When it first made the scene in 1996, Cessna’s Citation X broke the mold by offering an unapologetic choice to those whose priority was speed—and lots of it. One look at its large 4,500-pounds-thrust Rolls Royce/Allison AE3007C engines and their oversize nacelles broadcast the message: Here’s a 528-knot, 3,450-nautical-mile, 51,000-foot fire-breather for those wanting to cover 3,000 nm with up to eight to nine passengers. With a maximum speed of 0.935 Mach it can cruise deep into the transonic speed range, coming enticingly close to the speed of sound.
Source: aopaProduction ceases for Cessna's speed demon