The order in which the different parts of a machine should be aligned is as follows:
1. Alignment of landing gear.
2. Alignment of center section.
3. Alignment of leading edge.
4. Getting both wings the same height.
5. Dihedral angle, if any.
6. Alignment of trailing edge (angle of incidence).
7. Stagger.
8. Droop.
9. Tightening and safetying all wires.
10. Length of struts, positions and fittings, warp in planes.
11. Alignment of ailerons.
12. Alignment of stabilizer.
13. Alignment of elevator flaps.
14. Alignment of rudder.
The tail of the machine should be raised until the fuselage is nearly horizontal before starting the alignment.
1. Alignment of Landing Gear.—When a machine is being assembled, it is easier to align the landing gear before the wings are put on.
Take the weight off the landing gear by supporting the fuselage on sawhorses.
The axle should be parallel with the lateral axis of the machine.
The center of the axle should be directly under the center of the fuselage. This can be secured by either of two methods:
(a) By Measuring Cross Distances.—Loosen and tighten the cross wires until the cross distances are exactly the same. Take all measurements from similar points on the fittings to which the wires are attached.
(b) With Level and Plumb Bob.—Level the fuselage crosswise. Mark the exact center of the fuselage and drop a plumb bob. Mark the exact center of the axle. Adjust the cross wires until the plumb bob is over the center of the axle. Tighten the wires until fairly tight, and safety them.
2. Alignment of the Center Section.—When assembling a machine, the center section should be aligned before the wings are put on.