Effect of Angle of Attack Displays on Approach Stability

摘要

Although piloting an aircraft throughout history has remained essentially the same, the information that the pilot must interpret and the interface through which they accomplish control has changed dramatically. Examples such as autopilots, flight directors, and glass cockpits to name a few have necessitated that pilots interface with their aircraft in a ways not originally foreseen. Despite all of these technology advancements, many of which are designed to help with aircraft control, a loss of control due to stall/spin encounters continues to be a primary killer in both general and commercial aviation alike. In the presented research, the utilization of an Angle of Attack (AOA) indicator was assessed to determine if the stability of the approach was impacted with varying levels of exposure to an angle of attack display and education on the concepts of angle of attack and the mechanisms by which the chosen display illustrates the angle of attack during various phases of flight. While the primary objective of an AOA display is to provide a current understanding of the current AOA and its proximity to the critical AOA to prevent unintentional aerodynamic stalls, there are potentially other benefits and additional insights that can be provided to the pilot. The primary objective of this study was to conduct a comparative analysis for pilots to conduct a stabilized approach both with and without AOA displays. Four study design groups participated in the study from three different universities and with three different aircraft flown. Participants were recruited from both the local general aviation population and the flight schools of the three participating universities. In order to measure the stability of the approach, the Flight Path Angle (FPA) was measured at 1 second intervals along the approach utilizing a stand-alone Attitude Heading and Reference System (AHRS). The FPAs between the 1 second intervals was determined and the absolute value of the difference between a given second and its subsequent second value was calculated. The sum of the variations in the FPAs for the last 30 seconds was calculated and then compared across all participant groups. Here we report the findings of how the utilization of an AOA display affected approach stability and how the landscape of AOA accessibility in the GA market has developed in recent years.