In the wake of the Lion Air and Ethiopian Airlines crashes of Boeing 737 Max planes, people are thinking about how much of their air travel is handled by software and automated systems—as opposed to the friendly pilots sitting in the cockpit.

Older commercial airliners, such as the Beechcraft 1900, which are still in service mostly as small commuter aircraft, often do not have any autopilot installed. By contrast, modern commercial airliners have automated systems that can augment or even replace pilots’ performance, managing engine power, controlling and navigating the aircraft, and in some cases, even completing landings.

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