Abstract: On February 27, 1996, Employee #1, who worked for a large aircraft manufacturer in a large city, was standing on a 6 ft high contour ladder in the wing box area, drilling holes in an aircraft wing. He was holding a drill in one hand and an egg cup in the other when the ladder suddenly shifted to the right twice. The second time it happened, Employee #1 lost his balance and fell, with his right foot landing on a portion of a tool that was behind and to the side of the ladder. He sustained a dislocated ankle and a fractured right tibia and fibula, and underwent surgery to set his leg. The ladder, which was secured by a strap to the wing box support, remained upright after Employee #1 fell. It had rubber feet at its bottom and along the horizontal portion that was resting against the wing. The floor around the ladder had been level and clear, and no slippery substances were reported on the floor or the steps. Photos taken immediately after the accident showed the ladder to be at a 79 degree angle; the safety code specifies an angle of 76 degrees. A re-creation of the incident, based on the photos and testimony, determined that the ladder was at 77 degrees at the time of the accident. This was probably the result of the ladder strap being too short for the closest anchor point, meaning that it had to be extended to its maximum length and resulting in the ladder being a little too steep. The photos seem to indicate that the strap could have been secured to a closer location.