This year's DBF requirement was to design a plane that fits in a box of max dimension (L+W+H  <= 62 in) and has to be assembled under 5 minutes for all missions. 

Mission-1 was with flying under 5 minutes with no payload. Mission-2 is flying as many laps with min 30% MGTW payload under 10-minutes. Mission-3 is flying 3-laps with Jamming antenna in 5 minutes.

Behold the all new WooHawk RC plane, designed and manufactured by Illinois Tech students for the year 2022 AIAA-DBF competition. The main objective of the 2022 AIAA DBF contest is to design a vaccine delivery drone. The rules con- strain wing geometry and takeoff distance. Three flight missions and one ground mission comprise the contest. 

Aa trapezoidal wing was determined to be the best choice to accomplish the desired elliptic lift distribution, whilst being easy to manufacture.To accomplish this, a handful of known and custom airfoils were selected in order to determine the best performing airfoil based on Clmax.

The selected airfoil was Clark Y due to previous competition winning designs, ease of manufacturing, and good Cl vs Alpha and Cl/Cd vs Alpha performance. The airfoils under consideration were to have a relatively high lift coefficient at low angles of attack. The thickness of the airfoils for the wings was to be 12-16 %, and about 13% for the tail.

Our system would utilize a rack and pinion system in combination with two servo driven doors to allow for the pilot to have complete control of the system with minimal possibility of mechanical failure. The pilot would turn on the rack and pinion once the first lap is completed and the system would remain on until the 10 minutes allotted had passed.

To minimize the structural weight of the wing, a balsa and plywood build with a tensile outer skin was utilized. The main structural member is an I-beam spar with vertically mounted plywood for increased rigidity reduce weight. 

Propulsion endurance test by measuring voltage over time. Voltage was read at approximately 1-minute increments using a multi-meter to evaluate the discharge rate of the battery.

To counteract the stress concentration at the center of the fuselage due to the wing, we decided to integrate the middle section of the wing into the fuselage for better stress pathing and ease of wing installment. 

Here's FEA analysis of the von mises stress at maximum loading, corresponding to the maximum deflection of the center spar. By looking up mechanical properties for carbon fiber, we can find the factor of safety given the max von mises stress.

In order to maximize the flight score for the competition a rigorous understanding of the rules and mission requirements was crucial. As per the competition rules, this year’s mission is to develop a banner towing bush aircraft. The mission requirements drive majority of the design parameters. Based upon the constraints such as wingspan, banner length, and payload weight, the best aircraft configuration was selected.

he fuselage was simulated with plywood properties imported from MATWEB. The focus of this analysis was to observe torsional rigidity and stress concentrations. This can be seen in  the firgure above. Predicted stress concentration zones were then reinforced until deemed satisfactory during manufacturing. Force was assumed to focus around quarter chord, and as such a single spar was chosen to simplify the shear center calculations. 

Bending moment and shear stress were also assumed to be ideally transferred. The inboard section consists of a half inch diameter rod, and the two outboard sections consist of a balsa and plywood I-beam. A Propulsion Test was done to evaluate the endurance of the proposed motors for the aircraft by recording the amount of Voltage over Time. The motors were mounted to a stand with a propeller attached. The throttle was set to reflect cruise power of the plane and then the motor was allowed to run. 

The wing was held at the tips and a bucket was hung in the middle of the wing. Water was slowly poured, increasing the applied force until failure. In addition, a hand wingtip test was done before every flight test to verify Cg and wing rigidity. 

Takeoff tests were integrated into flight testing, to ensure the aircraft can takeoff within the 20 ft Mission 1 and 3 restriction. This is to ensure the aircraft can takeoff regardless of wind conditions.