Most general aviation aircraft manufactured today come with "glass cockpits." Instead of being equipped with mechanical gauges and indicators, they are equipped with computer screens. The screens integrate and display all sorts of useful flight information. The information displayed may include satellite weather, synthetic vision, infrared vision, terrain awareness information, traffic
information, and moving maps. Glass cockpits are supposed to help improve the pilot’s "situational awareness."
Not surprisingly, glass cockpits have been marketed as a safety advantage. From the website of one manufacturer, Cirrus Aircraft:
We included new safety features to reduce your work load and anxiety by giving you more time to think and improving flight environment manageability. Ultimately, with [our glass cockpit] you get a smoother, more precise flying experience while all the time knowing you are flying smarter, flying safer.
The NTSB agrees that glass cockpits have the potential to improve safety. But to the surprise of many, the NTSB has now found that, to date, they have not. To the contrary, aircraft equipped with glass cockpits have a higher than fatal accident rate than comparable aircraft equipped with the old-fashioned, hard-to-decipher mechanical gauges.
Study analyses of aircraft accident and activity data showed a decrease in total accident rates but an increase in fatal accident rates for the selected group of glass cockpit aircraft when compared to similar conventionally equipped aircraft during the study period. Overall, study analyses did not show a significant improvement in safety for the glass cockpit study group.
How can this be? More information, presented to the pilot in an easy-to-understand fashion, is supposed to be a good thing. The NTSB’s findings have left many scratching their heads.
I’ve written before that the poor safety record may simply be the result of "Risk Homeostasis" at work. Risk Homeostasis theory suggests that, when given the opportunity, pilots will use a safety feature to enhance the aircraft’s utility rather than enjoy the increased level of safety the feature could provide. In other words, pilots use the the glass cockpits to fly into conditions that they would otherwise avoid. And, instead of painstakingly preparing for the flight before they depart, they prepare "on the fly" (so to speak), relying on the glass cockpit to tell them what they need to know.
A feature – whether it is a glass cockpit or an airframe parachute – can serve as a safety feature or one that enhances an aircraft’s utility. It can’t do both.
Related Content From the NTSB:
- NTSB Overview Report (pdf)
- Findings & Recommendations (pdf)
- Closing Comments (pdf)
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