The Wright Flyer achieved the first successful flight of a heavier-than-air machine in 1903. Its engine was built by the Wright Brothers and their talented mechanic, Charlie Taylor. The engine had four water-cooled cylinders set in line, lying horizontally, a large flywheel and two gearwheels to drive the pusher propellers in opposite directions. The Wright's reported that the engine was 12 horsepower, but it is believed to have been nearer horsepower. People besides Orville and Wilbur Wright had been practising with gliders for many years, but these two brothers were the first to produce a plane that made a successful powered flight. On 17 December 1903, their biplane "The Flyer" flew for 12 seconds at a height of about three metres. Past glider pilots had steered their gliders by shifting around their body weight. But the Wright brothers came up with a more elegant solution: they twisted or warped the aircraft's wing tips in opposite directions to affect the airflow over the wings. That twist created different amounts of lift on each wing so that the aircraft would tilt toward one side. The pilot controlled the warping of the Wright Flyer's wing tips using wires connected to a hip cradle. That meant the pilot could steer by sliding his hips from side to side.