Diamond DA 42 NG, Maintenance Manual

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AIRCRAFT
DA 42 NG AMM Flight Controls
Doc # 7.02.15
Rev. 4
27-50-00
Page 5
15 Mar 2018
C. Flap Electrical Control
Figure 4 shows the flap electrical control system. The main bus supplies the power for the flaps.
A circuit breaker protects the system. See Chapter 92 for the Wiring Diagrams.
The flap electrical control system uses solid state electronics. It has an electronic control unit and
a switchboard. The electronic control unit is mounted on the instrument panel. Then switchboard
attaches to the flap actuator.
The electronic control unit has a 3-position selector switch and a flap position indicator. The
selector switch can be set to:
)
UP (fully up) 0° ± 1°
)
APP (approach) 20° ± 2°
)
LDG (landing) 42° ± 1°
The flap position indicator has three light emitting diodes. The top diode lights when the flaps are
in the UP position. The middle diode lights when the flaps rare in the APP position. The bottom
diode lights when the flaps are in the LDG position.
The switch board attaches to the body of the flap actuator. The switch board has five micro
switches. It also has solid state logic board.
The logic circuits monitor the outputs from the selector switch and the micro switches on the switch
board. They control four power transistors. Two of the power transistors can connect the power
supply to the flap motor. The other two can connect the motor to ground.
Two screws attach each micro switch to the switchboard. You can adjust the position of the switch
board with three worm drive clamps. The micro switches have these functions:
)
Micro switch 1 - UP position.
)
Micro switch 2 - UP indication and APP position moving down.
)
Micro switch 3 - APP indication.
)
Micro switch 4 - LDG position.
)
Micro switch 5 - LDG indication APP position moving up.
Cable harnesses with multi pin connectors connect the components.