Santos-Dumont 14-bis
Some people, especially in Brazil, believe the 14-bis was the first airplane to fly, before the Wright Brothers' Flyer.  The main reason for this is that although the Wright Brothers flew the Flyer at Kitty Hawk in 1903, they did not tell many people about it right away.  Europeans saw Alberto Santos-Dumont fly the 14-bis in 1906 before they heard about the Wrights flying the Flyer in 1903.  This was because the Wright Brothers hoped to patent their work and make money, so they kept most of their experiments a secret.  Alberto Santos Dumont was not trying to make money, so he invited almost anyone who wanted to come watch him work.  However, the Wright Brothers did invite witnesses to their first flight at Kitty Hawk in 1903 to watch and take a photograph.  By 1906, the Wright Brothers had flown many of their planes many times, for as far as 39 kilometers. Today, most aviation historians believe that the 14-bis was not the first plane to fly.