutson, a veteran of this industry, Basic Science and Art of Aircraft Wreckage Reconstruction is intended for the practitioner, student, or those who are simply curious about how aircraft wreckage is reconstructed. ...Written by Don Knutson, a veteran of this industry, Basic Science and Art of Aircraft Wreckage Reconstruction is intended for the practitioner, student, or those who are simply curious about how aircraft wreckage is reconstructed.
Previous work on this problem has used a rectilinear approach to the calculations involved in the flight parameter reconstruction. The rectilinear approach gives excellent results for relatively straight flight; however, it routinely underestimates the airspeed and the bank angle when the airplane is maneuvering. ...In the present study, the authors present a curvilinear approach to flight parameter reconstruction that addresses this shortcoming. The analysis presented shows that the curvilinear approach is a far superior tool than the rectilinear approach for the reconstruction of maneuvering flight including steep turns and high-speed spirals. ...The analysis presented shows that the curvilinear approach is a far superior tool than the rectilinear approach for the reconstruction of maneuvering flight including steep turns and high-speed spirals.
This paper presents the implementation of flight path reconstruction (FPR) and wind estimation techniques applied to a high performance fighter aircraft. ...The estimation technique applied for data reconstruction is the extended Kalman filtering (EKF). The reconstructed trajectories can be compared with the actual flight trajectories such that, in case of unavailability of data from other sources (e.g., digital flight control computer), the algorithm should be able to reconstruct the trajectories with the minimum set of data available from the CDR. ...Wind estimation along with the trajectory reconstruction can give better accuracy in airspeed as well as flow angles. The algorithm also aims at determining the bias/systematic instrument errors and generating accurate aircraft state trajectories.
Small unmanned aerial systems have gained prominence in their use as tools for mapping the 3-dimensional characteristics of accident sites. Typically, the process of mapping an accident site involves taking a series of overlapping, high resolution photographs of the site, and using photogrammetric software to create a point cloud or mesh of the site. ...These objects represent items commonly found at accident sites. The accident site was then documented with several different unmanned aerial vehicles at differing altitudes, with differing flight patterns, and with different flight control software. ...A mock accident site was created that included a stopped vehicle, a bicycle, and a ladder. These objects represent items commonly found at accident sites.
This paper presents a top-down methodology for causal analysis of fatal aviation accidents. The methodology incorporates a three tiered hierarchical approach to analyze accident causes and factors. ...These include looking at the big picture or “profile” of accident categories, followed by a detailed analysis that “fingerprints” each profile. Finally, an in-depth analysis is performed for each fingerprint which produces a “DNA” sequence breakdown for each accident category. ...Finally, an in-depth analysis is performed for each fingerprint which produces a “DNA” sequence breakdown for each accident category. The paper includes analysis results of National Transportation Safety Board (NTSB) accidents from 1990-1996.
Subsequent to determination of component failure cause, corrective actions and development of field inspection methods are often imperative to preventing accident recurrence. Examples from several analyses of both military and commercial accident hardware are presented. ...High-speed ground impact, fire, secondary damage and the loss of components during an accident greatly hinder component failure analysis efforts and root cause determination. Careful evaluation of unfailed components can often give accident investigators the information needed to fill in gaps and determine the mishap sequence or cause. ...Careful evaluation of unfailed components can often give accident investigators the information needed to fill in gaps and determine the mishap sequence or cause.
Selected meteorological investigations where icing possibly contributed to the accident are also reviewed. A synopsis of the board's history in investigating icing accidents is provided, along with a discussion of various Safety Board recommendations promulgated as a result of icing investigations. ...Icing is one of the primary meteorological factors the National Transportation Safety Board (NTSB) considers when investigating a weather-related aviation accident. Since the late 1960s, the Safety Board has maintained a database that includes aviation accidents in which icing is noted as a cause or factor. ...Since the late 1960s, the Safety Board has maintained a database that includes aviation accidents in which icing is noted as a cause or factor. Utilizing the database, this paper examines the occurrence of aviation accidents associated with icing conditions over a 19-year period (1982-2000).