Seal Team Six: The Raid on Osama Bin Laden

The soft crash of the helicopter in the bin Laden compound was caused by what is called a vortex ring state. This happens when the air from the downwash of the propeller blades swirls up and cycles back down through the blades. In essence, the helicopter is descending through a downrush of air that cycles up back through the blades, which raises the pressure of the air passing over the top of the blades, thereby reducing lift. This was partly caused by the enclosing walls of the landing area that caused the air to hit the ground, be pushed towards the walls, then directed up the walls and sucked back into the blades. As the helicopter dropped, the tail hit the top of a wall and it began to roll, at which time the pilot put the nose down so that the helicopter would not roll over onto its side. It came to rest with the nose down at a 45º angle. The occupants sustained no serious injuries.

The two helicopters used in the raid were highly modified Sikorsky MH-60 Blackhawks, equipped with sharply angled anti-radar stealth cladding, but the helicopters in the movie appear to be standard Blackhawks.

Featured in Seal Team Six: The Raid on Osama Bin Laden - Behind the Scenes (2013)