Research Projects

Angle of Attack Equipment

Project Duration

08-13-2013 to 03-31-2015

Project Summary

Analysis of Angle of Attack Devices for General Aviation Video

The General Aviation Joint Steering Committee (GA-JSC) is a joint Federal Aviation Administration (FAA) and aviation industry group established with the goal of improving the safety in general aviation (GA). The GAJSC’s technical arm, the Safety Analysis Team (SAT), identifies safety issues and develops mitigation solutions and strategies for the GAJSC to implement in GA. In April 2011, the GAJSC chartered the SAT to conduct a review of fatal GA accidents from 2001 through 2010. The SAT reviewed 2,472 fatal general aviation accidents based on Commercial Aviation Safety Team/International Civil Aviation Organization (CAST/ICAO) Common Taxonomy Team (CICTT) categories and identified Loss of Control – Inflight (LOC-I) accidents as the most prevalent accident type with 1,259 fatal. Industry and Government have agreed to propose a data-driven approach to identifying high priority safety initiatives for GA and jointly agree to work toward the mitigation of accident causes. The LOC Working Group (LOC-WG) was formed by the FAA and GA industry to review GA accidents related to LOC and to recommend safety enhancements. Some of the safety enhancements recommended by the LOC-WG are pertaining to the usage of Angle of Attack (AOA) systems in GA aircraft.


The Angle of Attack is the angle formed by the chord of the airfoil and the flight path of an aircraft. The increase in AOA increases lift up to a point, called critical angle of attack (CAA), where the AOA exceeds the limit and results in a loss of lift. The aircraft wing is said to be in a stall when it reaches the CAA. The use of AOA system in an aircraft keeps the pilot informed of the AOA related to the aircraft performance; thus, allowing the pilot to reduce the risk of an inadvertent stall resulting in a loss of control. It is important to note that although this technology is readily available, AOA systems are not required equipment and are not widely used in the GA community. There has been evaluative work concerning the awareness of angle of attack and potential stall conditions by groups such as the American Bonanza Society, Aircraft Owners and Pilots Association (AOPA), Boeing, and others when utilizing Angle of Attack Displays for angle of attack awareness. Pilots that have adopted AOA displays verbalize the benefit that is to be gained in the understanding of the complete picture that is presented when AOA displays are utilized as a crosschecking tool with airspeed indicators and attitude indicators.


However, the method of interpretation and analysis especially as a crosscheck mechanism for instrumentation displays may vary substantially depending on the aircraft avionics suite and AOA display that is installed in the aircraft being operated. In collaboration with pilot advocacy and industry groups such as AOPA, Experimental Aviation Association (EAA), and General Aviation Manufacturers Association (GAMA), this research will study the possible benefits and incentives for the installation and usage of AOA systems in the GA environment specifically towards applications in stabilized approaches.


The ultimate aim of this research is to provide pilots and instructors with information that could provide additional assistance to interpret the flight path & aircraft attitude relationship.  The current analysis of AOA displays is anecdotal in nature and there needs to be a rigorous study accomplished which solidifies the touted benefits by various industry groups. The expected outcomes of the project are:

FAA Technical Point of Contact

Michael Vu - Federal Aviation Administration (

Technical Point of Contact

Brian Dillman - Purdue University (



Lead Organization: Purdue University

Other Participating Organizations