Comparative Risks of Visual versus Sensor-based Inspection

This paper presents an overview of a study conducted in 1997 to evaluate the comparative risks of conducting pre-takeoff inspection based on visual observation, point detection sensor systems and remote detection sensor systems. Regulations, airline procedures, sensor systems, the effects of fluid failure on aerodynamic performance and the likelihood of an accident were reviewed. Risk analysis techniques were used to analyse available data. Observations of fluid failure progression were studied; detailed surveys of pilots' experience were conducted to establish a reference base. It was concluded that point detection sensor systems would reduce the risk of accident at takeoff compared to visual inspection. Insufficient data was available for conclusions to be drawn concerning use of remote area sensors.

Progress has been made recently that would allow an upgrade of the original study. Theoretical studies and wind tunnel tests, together with test experience with remote sensors at the deicing pad have expanded the information base, although the issue of sensor threshold for pre-takeoff inspection remains outstanding.