This spring, powerful gusts and icy crosswinds transformed the skies of northwest Indiana into a high-stakes physics laboratory for Notre Dame’s Senior Aerospace Design students, putting their custom-built RC aircraft to the test.
The flight tests took place on a runway owned by the South Bend Radio Control Club (SBRC). SBRC’s partnership with Notre Dame’s aerospace program has spanned thirty years, with veteran club members mentoring students in the art of building small-scale aircraft.
To complete their flight tests successfully, the students’ planes had to navigate a pre-determined flight path that included two 180-degree turns and one full 360-degree turn. Scoring figured in take-off distances, lap times, and golf-ball payloads, as well as construction costs and demonstrations of aerial agility.
Associate Professor in Aerospace and Mechanical Engineering Hirotaka Sakaue, who teaches the senior design class, added a data collection requirement this year. “Flight tests provide an opportunity to collect data and then compare it with predicted results,” said Sakaue. “When there’s a disconnect between the two, it’s important for the students to be able to explain why.”
Onboard sensors captured real-time data on wind speed, direction, air pressure, temperature, and GPS coordinates, which students then processed using MATLAB and Python to better understand their aircraft’s performance.
Scientific predictions frequently collided head-on with unpredictable winds on the runway. “It’s been pretty tumultuous,” said senior Jackson O’Neill, describing his team’s experience. “Our first flight was a ‘trim flight’—pretty lackadaisical and lazy—and it performed nominally.” In the world of engineering, that is high praise for a stable, predictable aircraft. However, the team’s plane lost elevator control during its second flight, sending it into a headlong descent that planted its nose deep into the Indiana turf. By shortening the wings to add agility and adding an aluminum coupling for reinforcement, the team’s battle-hardened plane rose again, thrilling the crowd with barrel rolls and loop de loops.
Their actual constructed planes, students discovered, did not always behave like their computer-designed twins. “The biggest thing that we learned was that the SolidWorks model that we made in CAD wasn’t accurately reflecting where the center of gravity was going to be,” said senior Monique Morse. “So, we should have paid more attention to basic physics and theoretical design when we started. You can’t fully rely on something digital.”
Imagination and engineering savvy blended seamlessly in many designs. A shark-inspired plane, with team members sporting shark costumes, paired sleek wings with a custom fin antenna for a secure and vibration-free sensor mount; a hot pink plane (a.k.a. “Low Drag Queen”) deemed “too glam to stall” claimed the first stable V-tail in class history; and an ultra-light fuselage whistled in flight.
“Yeah, it’s been ugly weather this year. A lot of cold, wet wind,” said Robert Kistler, long-time SBRC member and class mentor. But on the last day, as students and mentors watched a biplane soar into a calm, robin-egg-blue sky, it was clear that all those hours in the workshop were finally paying off.
—Karla Cruise, Notre Dame Engineering. Photos by Wes Evard, Notre Dame Engineering.