Dissertations and Theses 11-2013 Comparison of Three Angle of Attack (AOA) Indicators: A Usability Study Camilo Jimenez Embry-Riddle Aeronautical University - Daytona Beach Follow this and additional works at: https://commons.erau.edu/edt Part of the Aviation Commons, and the Psychology Commons Scholarly Commons Citation Jimenez, Camilo, "Comparison of Three Angle of Attack (AOA) Indicators: A Usability Study" (2013). Dissertations and Theses. 85. https://commons.erau.edu/edt/85 This Thesis - Open Access is brought to you for free and open access by Scholarly Commons. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. COMPARISON OF THREE ANGLE OF ATTACK (AOA) INDICATORS: A USABILITY STUDY By Camilo Jimenez A Thesis Submitted to the College of Arts and Sciences in Partial Fulfillment of the Requirements for the Degree of Master in Science in Human Factors and Systems i Embry-Riddle Aeronautical University Daytona Beach, Florida November 2013 ii ABSTRACT Researcher: Camilo Jimenez Title: COMPARISON OF THREE ANGLE OF ATTACK (AOA) INDICATORS: A USABILITY STUDY Institution: Embry-Riddle Aeronautical University Degree: Master in Science in Human Factors and Systems Year: 2013 Angle of Attack (AOA) is an important aeronautical concept used to understand the performance status of an aircraft during different flight stages. The Federal Aviation Administration (FAA) has indicated the importance of developing and encouraging the use of affordable AOA based systems to increase inflight safety. Embry-Riddle Aeronautical University’s flight department decided to install AOA indicators in its fleet of Cessna 172S, to increase safety and to help student pilots better understand this important concept. This paper presents a review of AOA, visual display design principles, and usability. This experimental study examined three different AOA indicators provided by the flight department. The goal was to conduct a usability study in order to understand which of these indicators was better suited for student training. Instructor pilots were used as participants in a series of flights, in which they were asked to perform different maneuvers in which using AOA indicators was thought to help increasing stall awareness and performance. At the end of each flight participants were asked to complete a series of surveys (including an adaptation of the system usability scale) and to provide comments in order to understand their preferences related to AOA indicators. The analysis of the data shows significant differences between the indicators. Discussion of the results and recommendations for future studies are also covered. iv TABLE OF CONTENTS Review Committee Signature Page .............................................................................................................. iii Abstract ........................................................................................................................................................ iv List of Tables .............................................................................................................................................. vii List of Figures ............................................................................................................................................ viii Introduction ................................................................................................................................................... 1 Significance of the Study .......................................................................................................................... 6 Purpose Statement ..................................................................................................................................... 7 Hypotheses ................................................................................................................................................ 7 Limitations and Assumptions ................................................................................................................... 8 Definition of Terms ................................................................................................................................... 8 List of Acronyms ...................................................................................................................................... 9 Review of the Relevant Literature .............................................................................................................. 10 Angle of attack ........................................................................................................................................ 10 Usability .................................................................................................................................................. 12 Methods ...................................................................................................................................................... 20 Research Approach ................................................................................................................................. 20 Sample .................................................................................................................................................... 20 Apparatus and Materials ......................................................................................................................... 21 Design and Procedures ............................................................................................................................ 22 Sources of the Data ................................................................................................................................. 25 Data Collection Device ........................................................................................................................... 25 Instrument reliability and validity ....................................................................................................... 25 Treatment of the Data ............................................................................................................................. 26 Results ......................................................................................................................................................... 27 Discussion, Conclusion, and Limitations .................................................................................................... 38 Discussion ............................................................................................................................................... 38 Conclusion .............................................................................................................................................. 45 Limitations .............................................................................................................................................. 48 References ................................................................................................................................................... 51 v Appendices A Approximate AOA Indications for Each Flight Maneuver ...................................................... 56 B Informed Consent Form ........................................................................................................... 58 C Pre-Flight Questionnaire .......................................................................................................... 61 D Post-Flight Questionnaire......................................................................................................... 67 vi LIST OF TABLES Table 1 Mean and Standard Deviation for SUS............................................................................ 28 Table 2 Mean and Standard Deviation for Visual Representation ............................................... 28 Table 3 Pairwise Comparisons for Visual Representation ........................................................... 29 Table 4 Mean and Standard Deviation for Enhanced Performance .............................................. 29 Table 5 Pairwise Comparisons for Enhanced Performance .......................................................... 30 Table 6 Mean and Standard Deviation for Enhanced Stall Awareness ........................................ 30 Table 7 Pairwise Comparisons for Enhanced Stall Awareness .................................................... 31 Table 8 Mean and Standard Deviation for Crosschecked Indicator During Maneuvers .............. 31 Table 9 Mean and Standard Deviation for Indicator would Enhance Students’ Performance ..... 32 Table 10 Ranks for Crosschecking the Indicator helped in Flying a More Stable Approach on Final (Normal Approach and Landing)......................................................................................... 32 Table 11 Ranks for Crosschecking the Indicator helped in Flying a More Stable Approach on Final (Short Field Approach and Landing) ................................................................................... 33 Table 12 Ranks for Crosschecking Indicator Enhanced Landing Performance (Normal Approach and Landing) ................................................................................................................................. 33 Table 13 Ranks for Crosschecking Indicator Enhanced Landing Performance (Short Field Approach and Landing)