Figure 16-37.--Slat drive system.
Placing of the flap control handle to either the
spring-operated brake engages, preventing relative
motion between the inboard and outboard sections.
TAKEOFF or LAND position mechanically closes
switches to provide electrical current to the slat
SLAT ANGLE GEARBOXES.--Four slat angle
selector valve. The selector valve ports hydraulic
gearboxes are provided in the slat system for changing
pressure to the extend side of the high-speed hydraulic
direction of the slat torque tube linkage from the center
motor. This action drives the center gearbox and
gearbox to the wing actuators.
extends the slats.
DIRECT LIFT CONTROL (DLC)
Two ball screw actuators drive each outboard slat,
and one drives each inboard slat of each wing. Each
Direct lift control controls the spoilers and
actuator connects to its downstream actuator by torque
horizontal stabilizers to increase aircraft vertical
tubes and gearboxes. The slats move as one unit. Limit
descent rate during landings. This may be done without
switches in the center drive gearbox de-energize the
c h a n g i n g e n g i n e p o w e r. A c t u a t i n g t h e D L C
slat selector valve, blocking flow to the drive motor
engage-chaff dispense push-button switch on the
when the slats fully extend (27.5 degrees) or retract.
control stick grip modifies the pitch and roll computer
Placing the flap control handle to the UP position
inputs. This modification causes the eight spoiler
energizes the opposite solenoid of the selector valve
actuators to position their spoilers 3 degrees up from
and reverses slat motor direction, retracting the slats.
the 0-degree position. The pitch computer also
SLAT WING FOLD GEARBOX.--A wing fold
generates the DLC servo actuator command drive at
gearbox disconnects slat drive linkage at the wing fold
the time of DLC engagement. This command drive,
joint when the wings fold. The gearbox consists of two
which is applied to the DLC servo actuator, drives the
identical halves interconnected by a spring-loaded
stabilizers to the 6-degree trailing edge down position
disconnect coupling when the wings are spread. As
from the 0-degree position. In DLC, the pitch computer
the disconnect coupling halves move away from
and the roll computer permit additional spoiler and
s t a b i l i z e r c o n t r o l t h r o u g h t h e D L C - m a n e u ve r,
each other during the wing folding operation, a
16-42
