Attack on Bin Laden Used Stealthy Helicopter That Had Been a Secret

The assault team that killed Osama bin Laden sneaked up on his compound in radar-evading helicopters that had never been discussed publicly by the United States government, aviation analysts said Thursday. - Attack on Bin Laden Used Stealthy Helicopter That Had Been a Secret
Data Show Bin Laden Plots; C.I.A. Hid Near Raided House - nytimes