Repairs took two weeks, but the next flight attempt also ended in a crash, necessitating a further two weeks of repair work. On June 21 three flights without any breakages were achieved, but four days later the aircraft crashed again. These accidents were caused by the aircraft's pitch instability. Suspecting that this was caused by the centre of gravity being too far forward, they moved the engine and pilot position back, but this made matters worse. The machine would undulate unless the front elevator was depressed, but this created additional drag, and so they added of iron bars as ballast under the elevators, which were also enlarged. So modified, 24 flights were made in August, including two on August 22 of a quarter of a mile, the greatest distance that they could fly without having to make a turn.