The goal of the Quantity Challenge, hosted by the British Model Flying Association‘s Quantity Challenge, is to design UAVs that can carry the maximum possible payload volume- as 150mm polystyrene spheres.

The this project was started in the 2020-21 academic year. The plan was to build not one, but two different design concepts, namely the Blended Wing Body (BWB) and the Conventional (CONV) configuration.

The conventional aircraft concept.

The Blended Wing Body concept.

Design

We wanted our aircraft to carry as much volume – 15 foam spheres to be exact (or 4 footballs)- as quickly as possible! All design work centered around this design philosophy.

Both the BWB and CONV are aerodynamically optimized aircraft. Namely, the fuselage of the BWB is designed to act as a lifting body- further generating lift.

Conventional aircraft concept XFLR5 model

Blended wing body XFLR5 model

Our aircraft must have strong, lightweight structures to withstand loading during flights and the occasional hard landing. Bearing that in mind, the wing was designed as a glueless jigsaw puzzle, with interlocking carbon-fiber spars and balsa wood ribs. The gigantic, volume-carrying fuselages are also well-reinforced with carbon fiber longerons, formers, and skin plates. Countless smaller mechanisms are present in the aircraft. An example is the steerable nose-wheel assembly tailored for pilot control during taxi.

What good is an aircraft without proper controls? Large servo-actuated elevators/rudders/ailerons are integrated onto the aircraft.

Production

An novel wet-up technique was implemented on carbon fiber to achieve the intricate internal structure. Balsa wood was put on structures with a smaller load requirement. The best way to cover the aircraft was with shrink foil- a stretchable, light plastic that naturally adhesions to the base structure.

Status

After some flight tests and a lack of time it was decided to put these aircraft on hold. The aircraft did not end up competing in the competition.