The 1910 Fokker “Spin”
An historic aircraft worth modeling
Anthony Fokker was a Dutch aviation pioneer who designed, developed and manufactured numerous historical aircraft in the first decades of powered flight. Many of the top German fighter aircraft that flew during World War I, such as the E.III Eindecker, Dr.I Triplane, Fokker D.VII and Fokker D.VIII began at the drawing board of Anthony Fokker. After the war Fokker went on to develop civilian aircraft in the Netherlands and the United States.
Anthony Fokker was always interested in mechanical things. His focus in aviation was sparked by the Wright brothers’ exhibition flights in France during the summer of 1908. Fokker formed a partnership with two colleagues and proceeded to build their first aircraft which they nicknamed “de Spin.” Spin is the Dutch word for spider. This seemed an appropriate moniker due to the abundance of flying wires that held the aircraft structure together.
Fokker and his colleagues literally had to conceive and build the Spin in 1910 on their own and then teach themselves how to fly. Aeronautical knowledge was rudimentary seven years after the Wright’s first flight and no one had a true set of design guidelines.
The Spin employed an uncomplicated layout of a flat wood frame that permitted wing, landing gear and tail surface attachment, as well as a mount for the water cooled motor and the pilot’s seat. Surprisingly, the first Spin did not employ any sort of rudder. The flight control plan was to use the slight sweep of the wings to somehow provide lateral control.
Initial tests showed that a rudder was needed for directional control. Ailerons were included in some later versions. Fokker and his partners build three variants of the Spin incorporating lessons learned from various hops, flights and crashes. Changes included increasing the strength of the wing cabane strut, location of the pilot seat, strengthening the landing gear and reducing fuselage weight via milling the wood structure.
Fokker used the second Spin to teach himself how to fly. He managed to coax the Spin into gentle turns and eventually full circles, earning his pilot’s certificate in summer 1911 when he was 21 years old.
Self-promotion was a key part of any aircraft designer’s life in those early days, and Fokker was well aware of this requirement. Fokker became a celebrity in the Netherlands on August 31, 1911 by flying his third Spin around the tower of Sint-Bavokerk in Harlem. August 31st was just by coincidence the birthday of Dutch Queen Wilhelmina.
Center of gravity considerations
The Fokker Spin would make a great candidate for a scale radio control model plane. The Spin’s design is unique, but not overly complicated to build as an RC model. At first inspection my only concern is that the nose moment is a bit short. My input would be to lengthen the nose slightly for an RC version to help properly locate the center of gravity.
The wing has a slight sweep, which is unusual but adds character to the model and will not harm flight performance. The horizontal tail surfaces seem to have plenty of surface area and should provide a positive pitch control response. There is essentially no fin, and the rudder looks smaller than desired. My recommendation is to make the rudder slightly larger for a model. This will ensure positive turn control as well as adding needed side area for lateral stability.
The Spin’s wings have a simple two spar design. This was all that was required due to the extensive flying wire bracing. For an RC model the spars will need to be quite strong as they will bear the entire weight of the wing as well as flight loads. Plywood reinforcement of the balsa wing spars could be used as with the Blackburn. Embedded carbon rods would be another way to provide the needed wing spar strength. I would assume that for a smaller flying model of the Spin the airframe rigging wires would be for decoration, and not part of the airplane’s structure.
Early aircraft designs like the Spin were underpowered due to the engine technology of the day. Wings were set at a surprising large positive incidence. This was a common practice for many aircraft in that era such as the Bleriot. Based on my test flight experience with models of the Blackburn and Chickadee, I recommend that you keep a slight amount of positive incidence for any model you design of the Spin. For the slow flight speeds of this type of aircraft the positive incidence works out well.
Landing gear details
The Spin’s landing gear is distinctive and functional and does not look difficult to replicate. The electric motor will be easy to install in the fuselage frame. As discussed earlier, I would extend the nose a bit to help keep the center of gravity within limits. In line with this approach, keep all the electronics and the battery as far forward as possible.
The Spin is essentially what we would call today an ultralight aircraft. Many of the same features we see in ultralight aircraft – fabric covering, functional wiring bracing and a short nose moment – are part of the Spin’s design.
The Spin is an historic aircraft well worth modeling. The visual emphasis points would be a detailed engine put in place over the electric motor and a full set of rigging and flying wires. Good luck with your model airplane design of the Fokker Spin!
Author: Gordon McKay