Boeing engineers design airplanes to both prevent failures and to provide protection in the unlikely event that there is a failure. Boeing designs include multiple levels of redundancy – backups – so that no single failure can cause an accident.
Critical systems are separated by function and space ensuring that the loss of one system will not cause the loss of its backup. A robust and ready network of standby and protective systems is designed and built into every Boeing airplane.
Boeing also designs safety into its airplanes with crews in mind. Boeing flight decks are designed so that pilots are always in command and can override automatic controls.
Advanced instrumentation and airplane monitoring tools, and sensory cues such as audible alarms, lighted indicators and moving throttles, control wheels and rudder pedals, are designed to help the crew know continuously how the airplane is responding.