BluJay Endurance Aircraft
Rapid prototyping, flight testing, and production for a 3+ hour endurance airframe
Overview
As a researcher at Utah State University's Aggie Air Research Lab, I led the design and fabrication of BluJay, a fixed-wing unmanned aerial vehicle (UAV) engineered for extended endurance in remote sensing research missions. The core goal was to develop a platform that could achieve prolonged flight times while meeting operational requirements, such as pneumatic launcher deployment and belly-landing recovery. This demanded a careful balance between structural integrity to endure launch stresses and lightweight materials to facilitate slow-speed approaches, reducing impact forces and shortening ground roll distances.
I used computational fluid dynamics (CFD) to estimate the drag of the fuselage and lifting line theory to estimate aircraft aerodynamics performance and flight dynamics. Prototyping began with cost-effective foam models reinforced by strapping tape for rapid, real-world testing of the wing structure. Later, more advanced prototypes were built to validate the propulsion system. This iterative process uncovered key issues, like insufficient safety margins in the wing structure.
I documented the complete design and collaborated with a fabrication shop to create production tooling for the final hollow-core composite version. I also sized the propulsion system by selecting the motor, propeller, and batteries for peak performance. Prototype flight tests confirmed endurance of 3+ hours, exceeding mission needs.
The wall of my office during the configuration selection process.
Rendering of an early BluJay configuration that was not selected.
Image of fuselage CFD results. This was used to get a rough sense of the drag of the fuselage.
First foam and tape prototype that was used to validate the wing structure.
More refined foam and fiberglass prototype to validate propulsion system.
The pneumatic launcher was not ready for these flight tests, so we built a simple release system for vehicle launching.
The BluJay design and testing teams after a successful endurance test of 3+ hours.
The production version of BluJay and the design team.
BluJay at Airventure Oshkosh.
Accomplishments
- ✓Modeled and analyzed multiple aircraft configurations to select an optimal design balancing robustness, low-speed landing, and endurance.
- ✓Led the fabrication of multiple prototypes from low-fidelity foam/tape models to fiberglass and carbon fiber versions, validating over three hours of flight time in testing.
- ✓Optimized propulsion components (motor, propeller, batteries) and documented the design for handover to fabrication.
- ✓Diagnosed and resolved structural weaknesses in early wing designs, improving safety margins without adding excessive weight.
- ✓Created all the CAD models for the prototypes and production aircraft.
Lessons Learned
- •Low-cost rapid prototyping uncovers practical flaws that simulations alone might miss, enabling faster design validation.
- •Appropriate safety factors in composite structures are critical, as wing failures highlighted the risks of variability in real conditions.