AIRCRAFT MAINTENANCE MANUAL
DFE-AMM-AR1
Rev. 1 – 07/24/2014
3-28
Elevator deflection measurement
The starting position to measure the elevator deflections is the neutral positions of the
control stick and elevator. The neutral position of the control stick is set by the aircraft
manufacturer, by means of a jig. The distances between the control stick and instrument panel,
and between the control stick and fuselage side can be used to set the neutral position. When
the elevator is in the neutral position, the chord of the Horizontal tail unit will be parallel to upper
edge of the fuselage side (lower frame of the cockpit).
1. Attach a protractor with a deflection hand at the elevator trailing edge
2. Set the elevator to the neutral position
3. Zero the protractor
4. Fully pull or push the control stick to deflect the elevator and read the deflection
5. Compare the measured deflections with those specified in the Control Surfaces
Deflection Requirements. If required - adjust elevator deflection.
If a protractor is not available, the following procedure may be substituted:
1. Support the airplane under the tail skid and firewall and set the airplane in a horizontal
position (a level set on the canopy lower frame can be used to set the airplane in
horizontal position)
2. Stand a suitable staff close to the elevator trailing edge and mark the neutral position of
the elevator.
3. Move the control stick and fully deflect the elevator. Mark the positions of the elevator
while fully deflected
4. Measure the distances between marks on the staff
5. Compare the measured deflections with those specified in the Control Surfaces
Deflection Requirements. If required - adjust elevator deflection.
Rudder deflection measurement
The rudder deflections are set by the aircraft manufacturer. A measuring instrument is used
by the aircraft manufacturer to measure the rudder deflections. The instrument is put on the
vertical tail unit and a rudder deflection may be read directly.
The rudder deflection may be measured however, when the set the rudder is set to the
neutral position. Stand a suitable staff at the ruder trailing edge and mark lower edge of the
rudder. Fully deflect the rudder and measure using a ruler between the mark on the staff and
the lower edge of the rudder. Compare the measured distance with that specified in the Control
Surfaces Deflection Requirements.
