In a span of only a few years, the cockpits of new light aircraft have undergone a transition from conventional analog flight instruments to digital-based electronic displays commonly referred to as “glass cockpits.” These new displays integrate aircraft control, autopilot, communication, navigation, and aircraft system monitoring functions, applying technology previously available only in transport-category aircraft. The enhanced function and information capabilities of glass cockpits represent a significant change and potential improvement in the way general aviation pilots monitor information needed to control their aircraft. The National Transportation Safety Board (NTSB) initiated this study to determine if the transition to glass cockpits in light aircraft has improved the safety record of those aircraft.
Three different approaches were used in this study. First, a retrospective statistical analysis of manufacturer records, aircraft investigation information, and activity survey data was conducted to compare the accident experience of recently manufactured light single-engine airplanes equipped and not equipped with glass cockpit displays. Second, an evaluation of glass cockpit training requirements and resources was conducted to characterize the training and to identify areas for potential safety improvement. Finally, accident cases were reviewed to identify emerging safety issues associated with the introduction of glass cockpit displays into this class of aircraft.
The statistical analysis found that for 2002–2008, light single-engine aircraft equipped with glass cockpit displays experienced lower total accident rates—but higher fatal accident rates—than the same type of aircraft equipped with conventional analog instrumentation. Accidents involving glass cockpit aircraft were more likely to be associated with personal/business flights, longer flights, instrument flight plans, and single-pilot operations, while accidents involving conventional analog cockpit aircraft were more likely to be associated with instructional flights, shorter flights, and two-pilot operations. Accident pilots flying glass cockpit equipped aircraft were found to have higher levels of pilot certification and more total flight experience than those flying conventional aircraft.
The evaluation of light aircraft glass cockpit training requirements found that the Federal Aviation Administration (FAA) has been updating training handbooks and test standards to incorporate generic information about electronic flight instrument displays. However, current airman knowledge written tests (such as private pilot, instrument rating, commercial pilot, and flight instructor certificates) do not assess pilots’ knowledge of the functionality of glass cockpit displays. In addition, the FAA has no specific training requirements for pilots operating glass cockpit-equipped light aircraft. The lack of equipment-specific training requirements from the FAA results in a wide range of initial and recurrent training experiences among pilots of glass cockpit aircraft. With the exception of training provided by airframe manufacturers with the purchase of a new aircraft, pilots must currently seek out and obtain equipment-specific glass cockpit training on their own.
The review of accidents involving light aircraft equipped with glass cockpits found that pilots’ experiences and training in conventional cockpits do not prepare them to safely operate the complex and varied glass cockpit systems being installed in light aircraft today. Further, the lack of information provided to pilots about glass cockpit systems may lead them to misunderstand or misinterpret system failures. As a result, there is a need for new training procedures and tools to ensure that pilots are adequately prepared to safely operate aircraft equipped with glass cockpit avionics.
The results of this study suggest that the introduction of glass cockpits has not resulted in a measurable improvement in safety when compared to similar aircraft with conventional instruments. The analyses conducted during the study identified safety issues in two areas:
- The need for pilots to have sufficient equipment-specific knowledge and proficiency to safely operate aircraft equipped with glass cockpit avionics.
- The need to capture maintenance and operational information in order to assess the reliability of glass cockpit avionics in light aircraft.
As a result of this safety study, the NTSB made six recommendations to the FAA: five address training requirements and one addresses reporting requirements.