Effect of Data Communications on Pilot Situation Awareness, Decision Making, and Workload

Abstract

Over the next decade, the demand for air transportation and other airspace services is expected to grow significantly. To address this, the Federal Aviation Administration (FAA) is developing the Next Generation Air Transportation System (NextGen), which is a series of transformations designed to increase the capacity, safety, and security of air traffic operations. One major enabling technology being investigated is data communications (data comm), which is an electronic text-based message-transferring system between aircraft and ground stations. The literature on data communications outlines both potential benefits and costs. On the benefits side, subject matter experts and researchers have suggested that the switch to text-based communications will lead to reduced distractions and workload (Hoogeboom, Joosse, Hodgetts, Straussberger, & Schaefer, 2004; Navarro & Sikorski, 1999). In addition, data communication is thought to be more accurate and concise (Kerns, 1991; Prinzo, 2001). On the costs side, pilots have reported their belief that loss of information gained through the party line leads to a loss of situation awareness (Prinzo & Campbell, 2008; Hodgetts et al., 2005). Pilots seem particularly concerned with the loss of party line information related to weather, traffic, and holding situations (Pritchett & Hansman, 1997; Pritchett, Midkiff, & Hansman, 1995) and with the loss of information during the busier phases of flight near the airport (Pritchett et al., 1995). However, Boehm-Davis, Gee, Baker, and Medina-Mora (2010) found that while some information presented over the party line is important to pilots’ situation awareness, it may be possible to mitigate the loss of the party line by providing supplemental information with data comm. The purpose of this study was to evaluate the impact of data communications on pilot situation awareness, decision making, and workload. This study built upon a previous study by Boehm-Davis, et al. (2010), which examined party line loss and mitigation strategies. In this study, a two-pilot crew was asked to fly two 40-minute flight scenarios using a low fidelity desktop computer-based flight simulator. The independent variable was communication modality, which was a within-subjects variable. Participants flew one scenario with all communication with air traffic control handled via auditory communication channels. In this condition, they were able to overhear party line communications between other aircraft and ATC. Participants flew the other scenario with all communication with ATC handled via data communications. In this condition, the pilots received clearances from ATC via data comm, and also received data comm messages regarding flight events. Situation awareness and workload were assessed during the flight using the Situation Present Assessment Method (SPAM) (Durso & Dattel, 2004). In this method, participants are interrupted from their primary task with queries about their situation. Accuracy and response time are used as measures of their situation awareness and workload. Subjective workload was measured at the end of each flight, using the NASA-Task Load Index (NASA-TLX) (Hart & Staveland, 1988). Pilot decision making was also assessed. Throughout the experiments, a former airline pilot observed the participants and assessed their awareness, planning, decision making, and actions in response to specific flight events. No significant differences were found for the SPAM workload or situation awareness times or in the number of correct responses to the SPAM situation awareness questions. Likewise, there was no significant difference in subjective workload between conditions, as measured with the NASA-TLX. When presented with specific flight events, participants showed slightly greater awareness, discussion, and action in the data comm condition than in the voice condition. However, this difference was not significant. In addition, pilots were less likely to seek information from ATC in the data comm condition, which could potentially reduce workload for controllers. Although this study did not yield many statistically significant results, the findings imply that there may not be a loss of situation awareness, degradation of decision making, or increase in workload when using data comm instead of voice communications, especially with a well-designed data comm interface, sufficient training, and clear procedures.