Hi Delia,
When I was at a folk festival in South Australia in October, I spotted this biplane flying over. It was a bit too far for even my P900 zoom to pick up any detail.
Can someone explain (in simple terms please) why this system of wings was developed and are they still producing such planes?
To fly at low speeds, which the early aviation pioneers attempted, requires a lot of wing area, and it was easier to provide a large, mechanically stable wing by creating a box-like structure comprising of two wings stacked on top of each other, connected by sturdy struts, and securely braced by criss-crossed wires.
Early on in aviation, the pioneers were often bird watchers, and their design usually resembled birds, and accordingly were monoplanes. Otto Lilienthal actually wrote a book on "Bird Flight as the Foundation for Artificial Flight", giving the best account of flapping bird flight ever produced up to that date.
The Wright brothers invented the practical airplane in biplane form because it was sturdier that way, but monoplanes were quite common into WW1, when biplanes became the standard form for their greater rigidity. (Ironically, the most popular monoplane, the German "Dove", did not owe its elegant wing shape to any bird, but rather to the "gliding" seeds of Alsomitra marcocarpa.)
An important factor for the rise of the biplane layout was that the monoplanes of that era weren't really resembling birds much - their wings had to be braced by dozens of wires too, which created so much drag you were better off with a biplane.
Biplanes are still made today, or produced in kit form and assembled by their owners, but I think all of these are used purely for recreational or sporting purposes.
Regards,
Henning