Diamond DA 42 NG, Maintenance Manual

Page: 915 / 2339

AIRCRAFT
DA 42 NG AMM Flight Controls
Doc # 7.02.15
Rev. 4
27-50-00
Page 7
15 Mar 2018
3. Operation
If you operate the flap selector switch these things happen:
)
The switch energizes the related logic circuit.
)
The logic circuit switches on the related transistors to supply power/ground to the flap motor.
)
The flap motor turns the reduction gear and spindle. This moves the actuator pushrod towards the
new set position.
)
The push rod turns the idler lever around its axis.
)
The idler lever moves the flap operating pushrods in the fuselage and the wings.
)
The push-rods move the flap bellcranks in the left and right wings.
)
The short pushrods move the flaps.
When the flap position reaches the position set by the flap selector:
)
The cam on the flap actuator operates the related flap position and indication micro switches.
)
The logic circuit switches off the related transistors to de-energize the flap motor.
)
The flap position indicator shows the new flap position.
4. Fail-Safe Operation
The flap control system has these fail-safe properties:
)
If the LDG position micro switch fails closed the flap actuator pushrod will continue to travel for
about 5 mm (0.2 in) until it reaches an internal stop. This prevents damage to the flaps. The FLAP
circuit breaker opens and breaks the flap operating circuit.
)
If the UP position micro switch fails closed, the actuator pushrod contacts the end of the actuator
body after about 5 mm (0.2 in) of movement. This prevents damage to the flaps. The FLAP circuit
breaker opens and breaks the flap operating circuit.