FLAPS AND SLATS

The five slats and two flaps on each wing are electrically controlled and hydraulically actuated via inputs form the flap lever. Signals from the flap lever are transmitted to the two flap slat control computers (SFCC). The slats are operated by the green and blue hydraulic systems and the flaps by the green and yellow systems. If one hydraulic system fails its associated surfaces will operate at half speed. If one SFCC fails, all the slats and flaps will operate at half speed.

There four hydraulically operated wing tip brakes (WTB)to stop the slats or flaps moving in case of asymmetry, overspeed, uncommanded movement and symmetrical runaway. The wing tip brakes cannot be rest in flight, and furthermore, their circuit breakers (red collared) must never be pulled in flight. If the slats are locked out by the wingtip brakes, it is still permissible to operate the flaps and vice versa.

There is also a flap disconnect system, that operates if there is excessive differential movement detected, between the inner and outer flap on each wing; this might occur if one of the surfaces attachments fail and the system is therefore designed to stop further damage. If the slats are locked out by the wingtip brakes, it is still permissible to operate the flaps and vice versa.

There is an alpha lock system that stops the flaps from being retracted at excessive angles of attack or low airspeed. The inhibition is removed when the angle of attack is decreased or the speed is increased.

Flaps 1 + F 

When flaps are selected to position 1 or CONFIG 1 on the ground, they will extend to position 1+F, which is Slats 18° and Flaps 10°. After takeoff, if the airspeed goes above 210kts, with the aircraft still in CONFIG 1, the Flaps will automatically retract to 0° and the Slats will remain extended until they are retracted, by physically moving the flap lever to position 0.

During flight, when the flap lever is selected to CONFIG 1, only the Slatswill extend to 18°. The first Flap movement will be at CONFIG 2, where the flaps will extend to 15°. After flap retraction, CONFIG 1 + F is not available until the speed is below 100kts, unless flaps 2 or more has been selected and the flaps are retracted again i.e. during a go-around.

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