Sikorsky built a helicopter in 2009 with record-setting speed, thanks to the coaxial rotors that spin in opposite directions. Now they want to build a version for the U.S. military, to be called the Raider S-97.

Sikorsky built a helicopter in 2009 with record-setting speed, thanks to the coaxial rotors that spin in opposite directions. Now they want to build a version for the U.S. military, to be called the Raider S-97.