GIANT FOAMBOARD AIRCRAFT PROJECT
GFA Mk. I
June 2022 saw the maiden flight of the first Giant Foamboard Aircraft but the journey to this milestone was long and winding.
Conception
The GFA project was born from a few weeks of brainstorming the potential of foamboard in aerostructure research. After some early experiments led to the development of very simple and surprisingly strong 'Perrin tube' structural members, the challenge to build a huge plane from the material began to form. The size of a foamboard structure is limited only by the savy of the designer.
Requirements
The CAA 'Open Category' limit of 20kg gave us a target and the challenge was laid down: how big can a 20kg aircraft get? A major constriction was that each component had to be made from 2D sheets of foamboard and should be easy to put together - this limits some of the geometry and manufacturing techniques. To speed up the design process, a very basic configuration was chosen with the simplest aerodynamics and aesthetics so structural considerations could come first. Simple modelling tools were used to define the size and shape of the aerodynamic surfaces and propulsion.
The Structure
Every detail of the aircraft was designed with weight saving in mind to maximise the overall size. Most pieces were drawn with holes in them and the non-load bearing skin was made from the thinnest film we could find. For the fuselage, a truss made up of Perrin tubes.
The main wing spar design was a point of enhanced consideration since this supports the entire weight of the aircraft. Eventually, a hollow, internally tapered design was formed made of 8 layers of foamboard. Our early modelling suggested this would just about be strong enough.
Final Design
Each design decision brought us closer to an end result. Eventually we converged on the simplest, largest design that met the requirements.
Flight Testing
A series of build days resulted in an airworthy structure we could take to the Llanbedr Airfield in Snowdonia. After some major surgery we began flight testing and were delighted to watch our foam beast climb safely into the air. Several successful flights were completed and the airframe survived three weeks of testing despite two emergency landings!