General Aviation Pilot Situation Assessment and Decision-Making During Flights in Deteriorating Visibility Conditions
Ahlstrom, U., Racine, N. Caddigan, E., Schulz, K. & Hallman, K. (2019). General Aviation Pilot Situation Assessment and Decision-Making During Flights in Deteriorating Visibility Conditions. (DOT/FAA/TC-19/32). Atlantic City International Airport, NJ: FAA William Hughes Technical Center.
One of the most dangerous things a General Aviation (GA) pilot who is flying Visual Flight Rules (VFR) flights can do is fly into Instrument Meteorological Conditions (IMC) (bad weather areas where they can no longer fly solely by means of visual references), yet it happens too often, despite access to weather information. This paper describes two human-in-the-loop cockpit simulations to assess whether enhancing the salience of the weather symbols or using a decision support tool (referred to as active reminders) impact pilot decision-making and behavior during flights in deteriorating weather conditions. Ninety-three private GA pilots participated in Simulation 1 and 95 participated in Simulation 2. Pilots were between the ages of 18-83. In Simulation 1, participants were randomly allocated to one of two enhanced weather presentations. In Simulation 1, our results show no difference between pilot use of frequency-tuned salience analysis and enhanced METAR symbols (i.e., triangles and circles) with detection rates of 52% and 62%. The detection rate for METAR triangles in the study is higher than previous research; however, the effect of increasing the METAR symbol salience on change-detection performance was only about 12%, which is not enough to guarantee an unfailing detection by pilots. In Simulation 2, participants were randomly allocated to one of two groups, one of which provided a blue line as an active reminder of forecasted visibility conditions and the distance from the aircraft to hazardous precipitation. In Simulation 2, the results shows a clear benefit of the active reminder display with a credibly higher weather situation awareness for the experimental group compared to the control group (no active reminder/blue line). We also found that, on average, pilots underestimate the “out-the-window” visibility for a range of simulated visibilities. This reveals a gap in pilot situational assessments and undermines a high weather situational awareness during flights in deteriorating visibility. The failure to assess current visibility conditions increases the odds of VFR-into-IMC flights.