Abstract: On July 29, 2005, Employee #1 and two coworkers were assigned to move an aircraft from an overnight area to the gate. Employee #1, an aircraft brake operator, controlled the airplane from inside the cockpit. The coworkers were a guideman, who operated the tow tractor to pull the airplane to the gate, and a wing walker, who operated the push back tug and watched the blindside of the airplane as it was being relocated. The aircraft was parked in the remain overnight area. The guideman pushed the portable staircase, Wasp Model Number AO4836D, to the airplane. Employee #1 then attached the staircase to the rear of the tow tractor and walked up the staircase to enter the aircraft. Employee #1 tried to open the airplane door, and did not get enough leverage to completely open it. The door opened only half-way. Employee #1 thought that too much force was required for opening the door. He did not want to risk an injury, so he closed the door to try to open the door again with better leverage. As he did this, the guideman thought he was inside the airplane, and drove the stairs away. Employee #1 was still at the top of the stairs and lost his balance, falling 14 ft. He sustained a shattered right elbow (compound fracture) and hairline fracture of the pelvis/hip. Employee #1 was transported to a medical center, where he was hospitalized.