Predicting Pilot Task Demand Load During Final Approach

Abstract

This research aims at developing a method to assess the safety of airport approaches from the perspective of airline pilots. The main hypothesis is that safety is inversely proportional to the task demand load (TDL) experienced by the pilots conducting it. The TDL is the mental workload imposed by the system to be controlled, and is not to be mistaken for the mental workload experienced by the operator, referred to as mental load. This article presents the results of preliminary research that focused on how some of the environmental factors that determine the approach, such as the type of aircraft and the meteorological conditions, affect the TDL. A paper pilot model, consisting of a scanning model, mental model, and control model, was used to quantify how hard an average pilot has to work to conduct the specified approach. Offline computer simulations with this model revealed some clear trends in pilot scanning rate, task error, and control activity, as a function of the environmental factors, which will eventually allow for a prediction and quantification of the TDL. Depending on the approach performance requirements on the one hand, and the pilot scanning capacity on the other, increasing turbulence intensity showed a change in trend for all TDL-related parameters at a particular turbulence intensity. Results from a pilot-in-the-loop evaluation, conducted in a fixed-base flight simulator, supported the main trends of the offline simulation trials. They also indicated that through adopting different scanning strategies, pilots can leverage their workload; more research is necessary to clarify this result, however.