After connecting the new version of the cardboard wings to the main body, it was time to perform some initial flight tests. Before making the trek to E7, some initial stability tests were performed in the hallway outside of our workspace. The first attempt was highly unstable, spinning backward very quickly. In order to compensate, some mass (in the form of bags of rice) was added to the front of the glider to move the center of mass forward and improve stability.
As you can see, the performance was better than previously described, but still quite unstable without any control input. To further improve passive stability, more weight was added to the nose to further adjust the center of mass.
This provided a much more stable aircraft, however the lack of space made any further testing here useless. We then moved to the Engineering 7 atrium where we would have the verticality to better observe flight characteristics using the RC transmitter and receiver used previously for the foam wing.
The first of the tests performed there was the most exciting, doing a complete nose-dive towards the ground, before pulling up at the last second to glide a reasonable distance.
At this point, it appeared that there was perhaps too much mass at the nose for sustained flight, so some of the rice was removed. We then performed another test to see the effect on flight stability.
This prevented the near-fatal nosedive, at the expense of the traversal distance of the previous test.
With these experiments, we believe that the control surfaces on the glider are insufficient to generate sufficient aerodynamic moment. In addition, although the straight wings generate more lift, swept wings would likely be a good tool to move the center of aerodynamic force away from the center of mass, further improving stability. Hence, another iteration of the cardboard glider will be created, using swept wings and larger control surfaces to improve in-flight stability.
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