April 25, 2007
The University of Texas at Austin placed 6th among 50 entrants in this year’s Design, Build, Fly (DBF) Competition, an international competition in which college students design and build remote controlled aircraft to complete different missions. The Channel 4 News Team, named for the movie Anchorman, took the top UT score, while Flipper, named for her really short wings, tried hard, but did not quite make the top ten.
This year’s competition involved flying with two separate payloads, one weighing three pounds and the other five pounds, as well as performing ground missions in which the airplane was assembled and payloads switched. The scoring system favored light weight aircraft with short wing spans. When the 2006/2007 DBF competition rules were posted last August, both teams began working on the project. Team members were organized into subgroups to design the aircrafts’ structure and propulsion systems and analyze aerodynamic performance and stability and sizing. Computer aided drawing was used to assist with the design.
The Channel 4 News Team prototype aircraft was completed in February and test flown several times in order to optimize the design. The competition aircraft was completed the evening before leaving for the competition. Technical inspections were done the first day and the aircraft was deemed competition worthy. The least challenging flight mission was attempted first, and the aircraft took off within 100 feet complete with the three pound payload, flying twice around a 1000 foot long track. Overall, the aircraft was well trimmed out, statically stable, structurally sound and had the required power to complete the mission.
The next day, the team planned to complete the two ground missions, and attempt the second flight mission with the five pound payload. The ground missions were completed successfully, but the pilot lost control during the flight mission and the aircraft crashed. In switching the payloads, the aircraft’s center of gravity had been moved forward by half an inch, a minor change the team overlooked as negligible. The center of gravity change made the aircraft nose heavy and difficult to maintain in steady level flight.
With three hours left until the end of the competition and against all odds, the team rebuilt the aircraft and attempted to redo the second mission. Due to unfavorable winds, an aborted takeoff attempt resulted in damage to the nose landing gear and wings. In spite of this The Channel 4 News Team placed 6th out of 50 teams signed up to compete. The team’s success was a reward for its hard work, and future teams will strive to improve on this.
Designs for Flipper began last fall and its first test flight took place in December. Throughout the competition, the aircraft crashed and students learned and rebuilt. Flipper was not alone—in fact every aircraft that placed in the top five crashed at least once. Flipper was a competitive aircraft and could have easily placed among the top five with one successful flight. Team members are confident that next year’s team will place in the top three.
