11. One of three hydraulic power units had overheated, and the pilots switched to a backup. 12. One of three hydraulic power units had overheated, and the pilots switched to a backup circuit. 13. One of three hydraulic power units overheated, and the pilots switched to a backup controller to cool it before shutting down each unit as planned. 14. The bellcranks, attached to a hydraulic power control unit, help move the elevators at the rear of the plane. |