Today we continue our coverage of the 2013 IgNobel Prizes with the Safety Engineering Prize! Sadly, the author of the patent for this prize has since passed on. But it doesn't make the prize itself any less deserved.
US Patent #3811643, Gustano A. Pizzo, "anti hijacking system for aircraft", May 21, 1972.
So...what is it? It's an antihijacking system for aircraft. The idea is that the hijacker (presumably after being caught by the crew, there's no mention of this first bit), is placed in a special compartment behind the captain's area. The compartment floor has a hatch, which opens and drops the hijacker into a net. The net then gets dropped into a parachute. The newly-installed bomb-bay doors on the bottom of the plane open, and the hapless hijacker is parachuted to the ground, where the police, having been alerted by radio, pick him up.
The original patent was filed in 1974, so I'm sure if it were implemented now (if all planes could be retrofitted with bomb-bay doors and strategically positioned nets), you could add things like a GPS tracker so the parachute could be tracked, maybe a floatation device in case he was released over the ocean, etc. But when it comes down to cases, it looks like the original catching of the hijacker is still up to us.