Fort Hill Group conducted a comprehensive human performance risk assessment on current and future RNAV/RNP operations.
As the Federal Aviation Administration (FAA) continually seeks to improve the efficiency and safety of operations in the National Airspace System, it is increasingly turning to the use of Area Navigation (RNAV) and Required Navigation Performance (RNP). RNAV allows for procedures to be developed using GPS-based waypoints, instead of relying on ground-based, physical navigation aids. This allows airspace designers to develop more efficient approach and departure procedures. RNP extends these benefits by enabling equipped aircraft to fly precise pre-defined flight paths and in some cases, even along curved flightpaths.
The increased use of RNAV and RNP procedures and the capabilities that rely on these procedures represents a significant change to the way controllers manage air traffic. The Federal Aviation Administration’s Human Factors Research and Engineering Division enlisted Fort Hill Group to complete a multi-phase project to identify issues associated with current operations and to assess the changing risk profile as new Next Generation Air Transportation System (NextGen) systems, capabilities, and procedures are introduced.
Current Operations
In an effort to better understand current operations, a human factors safety assessment was conducted to identify the key human factors issues present in RNAV/RNP operations. An Air Traffic Analysis and Classification System (AirTracs) analysis of RNAV/RNP narrative-based safety reports from the Air Traffic Safety Action Program (ATSAP) and the Aviation Safety Reporting System (ASRS) was conducted to identify key causal factors and prominent risk pathways. The analyses found several key causal factors related to RNAV procedure design, controller-pilot communication, air traffic and flight deck automation systems, and track deviations. Specific human performance mitigation strategies for each factor and pathway were developed. Developing a baseline understanding of present risks served to drive mitigation strategies aimed at current day operational issues and to provide NextGen designers with guidance for improving human performance in future RNAV/RNP operations. More information on this study is available in the full report “Human Factors Assessment of RNAV Approach and Departure Procedures” provided below.
NextGen Impact
One of the primary areas of emphasis included in NextGen is the increased utilization of performance-based navigation through RNAV/RNP approach and departure procedures. Fort Hill Group prepared an RNAV/RNP execution factor profile that summarizes the factors impacting RNAV/RNP procedure execution based on a comprehensive review of operational and research reports. Fort Hill Group then developed Human-System Interaction Models (HSIMs) for each planned NextGen change to document the impacts of the changes on actors and systems. A series of workshops were then conducted with subject matter experts from commercial aviation, air traffic control, and human factors to describe the potential positive and negative impacts that each change could have on the factors affecting successful RNAV/RNP procedure execution. The resulting group of impact factors provides a proactive, high-level look at potential changes to the RNAV/RNP human performance risk profile associated with executing planned NextGen changes. This will allow system and procedure designers to minimize operational risks and maximize human performance as NextGen changes are implemented.
