Flaps and Slats
The flaps and slats are high lift devices that increase wing lift and decrease stall speed
during takeoff, low speed maneuvering and landing. LE (Leading Edge) devices consist of
four flaps and eight slats: two flaps inboard and four slats outboard of each engine. Slats
extend to form a sealed or slotted leading edge depending on the TE (Trailing Edge) flap
setting. The TE devices consist of double slotted flaps inboard and outboard of each
engine. TE flap positions 1–15 provide increased lift; positions 15–40 provide increased lift
and drag. Flaps 15, 30 and 40 are normal landing flap positions. Flaps 15 is normally
limited to airports where approach climb performance is a factor.
Flap and Slat Sequencing
LE devices and TE flaps are normally extended and retracted by hydraulic power from
system B. When the FLAP lever is in the UP detent, all flaps and LE devices are
commanded to the retracted or up position. Moving the FLAP lever aft allows selection of
flap detent positions 1, 2, 5, 10, 15, 25, 30 or 40. The LE devices deployment is sequenced
as a function of TE flaps deployment.
When the FLAP lever is moved from the UP position to the 1, 2, or 5 position, the TE flaps
extend to the commanded position and the LE:
When the FLAP lever is moved beyond the 5 position the TE flaps extend to the
commanded position and the LE:
The LE devices sequence is reversed upon retraction.
- Flaps extend to the full extended position and
- slats extend to the extend position.
- Flaps remain at the full extended position and
- slats extend to the full extended position.
