This document summarizes a student project to test how rudder angle affects the flight of a model glider. The students built four iterations of their glider, testing rudders at 180 and 60 degrees. Their data showed the 180-degree rudder allowed the glider to fly farther and longer, on average, than the 60-degree rudder. They conclude a flatter rudder creates better balance and less air resistance for their glider design.

1. Team members: Rebecca Blaisdell (Cabot, VT),
Emily Campbell (Montpelier, VT)

2. Abstract
What is aeronautics? Put simply, it is the
study and design of air- and space-craft. In the
aeronautics strand of Governor’s Institute, we
spent a week building and launching a delta wing
aircraft. A delta wing is a plane with a pair of wings
that fold out into a triangle shape.

3. Purpose
The purpose of our project is to determine what
impact a tail rudder will have on the movement and
distance of our craft. We will be testing a variety of
aluminum rudders. These rudders will be attached to a
light-weight craft that will then be shot out of an air
cannon.

4. Hypothesis
The 60 degree rudder will cause the glider to fly
the farthest.
-Our reasoning for this was that the drag on the
60 degree rudder would compensate for the
heavier front end of the plane, ultimately giving it
more lift and making it fly higher and farther.

5. Procedure
Day one: Rainbow Split 1.0
The fuselage of our glider is made of PVC, and our rudders attach via two
paperclips. Our wings are made from parts of an old umbrella (specifically the
moving joints and the fabric). They are kept out by a set of rubber bands in a small
wooden housing.
This craft turned out to be incredibly heavy, and didn’t fly well at all. The
tension on the rubber bands was too low to keep the wings fully open in flight, and
the wood components broke easily.

6. Procedure
Day two: Rainbow Split 1.1
We replaced the fuselage
with wood, and redid the
rubber band system. The
tension is now mush
tighter and any problems
with the bands are easier
to fix. However, our
system for attaching
rudders (not shown
here) is still paperclips,
which are not very
effective.

7. Procedure
Day three: Rainbow Split 1.2
In this model, we added a
better rudder attachment.
It is a spring-loaded
system that locks the
rudder into place. It
proved to be much more
effective than the paper
clips. We also spaced out
the rubber bands so that
the tension was greater.

8. Procedure
Day four: Rainbow Split 1.4
We created the design for the rudders we
would use in testing and cut some of
them out. We also added a metal support
to the body and stitched it on. In
addition to that, we added a bumper to
the front of the glider to serve as
protection against otherwise catastrophic
nose dives. Rainbow Split 1.4 ended up
being our final model, with only a few
tweaks here and there. It was the lightest,
most well-balanced of our models.

9. Procedure
Day five: Testing day!
We pretty much just ran tests
on day five. We did tweak a
few things, such as the rudder
attachment system and the
bumper on the front. Our
model held up well in testing
until our second test with the
60 degree rudder, when the
fuselage snapped at a weak
point.

10. Data
Rudder Trial # Distance Flight Damage Wind Speed and
Flown Time Report direction
180 degree 1 80’8” 2.8 seconds Tail bent almost 180 degrees North, 12 mph
rudder
(control)
2 77’ 2.7 seconds Tail bent about 90 degrees North, 12 mph
3 136’2” 3.4 seconds Tail folded vertically in half Northwest, 9 mph
4 106’4” 3.0 seconds Tail bent slightly, wings ripped Northwest, 9 mph
60 degree 1 97’2” 2.6 seconds No damage taken Northwest, 9 mph
rudder
2 97’2” 2.6 seconds Fuselage snapped, forcibly concluding Northwest, 9 mph
testing
3 N/A N/A Unable to continue testing N/A
4 N/A N/A Unable to continue testing N/A
All launches were done at 55 PSI with a cannon height of 103 inches.

11. Results
We found that the 180 degree (flat) rudder made
the glider travel farther, with an average flight distance
that was 34.5 inches greater than the 60 degree rudder
and an average flight time that was 3/8 of a second
longer. We think that this is because the 180 did not
provide as much air resistance as the 60 degree rudder.
We originally thought that the air resistance from the 60
degree rudder would balance the plane, but it ended up
overbalancing it instead.

12. Error Analysis
In our experiment, although we tried to be as accurate as
possible, there was room for error. Some errors that could have affected
the results are:
 Distance: When we measured flight distance, we counted paces. We
put the pace length at 22 inches, although the length varied slightly
with each stride.
 Wind speed/direction: we took the wind speed and direction from an
online weather report as we lacked the equipment to measure them
ourselves.
 Rudders: as shown in our data, our rudders were damaged in some
tests. We lacked the material to built a rudder for each test, so we
reused those that were damaged, doing our best to repair them without
adding new materials.
 Flight time: we used a handheld timer and had to estimate when the
plane left the barrel of the cannon, as well as when it landed.

13. Conclusion
A flat (180 degree) rudder creates more balance
for a glider, allowing it to fly farther and longer than a
rudder that is at an angle. It also creates less air
resistance.
THE END