Brian Kish

The general aviation industry suffers from high rates of fatalities due to loss of control. This papers provides a method to implement a simplified vehicle operations (SVO) scheme using an autopilot system to create a pilot-on-the-loop controller. With this scheme, the pilot controls turn rate and climb rate instead of bank angle and pitch attitude. A Raspberry Pi is used with a software package to interface with the autopilot system. Any type of controller or joystick can be used to translate pilot inputs into readable autopilot commands. The readable commands are generated in ARINC 429 format. The control logic takes in current autopilot flight state data from the aircraft, combines it with pilot joystick inputs, and generates heading and vertical speed commands for transmission to the autopilot system. Ground testing was performed before flight testing to ensure that each major component of the software was functioning properly. Novice pilots were used to evaluate the effectiveness of this hybrid fly-by-wire concept. This research demonstrates the development of one SVO scheme that can help create safer practices in the general aviation industry.

Loss of control at low altitude in the traffic pattern is one of the main causes of fatal accidents in general aviation. A large number of loss-of-control accidents can be attributed to the pilot loosing awareness of the energy state of the aircraft. An intuitive and accessible display for energy state and specific excess power can potentially remedy these types of accidents. As general aviation aircraft are not equipped to measure a large number of dynamic parameters, such a predictive energy display must be based on an algorithm running on a reduced set of parameters readily available from the current generation of light aircraft avionics. This paper discusses the challenges associated with designing a predictive projection-based or screen-based display for light aircraft and presents prototype solutions. Furthermore, the paper presents a number of energy state prediction algorithms and reports the flight test results producing the underlying aircraft performance database. The work presented has great potential of resulting in low-cost, easy-to-use, energy state prediction, warning and guidance displays based on available aircraft parameters.

The Joint Strategic Target Attack Radar System (JSTARS) has a long history of sending its development test aircraft into real-world, operational events. Typically, weapon systems are not tasked for real-world events until their test programs are complete. Intelligence, surveillance, and reconnaissance platforms like JSTARS are sometimes allowed to participate from afar in real-world events because they do not interfere with operations, yet they can provide needed targeting data. This paper presents the results of demonstrations conducted on the JSTARS test aircraft in 2010 and 2011. The prototype systems had not been fully tested nor approved as funded programs. The demonstrations proved JSTARS capabilities apply to more than just military operations. JSTARS capabilities can also be used for disaster relief, homeland security, and law enforcement. This paper also identifies the typical challenges of a demonstration and provides the steps needed for success.

Students at the United States Air Force Test Pilot School, successfully completed a limited evaluation of an 802.11b air-to-air WiFi data link between two C-12C test aircraft. The test team determined the maximum range capability for 1 megabit per second (Mbps) and 11 Mbps transmissions over the WiFi data link when transmitting at 1 or 5 Watts of amplifier power, corresponding to 0.32 and 1.58 Watts of effective isotropic radiated power, respectively. Diagnostic and performance statistic software on laptops were used to gather the data rate and performance statistics in flight, while post flight analysis was conducted to retrieve the data link range statistics. The flight test results closely matched the predicted maximum ranges found using an RF link prediction model, accounting for cabling losses, amplification, antenna gain, free space losses, amplifier receive gain, and the published SecNetll^reg receiver sensitivity. Increased reception range could have been achieved using lower loss RF cabling and placing the amplifier closer the antenna. Of the available configurations tested (ad hoc, infrastructure and bridge), ad hoc was found the most reliable. The test team also demonstrated the capability of transmitting and receiving text files, still images, pre-recorded video, and streaming, live webcam video between the two test aircraft.

This paper describes the design and testing of a high-speed, real-time kinematic, precise differential GPS positioning system for use in airborne applications such as automated aerial-refueling and close formation flying. Many of the current ambiguity resolution techniques use the residuals from the least squares position estimation to determine the true ambiguity set, this paper presents a novel approach to the ambiguity resolution problem, called the minimum indicator. Instead of assuming the ambiguity set with the lowest residuals is the true set, other special characteristics of the residuals are examined. The result was the first-ever successful six-degree of freedom, in-flight demonstration of close formation flight, culminating in over 11 hours of close formation flying with a mean radial spherical error of 3.3 centimeters. Other areas addressed include: the difference between "pre-fit" and "post-fit" residuals in the conditional probability calculation, and the impact of a simplified dynamics model on system performance.