Originally Posted by Andrewmcm
I think there are crossed wires here. There are two main instances in which cars may become airborne through contact with another car. The first is interlocking wheels, where the rotation of the wheels on each car forces one to mount the other, resulting in lift off of the affected car (i.e. Kenny Brack and Ryan Briscoe). The second is where the closing rate of the car behind is so great that its chassis makes contact with the car in front, and the rearmost car is launched into the air.
I'm not overly keen on watching replays of Sunday's incident, but I'm fairly sure that Wheldon, Power and Mann were all airborne because they were effectively launched owing to their relatively high rate of closing. Bumpers around the rear wheels may not have helped much in this case. As I said above the best way to avoid mayhem like Sunday is to avoid a rules package that puts the cars in those circumstances in the first place.