The Development of the Wright Flyer

As I sit here writing this article from Frankfurt Airport, watching the colossal A380s gracefully returning to solid ground,  I can’t help wonder how did humans manage to create this reality in such a short space of time? A little over a century ago the Wright Brothers conquered powered-controlled flight for the first time in human history. From wood and canvas to aluminium and carbon fibre, from primitive propellers to jet engines; The aviation industry has developed at an astonishing rate, but to really appreciate it I think it is important to look back at what the Wright Brothers and their predecessors achieved.

The Wright Brothers were the pioneers of flight, they left an indelible mark on the technological story of the human race when they conquered powered-controlled flight for the first time, but they are often portrayed as simple bike mechanics, neither of the brothers received any formal education in engineering or physics. So how did they become the poster children of engineering innovation?

The Wright Brother’s story began at a young age. The pair were fascinated with the dynamics of flight, their first introduction to aerodynamics was a small toy helicopter that their father bought them. They were fascinated with its mechanics and when it broke they figured out how it worked and fixed it, one of their first displays of the infamous “Knack”. They developed these skills over the course of their lives through their bicycle business, which also provided the capital and free-time they needed conquer flight.

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It is important to note that the brothers did not discover the principles of lift. Gliders had been in existence for some time before they developed the Wright Flyer, like any famous inventors the Wright brothers were standing on the shoulders of giants. Otto Lilienthal aka "The Glider King" was one of their many inspirations. Lilienthal had experimented extensively and released his lift test data to the public in the form of a beautifully illustrated book titled "Bird Flight as the Basis for Aviation" . This book set the foundations for the Wright Brother's achievements and upon learning of Otto's tragic death in a glider crash, they set out to improve the control mechanisms for flight.

Primitive controls for pitch and yaw (for a better understand of aircraft control you can watch my video below) had been developed for gliders, but no-one had managed to successfully control the roll of an aircraft. Previous inventors theorised that they could make the aircraft stable in roll with perfect weight distribution, but this does not allow the pilot to correct for sudden gusts of wind that would throw the aircraft off balance. Even more alarmingly early hand-gliders actually controlled their roll by using their own weight, a highly unstable form of control, as proven by the “Glider King” who died when he lost control of his glider when the angle of roll became too great to correct.

The need for a stable form of control was glaringly obvious to the brothers and in 1899 the pair tested their theory of wing warping by building a prototype in the form of a small kite. The test proved the theory and idea was further developed over the next two years with a series of gliders, both manned and unmanned. They were among the first people to witness the flight phenomenon such as wing stall and adverse yaw, which dismayed the brothers. Wilbur even stated that humans would not fly for another thousand years, but they did not stop, driven by their passion they persevered.

To help understand what was going on they developed their own aerodynamic test, believing the existing Lilienthal data was inadequate. They did this by building their own wind tunnel in their bike shop. They created hundreds of model wings and measured both lift and drag through various angles of attack. This allowed them to optimise their design and make some real improvements to the aircrafts configuration. A new aircraft was designed using the new data and it had significantly greater lift, despite the fact that the wing area was the same. The new design had a longer wingspan and its chord length was shorter, which increased lift while also decreasing drag.

They also added a rudder in the rear of the aircraft, which allowed them to counter-act adverse yaw. The brothers were solidifying themselves as one of the best problem solving teams in the world. This was the FIRST aircraft in the world to have control for all dimensions – roll, pitch and yaw, unsurprisingly it became a record holder for longest glide flight distance. Achieving a glide distance of 650 feet in 30 seconds. The next step was the addition of power.

This presented a number of new problems which the Brothers managed to solve once again. The first problem was manufacturing the custom engine for the aircraft. With no manufacturer volunteering to help, the brothers were forced to build and design the entire engine themselves. The unique nature of flight means a very lightweight engine is needed, the brothers calculated that they required an engine with an output of 8 horse power, but with a max weight of 200 pounds. They crafted a large amount of the engine from lightweight aluminium, which was also a first and a huge sign for things to come. Aluminium makes up 75-80% of modern aircraft and has only recently begun to see competition from carbon-fibre composites. On top of this they designed, tested and manufactured propellers blades, which they envisioned as sideways wings.  With these additions they made their first powered flights in 1903, with a maximum flight distance of 800 feet.

Their first flight was a momentous occasion, but not perfect. Their efforts were hampered by an unbalanced plane, which was caused by the addition of the engine. The engine was placed forward of the centre of gravity, causing the aircraft to pitch downwards and lose altitude. Thankfully they had pitch control which allowed them to correct the problem in flight. This resulted in a bobbing motion, continually gaining and losing altitude like a ship in heavy seas.  Maintaining flight took an immense amount of skill from the pilot and on the final flight of the day the aircraft crashed. The brothers returned to the drawing board to improve on the design.

They improved the power of the engine by increasing the bore and revised the rudder design. They also moved the engine towards the rear of the aircraft, but still did not manage perfect weight distribution. To solve this problem they added 70 pounds of weight to the front canard. This solved the problem, but added weight to the design and decreased performance. Once again the brothers returned to the drawing board and produced another design in 1905, which managed to achieve better balance by moving the fuel tank and radiator to the front of the aircraft. The rudder and elevators were increased in size and moved further from the centre of lift to provide additional torque, thus providing better control.

This design was their first truly practical plane and on October 5th 1905 Wilbur Wright flew 38 kilometres in 40 minutes. Four days later the brothers approached the US military to sell their design. Ten years later World War 1 was in full swing and aircraft were being used for war. The war provided the driving force to develop planes further and by the end of WW1 humans were on the verge of breaking into the stratosphere.

This is a companion article to my video "The Wright Brother Didn't Invent Flight". If you haven't seen it yet, please take a look.