AIRCRAFT MAINTENANCE MANUAL
DFE-AMM-AR1
Rev. 1 – 07/24/2014
3-29
Trim Tab deflection measurement
The trim tab deflection is measured from the neutral position. When the trim tab profile does
not protrude from the elevator profile with elevator set in neutral position.
1. Attach a protractor with a deflection hand at the trim tab
2. Neutralize the trim tab and the elevator
3. Zero the protractor
4. Set the trim tab in maximum lower or upper position using the trim tab control lever and
read the deflection from the protractor scale.
5. Compare the deflection with that specified in the Control Surfaces Deflection
Requirements. If required - adjust trim tab deflection.
If a protractor is not available, the following procedure may be substituted:
1. Insert a stiff cardboard sheet of paper in the space between the elevator and the trim tab
and hold the cardboard against the elevator.
2. Trace the profile of the neutralized trim tab
3. Move the trim tab to the maximum (both directions) using the trim tab control lever and
trace the profile again
4. Remove the cardboard and measure the deflection from the neutral position using a
protractor
5. Compare the deflection with that specified in the Control Surfaces Deflection
Requirements. If required - adjust trim tab deflections.
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Task proper accomplishment check: None.
3.6.2.2.
Control surfaces deflection setting
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Tools needed: Protractor with a deflection hand, a clip to attach protractor to measured
control surface, Metric Wrenches, Screwdriver.
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Parts needed: 1.6 x 16 mm Cotter Pins
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Type of maintenance: Line
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Level of Certification needed:
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Repairman (LS-M) or Mechanic (A&P) – both with the minimum level of certification to
perform heavy maintenance of SLSA in the U.S.
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FAA approved Part 145 Repair station
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Instructions:
Control surface deflections of a new aircraft are set by the manufacturer. Deflections are
adjusted to values specified in the Control Surfaces Deflection Requirements as specified on
Paragraph 3.6.2.1. of this Section.
A neutral position of the control surfaces and controls is used as a base for adjustment of
deflections.