Date of Award


Document Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Graduate Studies

Committee Chair

Kelly J. Neville, Ph.D.

First Committee Member

Albert J. Boquet, Ph.D.

Second Committee Member

Alan J. Stolzer, Ph.D.


Analysis of accident data by the Federal Aviation Administration, the National Transportation Safety Board, and other sources show that loss of control is the leading cause of aircraft accidents. Further evaluation of the data indicates that the majority of loss of control accidents are caused by the aircraft stalling. In response to these data, the Federal Aviation Administration and the General Aviation Joint Steering Committee emphasize the importance of stall and angle-of-attack awareness during flight. The high-profile crash of Air France Flight 447, in which pilots failed to recover from a self-induced stall, reinforced concerns over the need for improved stall and angle-of-attack awareness and reinvigorated interest in the debate over the effectiveness of angle-of-attack information displays. Further support for aerodynamic information in the form of an angle-of-attack indicator comes from core cognitive engineering principles. These principles argue for the provision of information about system functioning and dynamics as a means to ensure a human is always in position to recover a system when technology is unable. The purpose of this research was to empirically evaluate the importance of providing pilots with feedback about fundamental aircraft aerodynamics, especially during non-standard situations and unexpected disturbances. An experiment was conducted using a flight simulator to test the effects of in-cockpit angle-of-attack indication on aircraft control following an airspeed indicator malfunction on final approach. Participants flew a final approach with a target airspeed range of 60 to 65 knots. Once participants slowed the aircraft for final approach, the airspeed indicator needle would be stuck at an indication of 70 knots. One group of participants flew the final approach with an angle-of-attack indicator while the other group lacked such an instrument. Examination of aircraft performance data along the final approach showed that, when confronted with a frozen airspeed indicator, pilots flying with an angle-of-attack indicator were producing less airspeed and glideslope deviation than pilots who were flying without an angle-of-attack indicator. Furthermore, in the absence of airspeed information, pilots with an angle-of-attack indicator were less prone to slow the aircraft to an airspeed at which the aural stall-warning activated. Overall, the results of this experiment provide support for making aerodynamic information available to the pilot, thus contributing empirical results to the aviation-safety debate over the effectiveness of angle-of-attack information displays.