The helicopter that crashed during the raid on Osama bin Laden's compound earlier this week was a stealth design that the US government had kept secret, according to aviation experts. The military is still keeping mum and the SEALs---keeping with protocol---burned the aircraft after it went down. But information gleaned from photos of the surviving tailboom (the part that holds the rear rotor) and clues from other stealth aircraft suggest the helicopter was an H-60 Blackhawk, heavily modified to escape radar detection and fly more quietly---explaining why Pakistani air forces didn't detect the helicopters. How the Heck: To the experts' eyes, several unusual features marked the helicopter as a never-before-discussed stealth model.