Date of Award

Summer 2011

Access Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

Dahai Liu, Ph.D.

First Committee Member

Christina Frederick-Recascino, Ph.D.

Second Committee Member

John A. Wise, Ph.D.


Unoccupied Aircraft Systems (UAS) are in the midst of aviation`s next generation. UAS are being utilized at an increasing rate by military and security operations and are becoming widely popular in usage from search and rescue and weather research to homeland security and border patrol. The Federal Aviation Administration (FAA) is currently working to define acceptable UAS performance standards and procedures for routine access for their use in the National Airspace System (NAS). This study examined the effects of system reliability and time pressure on unoccupied aircraft systems operator performance and mental workload. Twenty-four undergraduate and graduate students, male and female, from Embry-Riddle Aeronautical University participated in this study on a voluntary basis. The primary tasks were image processing time and target acquisition accuracy; three secondary tasks were concerned with responding to events encountered in typical UAS operations. Mental workload, using the NASA-Task Load Index (TLX) form, and trust levels of Multi-Modal Immersive Intelligent Interface for Remote Operation (MIIIRO) system were also studied and analyzed. System reliability was found to produce a significant effect for image processing time, while time pressure produced a significant effect for target acquisition accuracy and mental workload. A significant effect was found for the interaction between system reliability and time pressure for pop-up threats re-routing processing time. The results were examined and recommendations for future research are discussed.