Once the hijackers noticed the boarding stairs moving towards them, they recognised the imminent assault. Through the cockpit window, a hijacker fired upon the stairs containing the forward GIGN team. As the first stairs reached the front starboard (right) door, it became apparent that it was elevated too high relative to the door frame for a uniform entry into the aircraft. The GIGN had trained on an empty aircraft, in which the suspension system of the plane was not as compressed, leading to an overestimation of the necessary height of the boarding stairs. After a short delay in repositioning the stairs, GIGN forces were able to enter. The hijackers returned fire, attacking the GIGN forces. One hijacker was killed instantly. Then, the two other units entered the rear of the aircraft. The participants fired hundreds of bullets. The hijackers fired through the skin of the aircraft. Grenades erupted and smoke went through the cabin. The GIGN's concussion grenades temporarily blinded and deafened occupants, allowing the GIGN to storm the aircraft. One of the hijackers' homemade grenades detonated, causing limited damage. The snipers on the tower could not get a clear shot into the aircraft as the copilot, Jean-Paul Borderie, blocked their view. Through a window, Borderie jumped out of the cockpit and staggered away. With the view unobstructed, the snipers began firing into the cockpit, while the GIGN evacuated passengers in the rear of the aircraft.