The backup and standby systems for the secondary flight controls are grouped in two catego-ries:
- High lift devices
If the automated spoiler extension system fails, the speed brake lever must be manually moved at landing or rejected takeoff procedures. There is no backup system available for the spoilers. The spoilers are partly controlled by hydraulic system A and partly by hydraulic system B, which is a safety measure in case one of two systems fail.
If the trailing edge flaps are deployed asymmetrical, which is sensed by the FSEU, hydraulic pressure is automatically removed from the flap drive unit. This prevents damage on the surfaces. If hydraulic system B fails, the trailing edge flaps can be electrically extended and retracted by the alternate flaps switch. The alternate flaps switch controls an electrical motor that performs the extension. The extension can take up to two minutes. The leading edge devices can be controlled by the standby hydraulic system, in an event of a system B failure. The leading edge devices move simultaneously with the trailing edge flaps in case of a failure. The leading edge devices can not be retracted by the standby hydraulic system.