Publish Date: 24.04.2019

Category: News from the University

A team of 17 students from the Faculty of Mechanical Engineering, University of Ljubljana, secured a clear-cut victory in operating a remote-controlled unmanned aircraft at the Design/Build/Fly competition held in the United States of America. The team successfully designed and built an extremely fast and light composite aircraft that can reach speeds of over 100 km/h and is capable of flying at the competitive speed for more than 10 minutes. With over 100 universities participating, the Slovenian team surpassed renowned universities such as MIT, Stanford University, University of Southern California, Georgia Institute of Technology, University of Hong Kong, Virginia Tech, etc.

Every year, the American Institute of Aeronautics and Astronautics (AIAA) invites students to design and build a radio-controlled unmanned aircraft. This year, the competition was held from 11 to 14 April 2019 in Tucson, Arizona, and the team of students from the Faculty of Mechanical Engineering, University of Ljubljana, took part under the mentorship of Asst Prof Viktor Šajn.

The preparations for the event took over 6 months and involved building a model aircraft with radar that could take off from an aircraft carrier as per instructions. In addition to imposing restrictions on dimensions, the guidelines required folding wings that spread automatically, as well as the options of radar rotation and bomb dropping. The teams had to build an aircraft that can carry as many “bombs” as possible, that can take off from a 3-metre platform at great speed, and that can be prepared for take-off quickly. The team, which was led by the engineering student Timotej Hofbauer, decided to build their aircraft entirely from composites with the help of major sponsors (Pipistrel, Akrapovič and Zavod404). 

“We have been building the aircraft for more than 6 months and committed over 2000 hours of work to it. We succeeded in building an incredibly fast and light composite aircraft that can reach speeds of over 100 km/h and is capable of flying at the competitive speed for over 10 minutes. The ready-to-fly aircraft weighs approximately 9 kg, of which 35% make up the batteries alone. It can carry 18 “bombs” and has a wingspan of 2.5 metres,” said the aircraft’s operator Hofbauer about its technical specifications.

The competition, which took place in the desert, comprised three flights and a ground mission. In the ground mission, our students achieved remarkable speed due to the wing-spreading system that functions based on the torsion spring principle. The first flight confirmed that the aircraft is capable of completing three laps around the course. The second mission saw them surpassing all universities as the aircraft’s excellent surface featuring mounted radar enabled them to complete all three laps in 1 minute and 29 seconds. The third mission brought the highest number of points. “This was where we increased our lead. Within 10 minutes, we succeeded in completing a record 18 laps and dropping 18 “bombs”, which is 4 laps more than the runner-up team. This made us the absolute winners,” said Hofbauer and added that the team was surprised at having achieved such an advantage. “We were all very surprised at having managed to take such a lead compared to the other universities.”

Mitjan Kalin, the Dean of the Faculty of Engineering, was also very pleased with the superb result. “The team’s success is the result of knowledge, diligence and hard work. I am glad and proud that the students are able to show in this manner that they are capable of reaching the very top despite the disparity in material conditions between respective universities. Our faculty strives to provide for our students to the best of our abilities.”

This year, the team was presented with the greatest challenge thus far, as they were building an aircraft that was very large compared to the previous model. In addition, huge moulds had to be made, and the problem of requiring adequate space was solved by securing a workshop of Zavod404. Despite all these challenges, the team succeeded in completing two prototypes in six months, along with the final aircraft, with no major problems, and further proving their knowledge and excellent level of preparation at the competition. Every year, the team strives to improve the manufacturing technology. These efforts are greatly supported by sponsors, to whom the team would like to thank for the opportunity extended and all the help provided.