The basic raw material in most AEROBAT propellers is
beech wood (Fagus sylvatica),
due to the straight, long fibres of trees up to forty metres high, with PEFC European eco-certificates guaranteeing that the forests where it comes from are sustainably managed. FSC certified sustainable forest.
The wood is cut, dried and stabilised specially for our purposes.
The beechwood laminates, between 10 and 15 millimeters thick, are joined together to form specific blocks for each job, paying careful attention to the shape and direction of the grain, the direction of rotation and the future specific design of each propeller.
Unlike other, artificial, materials, wood does not suffer structural fatigue under different tensile stresses, flexion and centrifugal force during the working of the propeller, because its fibres are just interlaced each other without forming more or less rigid crystals, as happens with metal alloys or synthetic resins, that crack with fatigue, causing fissures to appear in the former, and elastic properties to change in the latter. Wooden propellers are the only ones which have no life limit in terms of hours of operation.
The versatility which this noble material, wood, offers us, not being subject to using moulds, the experience gained in over twenty-five year's history of AEROBAT and the assistance of new technologies, allow us to adapt to the demands of any propeller for any engine.
In the manufacturing process we hardly generate any waste. The chips from the machines are collected and compressed automatically for use as biomass briquettes, solid fuel, with a high calorific value.
A very close Portuguese friend of mine, Leonardo Sayago, qualified as a naval engineer in England, and his first job was in a small boatyard, building and repairing pleasure craft made from composite materials.
One day a yacht arrived for repair, and Leonardo went to inform his boss, Angus Primrose, commenting that "it's made of wood, and as we can't do anything with that, I suppose we'll have to trash it...".
Angus immediately put him right, saying "Plastics are made by fools like you and me, but only God makes trees".