Application of winglets and/or wing tip extensions with active load control on the Boeing 747

The application of wing tip modifications and active control technology to the Boeing 747 airplane for the purpose of improving fuel efficiency is considered. Wing tip extensions, wing tip winglets, and the use of the outboard ailerons for active wing load alleviation are described. Modest performance improvements are indicated. A costs versus benefits approach is taken to decide which, if any, of the concepts warrant further development and flight test leading to possible incorporation into production airplanes

Rule-based air combat simulation

An improved version of the Adaptive Maneuvering Logic (AML) program for air-combat maneuvering is discussed. The modifications and improvements incorporated into the AML program are documented

Quiet Supersonic Flights 2018 (QSF18) Test: Galveston, Texas Risk Reduction for Future Community Testing with a Low-Boom Flight Demonstration Vehicle

The Quiet Supersonic Flights 2018 (QSF18) Program was designed to develop tools and methods for demonstration of overland supersonic flight with an acceptable sonic boom, and collect a large dataset of responses from a representative sample of the population. Phase 1 provided the basis for a low amplitude sonic boom testing in six different climate regions that will enable international regulatory agencies to draft a noise-based standard for certifying civilian supersonic overland flight. Phase 2 successfully executed a large scale test in Galveston, Texas, developed well documented data sets, calculated dose response relationships, yielded lessons, and identified future risk reduction activities

Flight control systems development and flight test experience with the HiMAT research vehicles

Two highly maneuverable aircraft technology (HiMAT) remotely piloted vehicles were flown a total of 26 flights. These subscale vehicles were of advanced aerodynamic configuration with advanced technology concepts such as composite and metallic structures, digital integrated propulsion control, and ground (primary) and airborne (backup) relaxed static stability, digital fly-by-wire control systems. Extensive systems development, checkout, and flight qualification were required to conduct the flight test program. The design maneuver goal was to achieve a sustained 8-g turn at Mach 0.9 at an altitude of 25,000 feet. This goal was achieved, along with the acquisition of high-quality flight data at subsonic and supersonic Mach numbers. Control systems were modified in a variety of ways using the flight-determined aerodynamic characteristics. The HiMAT program was successfully completed with approximately 11 hours of total flight time

Design study of general aviation collision avoidance system

The selection and design of a time/frequency collision avoidance system for use in general aviation aircraft is discussed. The modifications to airline transport collision avoidance equipment which were made to produce the simpler general aviation system are described. The threat determination capabilities and operating principles of the general aviation system are illustrated

Modeling of an Autonomous Underwater Vehicle

Autonomous Underwater Vehicles (AUV) have multiple applications for military, commercial and research purposes. The main advantage of this technology is its independence. Since these vehicles operate autonomously, the need for a dedicated support vessel and human supervision is dismissed. However, the autonomous nature of AUVs also presents a complex challenge for the guidance, navigation and control system(s). The design of motion controllers for AUVs is model-based i.e. a dynamic model is used for the design of the control system. The dynamic model can also be used for simulation and performance analysis. In this context, the purpose of this thesis is to provide a dynamic model for a double-body research AUV being developed at CEiiA. This model is to be subsequently used for the design of the control system. Since the purpose is the design of the control system and, in the scope of providing multiple design approaches, the appropriate lateral and longitudinal subsystems are devised. These subsystems are subsequently validated by comparing simulation results for the subsystems with simulation results for the complete model. The AUV is modeled using Fossen’s dynamic model. The model is divided into kinematics and kinetics. Kinematics addresses the geometrical aspects of motion. For this purpose, both Euler angles and quaternions are used. Kinetics focuses on the relationship between motion and force. This model identifies four distinct forces that act on the underwater vehicle: rigid-body forces; hydrostatic forces; hydrosynamic damping (or drag) and added-mass. The estimation of model parameters is performed using analytical and computational methods. A detailed 3D CAD model, developed by CEiiA, proved helpful for estimating mass and inertia parameters as well as hydrostatic forces. Hydrodynamic damping estimation was performed by adapting CFD analysis, also developed by CEiiA, to satisfy model parameters. Added mass parameters were estimated using proven analytical methods. Due to limitations inherent to current modeling methods, simplifications were unavoidable. These, when analyzed considering the requirements of typical control systems, did not pose an impediment to the use of the dynamic model for this purpose. Regarding the dynamics of this AUV, the hydrodynamic analysis suggests that this AUV is unstable in the presence of angles of attack and side-slip. However the AUV’s motors should be capable of controlling such instabilities.Os veículos subaquáticos autónomos (Autonomous Underwater Vehicles – AUV’s) têm múltiplas aplicações militares, comerciais e para investigação científica. A grande vantagem destes veículos advém da sua independência, sendo que operam sem a necessidade de supervisão humana. No entanto esta capacidade implica que os sistemas de navegação, guia e controlo sejam completamente responsáveis pelo governo do veículo. O sistema de controlo destes veículos é tipicamente projetado tendo como base um modelo dinâmico do mesmo. Este modelo pode ser também usado para simulação e análise de desempenho. O propósito deste trabalho é desenvolver um modelo dinâmico para um AUV de investigação de duplo-corpo, a ser desenvolvido no CEiiA. Dado que o objetivo principal do modelo é projetar controladores e, de modo a fornecer várias abordagens para o efeito, os respetivos modelos (subsistemas) lateral e longitudinal são deduzidos. Estes modelos são posteriormente validados através da comparação de resultados de simulação para os subsistemas com os resultados de simulação para o modelo completo. A modelação deste veículo é efetuada usando o modelo dinâmico de Fossen. Este modelo pode ser dividido em cinemática e cinética. Cinemática aborda os aspetos geométricos do movimento. As equações de cinemática são fornecidas tanto para ângulos de Euler como para quaterniões. As equações de cinética centram-se na relação entre movimento e força. O modelo de Fossen identifica quatro forças distintas que influenciam a dinâmica dos veículos subaquáticos: forças de corpo rígido; forças hidrostáticas; amortecimento (atrito) hidrodinâmico e added mass. Estas forças são modeladas através de métodos analíticos e computacionais. O modelo CAD do veículo, desenvolvido pelo CEiiA, foi usado para estimar os parâmetros de massa e inércia, bem como forças hidrostáticas. O amortecimento hidrodinâmico foi estimado através da adaptação de análises CFD, também efetuadas pelo CEiiA, para satisfazer os parâmetros do modelo. Os parâmetros added mass foram estimados usando métodos analíticos comprovados. Devido a limitações inerentes aos métodos de modelação atuais, simplificações foram inevitáveis. As mesmas, quando analisadas tendo em conta os requisitos de sistemas de controlo típicos não provaram ser impeditivas da aplicação deste modelo para o desenvolvimento dos mesmos. No que diz respeito à dinâmica deste AUV, a análise hidrodinâmica sugere que este AUV é instável quando na presença de ângulos de ataque e derrapagem. No entanto os motores do AUV deverão ser capazes de corrigir tais instabilidades

Piloted simulation of an algorithm for onboard control of time-optimal intercept

A piloted simulation of algorithms for onboard computation of trajectories for time-optimal intercept of a moving target by an F-8 aircraft is described. The algorithms, use singular perturbation techniques, generate commands in the cockpit. By centering the horizontal and vertical needles, the pilot flies an approximation to a time-optimal intercept trajectory. Example simulations are shown and statistical data on the pilot's performance when presented with different display and computation modes are described

Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

The development, testing, production activities, and associated costs that were required to produce five-and-one-half advanced-composite stabilizer shipsets for Boeing 737 aircraft are defined and discussed