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Preflight Preparations
Before you leave the workshop for the flying field, take these important steps.
Looking from the front of the model, check that the bottom of the wing and tail
surfaces are flat - not twisted. Sight down the center line of the fuselage as shown
in the drawing. Right and left wing should look alike; you shouldn't see the top of
one wing and the bottom of the other. The fin should point straight ahead, and the
stabilizer should be flat. (This does not mean that the stabilizer and the wing sit on
the fuselage at the same angle. The wing will be tilted upward more than the tail).
A model can be made to fly with twisted surfaces, but it's confusing to adjust and if
the warps change from day to day, you can't detect it. The drawing shows how a
surface can be straightened by twisting it in the desired direction while holding it
under a heat lamp or other electric heater. Work with it until it is as flat as possible.
If your wing has struts, loosen them before bending and re-cement them afterward.
The correct "Balance Point" for your ship is shown on the plans. Mark this point on
the bottom surface of each wing. When supporting your plane on your finger tips at
these points, the fuselage should hang level. See the drawing. Add weight to the
nose or tail until it DOES hang level. Don't be afraid to add the necessary weight.
CORRECT BALANCE IS MORE IMPORTANT THAN LIGHT WEIGHT.
Modeling clay makes handy balancing weight - it can be pressed permanently in
any corner. Wire solder or BB shot can be used by cementing in place.
If one blade of your propeller always swings to the bottom, a tiny smear of clay on the other tip will improve the prop's balance
and reduce vibration.
Power-Off Tests
A rubber-powered model is adjusted
in two steps. First, the tail surfaces are
adjusted to produce a good glide.
Then the propeller assembly is
adjusted to give a smooth, powered
flight. Wait for a calm day.
Begin by gliding the model from your hand into a patch of tall grass. Grasp the ship by the fuselage near the balance point, and
aim the nose at a spot on the ground about twenty feet in front of you. Launch the ship forward about the way you would a
paper dart airplane, nose down.
Your goal is a steady glide to the ground, moving at a CONSTANT SPEED, and travelling straight ahead or turning gently. You
will find the trick is to launch the model at its natural speed and glide angle. If the glide is poor, it can mean that the ship needs
adjustment or that you need more launching practice. So try several launches before deciding on adjustment changes. When
your ship acts the same way on each launch, you can be pretty sure that you are seeing its true characteristics, and not just a
poor launch.
