 These are all twin-engine machines, except for the three-engined EH101.The commercial version of the T700 is the "CT7", with the engine used on the Bell 214ST (an enlarged version of the Huey), commercial Black Hawks, and the Sikorsky S-92 derivative of the Black Hawk, all of which are twin-engine helicopters.The CT7 turboprop variants use the same core as the turboshaft variants, with a propeller gearbox fitted forward of the core.