1975 - Installing and Rigging Wings

 On the Monoplane the Flying Wires attach to the landing gear axle.  On the Biplane the Flying Wires attach to fittings added to the landing gear fittings on the fuselage.  It just requires longer bolts for the added layer of steel.

 The process starts with the lower wings.  Back in the building process each panel was set in place at the correct Dihedral Angle and the holes drilled in the attachment fittings.

 Rope was a convenient way to hold the wings in place temporarily but they stretch too much to be very useful.

Instead, with the plane setting on blocks to level it side-to-side, and fore-and-aft.  Boards were then stood up next to the spars and clamped to the spars to hold the wings with the correct dihedral and incidence (twist).

 The upper wings were then set in place so the struts could be fitted.

 The twist between the upper and lower wings is controlled by the "N" struts.

 With the wings mounted the next task was to position the wings precisely, add the bracing wires and rig them.

Geof Geisz had recently rigged his PJ-295 Senior Aero Sport so he volunteered to use the same method to rig the Fly Baby.

 With the plane level, the first step was to set up a Surveyors Transit to provide a reference for precisely measuring dihedral and incidence angles.

 With each wing panel supported by 2x2 poles clamped to the spars near the tips, Yard Sticks were clamped to the spars next to the strut fittings on the wings and center section.  They are positioned to hang vertically (plum) and extend into the plane of the Transit, so you can see your alignment marks trough the Transit.

It's just a matter of moving each wing spar up and down on it's pole until all the angles are correct.  OK it does require the use of Trigonometry to calculate the distances.  A calculator, with Trig. functions, will give you the Sine of each angle, dihedral or incidence.  Then you measure the distance between 2 yard sticks.  This is the Hypotenuse of the triangle.  Yeah I know, you never thought you'd hear that word after you left high school.  You multiply the Hypotenuse times the Sine to get the change in height from one stick to the next.  You then move each spar up or down on it's pole until all the measurements are correct.
Now if you had clamped the sticks Perpendicular to the spars you could use the Tangent of the angle, but enough higher math.
If you make a diagram of the plane and write down all the measurements then you just keep moving spars until it's all correct.  Today I would probably use my laser level after carefully checking that it is level.

 With the wings held in position by the poles it's a matter of making all the wires and adjusting the turnbuckles to the proper tension.  You only need to support the wings and loosen the landing wires to get the rigging apart.  Everything else can be left safety wired.  When you put the wings back together support the lower wings and pull the landing wires back tight and everything is back in rig.

You could do this by loosening the front flying wires instead.  I think the rigging of the flying wires is more critical and prefer the extra work of supporting the lower wings to loosen the landing wires, besides that is the process for folding the Monoplane wings.

We need some fabric on these wings.