Ryan Cross
Design Build Fly aircraft on the runway

Design Build Fly

Every year, AIAA challenges students to show their creativity and technical expertise through the Design Build Fly competition. Rules are released in September with competition taking place in April.

I participated on the CU team for two years, joining as a member of the avionics team, then stepping up to lead the propulsion design and implementation team.

Ryan Cross explaining Design Build Fly at a student outreach event

2025

2025 Design Build Fly aircraft model

Goal: Design an aircraft, incorporated with removeable fuel tanks, to launch an X-1 test vehicle.

When I first started, I didn’t know the first thing about RC aircraft design. Terms like ESC and receiver frightened me.

So I learned.

I helped configure the avionics for our first prototype—now I know that an ESC regulates the power to the motor. I developed the tail block and sections of the fuselage in OnShape—now I can navigate CAD. I fabricated components using 3D printers, laser cutters, and CNC machines, bringing design to life with CAM.

My first year on CU DBF was my first exposure to applied, real world engineering. Following competition, I was left wanting more.

Original Design Build Fly crew with their aircraft in Tucson

2026

2026 Design Build Fly aircraft model

Goal: Design a banner-towing bush plane fitted with rubber duck passengers and hockey puck payloads.

Becoming a leader in engineering can be daunting: one must have technical and interpersonal skills to succeed. In learning and applying both skillsets through DBF, the club I had developed a passion for over the last year, I became energized.

I improved upon a MATLAB optimization code, working with the aerodynamics team to determine the most efficient motor and propeller combination. I validated this combination with a thrust test stand, involving new members with the hands on setup and calibration. Seeing the correlation between the model and hardware test data was invaluable.

Not only was I learning, but I was able to enhance the learning of other future engineers and leaders who would continue to build the team and beyond.

Design Build Fly team gathered with their aircraft

Ryan Cross, I just wanted to add something real quick here. You mentioned that you’re “not perfect” and that you sometimes struggle to keep everyone satisfied—but honestly, I think you’re doing a great job as Propulsion Lead. The support you give, the time you put in, and the friendly environment you create make a huge difference for all of us. It’s been really reassuring and motivating to work under someone who’s approachable and genuinely cares about keeping things moving in the right direction.

Leadership isn’t about being perfect; it’s about showing up, communicating, and giving your team confidence—and you’re nailing that. So kudos to you for everything you’ve done and continue to do. We appreciate it.

— Dinuka Hannadige, 2027 Test Lead

Check out the Colorado Design Build Fly website here: coloradodbf.org

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