We study the collision avoidance between two aircraft flying in the same vertical plane: a host aircraft on a glide path and an intruder aircraft on a horizontal trajectory below that of the host aircraft and heading in the opposite direction. Assuming that the intruder aircraft is uncooperative, the host aircraft executes an optimal abort landing maneuver: it applies maximum thrust setting and maximum angle of attack lifting the flight path over the original path, thereby increasing the timewise minimum distance between the two aircraft and, in this way, avoiding the potential collision. In the presence of weak constraints on the aircraft and/or the environment, the angle of attack must be brought to the maximum value and kept there until the maximin point is reached. On the other hand, in the presence of strong constraints on the aircraft and the environment, desaturation of the angle of attack might have to take place before the maximin point is reached. This thesis includes four parts. In the first part, after an introduction and review of the available literature, we reformulate and solve the one-subarc Chebyshev maximin problem as a two-subarc Bolza-Pontryagin problem in which the avoidance and the recovery maneuvers are treated simultaneously. In the second part, we develop a guidance scheme (gamma guidance) capable of approximating the optimal trajectory in real time. In the third part, we present the algorithms employed to solve the one-subarc and two-subarc problems. In the fourth part, we decompose the two-subarc Bolza-Pontryagin problem into two one-subarc problems: the avoidance problem and the recovery problem, to be solved in sequence; remarkably, for problems where the ratio of total maneuver time to avoidance time is sufficiently large (≥5), this simplified procedure predicts accurately the location of the maximin point as well as the maximin distance.

Four measurement options for Orion autonomous optical lunar navigation are analyzed using linear covariance analysis methods. The measurements include a feature tracking camera measurement, star landmark elevation measurement, star horizon elevation measurement, and star occultation measurement. Based on trade studies performed, the star landmark measurement is superior to the star horizon measurement closer to the lunar surface, while the horizon sensor has better performance above an altitude of several thousand kilometers. The feature tracking camera performs comparably to the star landmark measurement. The star occultation camera is the worst performer throughout all trajectories due to the inability to include measurements continuously. However, its ability to take occultation measurements on the sunlit or eclipsed side of the Moon makes it a valuable aid to the crater-based measurements, which can only be taken over a sunlit surface.

Four measurement options for Orion autonomous optical lunar navigation are analyzed using linear covariance analysis methods. The measurements include a feature tracking camera measurement, star landmark elevation measurement, star horizon elevation measurement, and star occultation measurement. Based on trade studies performed, the star landmark measurement is superior to the star horizon measurement closer to the lunar surface, while the horizon sensor has better performance above an altitude of several thousand kilometers. The feature tracking camera performs comparably to the star landmark measurement. The star occultation camera is the worst performer throughout all trajectories due to the inability to include measurements continuously. However, its ability to take occultation measurements on the sunlit or eclipsed side of the Moon makes it a valuable aid to the crater-based measurements, which can only be taken over a sunlit surface.

A high fidelity trajectory propagator for use in targeting and reference trajectory generation is developed for aerospace applications in low Earth and translunar orbits. The dominant perturbing effects necessary to accurately model vehicle motion in these dynamic environments are incorporated into a numerical predictor-corrector scheme to converge on a realistic trajectory incorporating multi-body gravitation, high order gravity, atmospheric drag, and solar radiation pressure. The predictor-corrector algorithm is shown to reliably produce accurate required velocities to meet constraints on the final position for the dominant perturbation effects modeled. Low fidelity conic state propagation techniques such as Lambert's method and multiconic pseudostate theory are developed to provide a suitable initial guess. Feasibility of the method is demonstrated through sensitivity analysis to the initial guess for a bounding set of cases.

Linear covariance analysis is a powerful tool for spacecraft rendezvous analysis and design. This methodology is capable of generating results which compare well with the results of a Monte Carlo simulation while requiring dramatically less computation time. The introduction of multiple events triggered on state conditions causes discrepancies between the linear covariance analysis and theoretical results. This thesis introduces techniques for applying multiple event triggers to linear covariance analysis. The proposed technique is validated by comparison with a Monte Carlo simulation involving 1000 runs. The trajectories generated by the Monte Carlo simulation are compared to the 3Q trajectory dispersions from linear covariance analysis. Further, the Monte Carlo simulation navigation filter and the linear covariance analysis on-board covariance matrices are examined in detail. A time of arrival dispersion analysis is performed for each event trigger and an event near the end of the trajectory.

During the entry phase of a human lunar mission, an entry guidance algorithm is used to safely steer the return vehicle through the atmosphere to a target landing site. The PredGuid entry guidance algorithm is enhanced to improve performance and satisfy a set of assumed mission requirements. The enhanced algorithm utilizes an improved numeric predictor-corrector (NPC) to perform precision targeting and generate steering commands for direct, loft, and skip entry scenarios. Analyses show that an energy management approach for short-range targets was is required. The Enhanced PredGuid algorithm is tested and compared to previous versions of the PredGuid algorithm using high-fidelity six-degree-of-freedom simulation of vehicle dynamics. The enhanced algorithm features robust precision landing capability for target ranges from 2000 km to 10000 km and adequate deceleration management for target ranges greater than 2000 km.

Kinematic equations were developed to describe the dynamic motions of the aircraft piston engine components in terms of time dependent position, velocity, and acceleration relationships. Using the Aeronca E-113 engine as a case study, the brake mean effective pressure (BMEP) rating was used to model the cylinder gas pressure profile. The moments of inertia of the dynamic components including connecting rod, crankshaft, and propeller were measured using a pendulum swing method. Representative values were obtained for inertial and gas pressure forces acting on crankshaft journals, connecting rods, and cylinder walls. The resulting model can help in the design of crankshafts and other dynamically loaded parts to resist failure due to fatigue.

Digitization of physical parameters for the display and recording by computers is the essential aspect of any airborne data acquisition system. The objective of this thesis was to develop a data acquisition system for General Aviation research and certification flight testing based on a low-cost Commercial Off-The- Shelf (COTS) hardware, in particular, a common glass cockpit system for experimental aircraft. A kneeboard computer was used to monitor data communications between the various devices of the Grand Rapids Technology (GRT) Electronic Flight Information System (EFIS). The monitored data was then displayed for use in-flight, and recorded aboard the aircraft for post-flight data reduction. The developed system and software was tested in simulation on virtual and actual hardware, on an Extra 300 in ground testing, and in flight. An in flight air-data calibration and several common stability and control certification test points were flown to evaluate and demonstrate the usefulness of the system. Special consideration was paid to work flow prior to, during, and after the flight with the overall goal of reducing the time required for data reduction. The output of this research work includes software for decoding data files logged on one common low-cost EFIS, software for monitoring, displaying, and recording EFIS data on a kneeboard computer in-flight, and tools for managing and viewing data files after the flight. From this research work, it is concluded that commercially available EFIS systems do in fact provide a core data set which is useful in flight research and flight test certification programs. The 15 Hz sampling rate of the GRT system was more than sufficient for all the test points evaluated as a part of this research. The cost of the tested hardware was less than $10,000 at current pricing (2009). The resultant system is compact, adds little weight to a test aircraft, has few interfaces to aircraft systems, and allows for future growth and the incorporation of new sensor types and interfaces. The addition of a flight test air-data boom with angle of attack and sideslip vanes and control position and force sensors would create a very complete data acquisition package without the expense of purpose designed hardware.

A study was undertaken to assess the effectiveness of the CF188 main landing gear upgrade on reducing Planing Link Mechanism failures. Two main landing gear configurations were studied: the prototype configuration and, for comparison purposes, the current configuration referred to as the baseline. Under this study, the flight test data that was analyzed came from key measurements recorded during maintenance rigging procedures, pilot ground handling quality ratings, and from over 80 landings at different descent rates and aircraft attitudes. Landings consisted of touch and go, full stop, cable overrun and cable engagement. The aircraft that was used through the flight test program had both its main landing gears instrumented. While the prototype configuration had minimal impact on the ground handling characteristics, it demonstrated promising results during maintenance activities as well as loads distribution during landings. The prototype was easier to rig which will allow the use of tighter limits further standardizing the complex maintenance procedure. From both a static and dynamic point of view, the hold down force was significantly increased. Within the scope of this study, it was found that the CF188 main landing gear upgrade will reduce Planing Link Mechanism failures.

The purpose of this thesis was to investigate if it would be possible to integrate a developmental Radar Warning Receiver named “The Puffer” onto a Tier 2 Unmanned Aerial Vehicle, and incorporate the Multifunctional Information Display System/Low Volume Terminal into the UAV‟s ground control station. This integration of systems would become a low cost platform that could provide an Electronic Surveillance and geolocation capability of known mobile threat systems. The results of this investigation showed that the Puffer could be integrated on to the Tier 2 UAV with minor modifications. To control and fully integrate the downlink messages from multiple UAVs plus add the capability to send the information out to other units over Link16 would require a major hardware effort with a sizable software integration effort. While this would be an extensive project, the results could be done at a significant cost saving compared to the manned platforms in use today.