For their new flyer, Orville and Wilbur decided to use two propellers, turning in the opposite directions to neutralized any twisting effect on the aircraft. The propellers were connected to the motor by a sprocket and chain transmission similar to the kind used on bicycles. The motor rested on the lower wing to the right of the pilot, so that it would not fall on him in case of an accident.

To balance the extra weight, the right wing was four inches longer than the left. The controls were comparable to the 1902 design, with a wingspan of slightly over forty feet; the new machine was the biggest one yet. In this latest design, only the rear of the wings would flex. For the first time the brothers gave their aircraft a name. They called it the Flyer.

With not enough room in their shop to put the flyer together, they had to wait until they got to the Outer Banks to assemble it for the first time. Wilbur and Orville arrived at Kill Devil Hills on September 25, 1903, where they once again had to repair their storm-damaged camp. This time, they not only made repairs, but put up a second building to be used as a workshop for assembling and housing the Flyer.

On good, windy days, they took out their old 1902 glider for practice flights. On calm or rainy days, they worked on the Flyer indoors. Progress was slowed because the propeller shafts and transmission sprocket wheel kept coming loose as the motor turned. The propeller shafts gave them so much trouble that Orville was forced to go back to Dayton to have new ones made. On the return train trip, Orville read in the newspaper that Samuel Piepont Langley's second and last attempt to launch a manned aircraft on December 8, 1903, had failed once again. Both Langley and the Great Aerodrome crashed into the cold waters of the Potomac River, taking $73,000 and Langley's hopes along with it.

Meanwhile, in Kitty Hawk, winter arrived early with rain, snow and freezing wind. Orville returned to Kill Devil Hills on December 11th. To launch the Flyer, they had built a movable rail for a starting track. The four, fifteen-foot wood sections of rail were covered with a thin metal strip on the top. For takeoff, the Flyer was placed over the track with its landing skids resting on a small two-wheeled dolly. The Flyer would then ride down the monorail on the dolly, into the wind until it gained enough airspeed to lift off and fly. Orville and Wilbur called the starting track the "Grand Junction Railroad".

They were finally ready for the first trials on Monday, December 14th, but the wind was not strong enough to launch from flat ground. Anxious to test the Flyer, Orville and Wilbur decided to try a downhill launch from the side of Kill Devil Hill. They ran the red signal flag to the top of the flagpole, alerting the lifesaving station a mile away that they were ready to begin. The lifesavers had agreed to be witnesses to the flight, and to help move the flying machine over the sand.

Before long, five men, two small boys and a dog came trudging up the beach.