Designing an aircraft for BMFA Payload Challenge was the flagship project of Lambach Aircraft in the 2023-2024 academic year. We assembled a strong team of 8, consisting of motivated bachelor and master Aerospace Engineering students. Furthermore, most of the members had past experience designing and flying UAVs. We placed an admirable 4th out of 16 international competing teams, with the lightest flying aircraft.
The Competition
BMFA Payload Challenge is an annual competition organized by the British Model Flying Association and conducted in the association’s National Centre near Grantham in Lincolnshire on 12th – 13th of June. Teams from different universities all around the world assemble to take part in the competition. That includes students from prestigious universities like Technical University of Munich, Beihang University, Hebei University of Science and Technology and many more. Teams are required to built and fly a load-carrying model aircraft with a payload of 4 kg of water. The competitors are judged based on flight performance, technical drawings, report and presentation. The main challenge is to design an aircraft with a lowest possible structural weight.
The Aircraft
After thorough analysis and discussion of the competition content, several draft designs, including the flying-wing, tandem, canard, and conventional configurations, were identified. By leveraging the advantages of these drafts, a super high load-weight ratio design was proposed. This design incorporates a novel high-lift four-lifting-surface canard aerodynamic configuration. For 2 months our team worked tirelessly on the aircraft and payload bay aerodynamic design, as well as the detailed structure design. Over 100 hours of CFD analysis using ANSYS Fluent were performed to optimize the design’s performance
An initial prototype was constructed out of foam to the same dimensions as the final iteration of the design. It was used to test the aircraft’s flight performance and dynamics under real-world conditions, due to the limitations of computational modeling.
This prototype provided us with invaluable knowledge of the final configuration, enabling us to move towards our finished design confident that it was aerodynamically and structurally robust, even under actual testing in harsh conditions.
The prototype weighed approximately 800 grams, with the aircraft’s fuselage structure identical to the finished product. Testing was conducted at Valkenburg Airfield by members of the BMFA team.
Our finished aircraft was constructed out of a composite skin and truss-based ultra-light wing structure. The payload tank was hollow and also made out of a composite. Our final weight was 890 grams.
The final aircraft uses hollow carbon fiber rods as a fuselage, and landing gear supports, as well as thin solid carbon fiber stressed members of the truss structure. From testing using the prototype, the winglet endplates were discarded.
The ailerons and elevators are made out of foam, as they do not need to deal with large aerodynamic forces. This is due to the low mass of the combined aircraft and payload package.
