A flap connection strut connects the adjacent inboard and outboard flap ends. Attached to the flap connection strut are flap disconnect sensors. The sensors send signals to stop the flap movement, if the strut movement is more than the specified limits
The proximity switches of the FLAP disconnect detection system send signals to the Landing Gear Control Interface Units ( LGCIU ). The LGCIU send this signals to SFCC1 and SFCC2. If too much flap movement is found, then the conditions listed below occur: - the flap PCU is switched off - a warning is sent to the flight crew.
Flap Attachment Failure Detection Sensors The SFCCs monitor the flap-attachment failure detection sensors to find connection failure. If the SFCCs receive a flap disconnect signal: - the valve block solenoids on the PCU are de-energized - the POBs lock the two hydraulic motors - the SFCCs give a class 1 level 2 caution and the ECAM display unit shows a failure message. System reset is only possible on the ground. The ECAM display unit shows a failure message if: - the SFCC gets different data from the two sensors on the same wing or - one sensor gives incorrect data.
Flap Interconnecting Strut The flap interconnecting strut has these functions: - it lets the inner and the outer flaps move independently by a specified limit - it gives a different load path for the flap drive system if there is an attachment failure - it sends data to the SFCC when the independent movement of the inner and outer flaps is more than the specified limit - it absorbs energy if a flap drive disconnect occurs. The flap interconnecting strut has: - a housing - two flap-attachment failure detection sensors - an actuating rod - a target - a ball piece-a sleeve.
The housing contains the actuating rod, the sleeve and the ball piece. The target is at the end of the actuating rod. The two sensors on the housing align with the targets on the actuating rod, with the flaps in their normal postion. The actuating rod has a total travel of 18 mm (0.7086 in.) in each direction from the center position. The limit of independent movement between the flaps is 14.5 mm (0.5708 in.). The sensors send a target-far signal to the LGCIU if the target moves more than 15 mm (0.5905 in.) from the center position.
System Jam Detection The SFCC will find a system jam if the system speed is below 2% nominal for more than 4 seconds. When the SFCC's find a system jam: - the valve block solenoids on the PCU are de-energized - the POBs are applied and stop their related hydraulic motors - the SFCCs give a class 1 level 2 caution and the ECAM display unit shows a failure message. If the SFCC's receive a new correct CSU signal, the SFCC's go back to their normal operation. If there is low hydraulic pressure, the SFCC's stop system jam monitoring.