Camp had barely been established when torrential rains swept the Outer Banks for a solid week. This was followed by the worst outbreak of mosquitoes in a number of years. The mosquitoes were relentless, there was no escaping them. They were so bad, they bit completely through clothes, leaving giant bumps all over everyone's body. The mosquitoes finally disappeared, but Orville and Wilbur's troubles were not over.

After they had assembled the glider they were disappointed to find that it refused to fly as well as the previous year's model. At times it seemed to be completely out of control. They had designed the wings from the air-pressure tables published by Otto Lilienthal, but the wings did not have anywhere near the lifting power they had expected. To make matters worse, the movable part of the wing was not working as it should. This was the part of the wing that controlled the up and down movements; it was not working as effectively as expected either.

They stopped testing and began making design changes. These adjustments helped the movable part of the wing to work properly, but the glider still would not lift off and perform as Lilienthal's tables predicted. After Wilbur received a black eye, facial cuts, and several bruises, they gave up trying to fly themselves and just flew the glider as an unmanned kite. When the rains returned the brother spirits plunged along with the weather, so they closed up camp a lot sooner than they had planned and returned home.

Back in Dayton, discouraged, Orville and Wilbur begin speculating on their problems. They decided that the calculations that they had been relying on were not correct, so they threw them all out and decided to undertake their own investigations.

First, they built a wind tunnel, with a glass-viewing window, that used a fan to create wind. It was not the first wind tunnel ever built, but it was the first to be used in the study of aerodynamics. They spent several weeks testing wings and making their own calculations. As always, the Wright brothers kept meticulous notes, especially since they knew they were exploring uncharted territory. When their lab tests were complete, they felt confident that they could calculate what the performance of a wing would be, before they ever built and tested it.

Armed with the new knowledge, they designed and built their biggest glider yet. The wings, were longer and narrower, thirty-two feet long, by five feet wide. They also, added two 6-foot high vertical fins and a tail to help stabilize the glider during turns. The hip cradle would be the same as the previous year. All together the machine weighed just under 120 pounds. Wilbur sewed the cloth for the wings, assisted by Orville.

Back on the Outer Banks by the end of August, 1902, surrounded by their many trunks, crates of supplies and glider parts, the brothers discovered that the winter winds had damaged the wooden storage shed they had built the previous year. It took them until the middle of September to set up and repair their camp and assemble the new glider.