XtremeAIR XA41, Maintenance Manual

Page: 196 / 284

Maintenance Manual XA41/XA42
AMM-XA42-0040-001 C.00
Page 10 Page date:
Chapter 51 25.09.2018
51-60-00 CONTROL SURFACE BALANCING
51-60-01 Weighing and Calculation of the Control Surface Moments
To weigh a control surface or to calculate its moment, it is necessary to remove the control
surface from the aircraft. You must weigh and calculate the control surface moments after
each repair or painting procedure.
Weigh the control surface in the disassembled condition. The balance masses are installed in
the structure and it is not possible to disassemble them. When you remove the balance
masses, the control surface becomes unserviceable.
To calculate the control surface moment, use the form below:
1 Record the mass at the specified arm and multiply it with the correct arm (distance
between the weighing point and the hinge line).
2 Make sure that the control surface moment is in the given tolerances. Refer to
Appendix 6 for the form of the control surface mass and moment.
To calculate the mass at the specified arm and the control surface moments:
1 Remove the control surface, refer to chapter 27.
2 Install the hinge pin.
3 Put the hinge pin onto two mandrels, one on each side of the control surface. The
mandrels must not touch the control surface. For the Flettner tab, use a string to
hold the hinge pin of the tab.
4 Calculate the balance mass at the specified arm and record the mass in the form FO
P-24. See Appendix 6.
5 Calculate the control surface moment as follows: Multiply the arm, the mass at that
arm and the gravitation constant (9,81m/s²).
6 Make sure that the values are in the permitted tolerances.
7 Install the control surface, refer to chapter 27.
Control
surface
Mass
[kg]
Arm*
[m]
Balance mass at
specified arm
[kg]
Aileron, LH 6,4 – 9,4kg 0,286m 0,8 – 1,4kg
Aileron, RH 6,4 – 9,4kg 0,286m 0,8 – 1,4kg
Elevator w/o
Flettner
10,0 – 13,0kg 0,56m 0,3 – 1,8kg
Rudder 5,2 – 6,2kg 0,87m 0,7 – 1,5kg
Flettner Tab 0,35 – 0,55kg 0,145m 0,05 – 0,15kg
*Distance between the weighing point and the hinge line.
If the weighing point was repaired: Measure the length of the arm and use this value to
calculate the control surface moment.