THE HUMAN FACTORS OF FMS USAGE IN THE TERMINAL AREA Katharine K. Lee, Beverly D. Sanford, and Rhonda A. Slattery Abstract The development of advanced automation for arrival aircraft into the terminal area is being investigated for both the air traffic control (ATC) and airborne environments. For the automation to be effective and provide the best advisory information, aircraft trajectories must be accurately estimated. One way to enhance the aircraft's adherence to the trajectories assumed by advanced ATC automation is to supply trajectory information to the pilots. Such information is currently provided by ATC to pilots through voice communication. Providing the advisories to the pilots via their Flight Management Systems (FMS) could help improve the timeliness of the advisories, especially in a time-critical terminal area environment. To successfully implement the FMS for use in the terminal area, human factors issues such as pilot workload and the usability and understandability of the information presented via the FMS must be addressed. This study examines the human factors aspects of FMS usage strategies by commercial airline crews flying a Boeing 747-400 full-motion simulator in a terminal area flight segment. Results indicate that FMS-guided flight in the terminal area creates significantly higher amounts of individual crewmembers' head-down time, and increased levels of self-reported workload compared to conventional navigational means.