A flight engineer focuses on monitoring mechanical systems and the engine during flight. Prior to flight they perform engine checks and will check all systems to ensure that they are working properly. They also assist with flight plan preparation and make sure the craft has enough fuel for the planned flight. During flight they monitor fuel levels, monitor the engine and monitor all mechanical and electrical systems to make sure everything is working properly. They also document all checks and any changes made, and they answer any questions the captain has. In some cases the flight engineer is also the first officer.
