Impacts of Dual Head-Up Display Use on Workload in the Civil Aviation Flight Deck: Implications for Crew Coordination.

In a two-person flight crew, the ability of each crewmember to maintain a shared mental model during flight is foundational to flight safety. The addition of a head-up display (HUD) for the pilot flying (PF) represents a departure from traditional flight deck design where each pilot is able to view the same primary flight display. With a single HUD, the PF is able to use a display that is not available to the PM. As such, operating an aircraft with a single HUD may alter the shared mental model compared to operating an aircraft with dual HUDs. In the case of single HUD use during approach and landing, the PM does not see the primary flight information that the HUD superimposes onto earth-based reference points. The PM also is unable to maintain visual contact with out-the-window visual information while simultaneously monitoring flight information. As such, the PM may experience different workload levels when monitoring without a HUD compared to monitoring with a HUD. The present study attempts to uncover the contribution of dual HUD use to the optimization of crew workload by measuring pilots’ workload during a series of simulated, low-visibility approach and landing scenarios in a flight simulator. After each scenario, pilot workload was measured using the NASA Task Load Index (NASA-TLX). Crew workload was evaluated as a function of dual HUD vs. single HUD use and runway visual range (RVR). The findings regarding crew workload, crew coordination, and HUD use are discussed.