Diamond DA 42 NG, Maintenance Manual

Page: 891 / 2339

AIRCRAFT
DA 42 NG AMM Flight Controls
Doc # 7.02.15
Rev. 4
27-38-00
Page 5
15 Mar 2018
C. Trim Tab Actuator Assembly
The trim tab is a one-piece GFRP molding. The tab has two integral levers. Two cranked actuating
levers attach to the integral levers. The left cranked actuating lever connects to the long flexible
cable. The right actuating lever connects to a friction damper.
The friction damper has a clamp-block with a hole for a rod. The rod connects to the right actuating
lever on the trim tab. You can adjust the friction of the rod in the clamp block.
3. Operation
When you move the top of the trim handwheel forward these things happen:
)
The small gear wheel moves the top of the gear segment forward.
)
The gear segment pulls the inner core of the flexible cable forward.
)
The inner core of the flexible cable pulls the left cranked actuating lever forward.
)
The left cranked actuating lever pulls the trim tab lever forward to move the trim tab upwards.
)
The up movement of the trim tab uses aerodynamic forces to push the elevator down in flight giving
nose-down trim.
When you move the top of the trim handwheel aft, the gear segment moves aft, the cable moves aft
and the trim tab moves down. This pushes the elevator up during flight to give nose up trim.
In each case the pilot can see the trim position from the white mark on the gear segment.
4. Emergency Operation
In the event of a failure of the mechanical trim control system between the handwheel and the trim
actuator lever, the friction damper will prevent the trim tab from fluttering.