The Citation X: Science in Motion
Parked alongside other world-class private jets on an FBO runway, the Cessna Citation X stands out for its radical edges and streamlined design.
Mike Pierce, a 34-year veteran of Cessna Aviation (now part of Textron) who was part of the integrated team that designed this iconic aircraft, still can’t keep his inner aviation geek from aweing at the sight. “It’s long and lean with sleek swept wings and big powerful engines,” he says. “It just looks mean sitting on the ramp.”
Look past the surface, however, and it’s not just the design that’s so impressive, it’s the scientific intention behind the design. The Cessna Citation X is the fastest cross-continental business jet in the world, reaching a top speed of Mach 0.92 (700 mph) while consuming an average of 336 gallons per hour. (Not much more than other super mid-size jets—which average in the 250-270 range—considering the Citation X requires fewer hours to get you there). The bottom line: Efficiency is optimized in every possible aspect of the Citation X, allowing corporate executives to fly coast-to-coast in less than four hours, have their meetings, and return home by evening—all without paying exorbitantly higher operational costs.
“When we started this process, we were looking to do something that had never been done before in business jets,” Mike says, referring to the jet’s inception in the late 1980s. “Business jets had already seen long cabins, short-field runway performance, super docile handling characteristics, and single-pilot capability. We wanted to go after that speed number, and not just speed for the sake of speed, but speed with efficiency.”
The fastest business jets at the time were producing Mach 0.84 and, to exceed that, the Cessna team harnessed the power of two dual-channel, FADEC-controlled Rolls-Royce AE3007C2 turbo-fan engines. More than just raw force, Mike explains, “That specific engine is optimized to have a little more thrust at higher altitude and to do it efficiently.”
Even with efficient machinery, however, Cessna’s biggest obstacle was a simple matter of physics: the faster you go—especially as you exceed the low Mach 0.8s—the more drag you create. “Our challenge was to alleviate all that drag rise,” he says. “So if you look at the airplane, there are some pretty radical bends and curves, if you will.”
One of the most obvious instances is the fairing where the wing meets the fuselage. “The airplane actually curves inwards a bit right there,” Mike points out, “and that was done specifically to lower drag rise.”
Another is the angular shape of the airplane’s wings. There’s a 37-degree sweep on the leading edge of the wing, which makes it more aerodynamically efficient. “The less straight the wing is, the more speed you have,” says Mike. “So even on the tail, the horizontal stabilizer has a 40-degree leading edge sweep, which helps with lowering drag.”
After countless hours testing, iterating, and fine-tuning the aircraft, some design elements turned out markedly different than Cessna initially anticipated. The forward part of the fairing between wing and fuselage, for instance, looks a bit more blunt than one might expect it to. Though counter-intuitive, that was done to lower the drag over the middle part of the wing, allowing the aircraft to swiftly cut through air without impeding momentum.
“We [Cessna] rent more wind tunnel time than anyone else in general aviation,” says Mike, referencing countless hours spent testing design at places like NASA’s Langley Research Center in Virginia. “But on this airplane, we even exceeded what we normally do, to ensure this new concept was tested to the absolute max. No one had ever talked about cruising at Mach 0.92 so there was a lot of new ground to cover.”
Of course, not all the testing was done on the exterior; Cessna was equally adamant about the quality of the aircraft’s cabin. Says Mike, “We didn’t just want to create raw speed; we wanted to create the largest cabin in the traditional mid-size category and make it supremely comfortable.”
When you’re traveling at speeds of up to Mach 0.92, comfort first and foremost depends on how much the plane can reduce noise fatigue. And as opposed to stuffing the walls with insulation—which gets heavy and takes away room from the cabin—the Cessna team opted for a structural approach leveraging both interior and exterior design.
Externally, they ensured no part of the outside finish left any big gaps that could create noise, particularly around the belly of the airplane where the landing gear is. What’s more, they ensured seamless construction all the way down to the nuts and bolts. “If you have a bolt extending through a nut plate and it touches another part of the airplane,” Mike explains, “you actually have a noise transfer point from one part to another. So we were very careful to ensure that no bolts are touching each other.”
As for the interior, Cessna’s proprietary soundproofing system applies several layers of lithesome materials to minimize any noise coming from the outside. Combined with the plane’s ability to fly as high as 48,000 feet—which reduces fuel flow and allows pilots to find smoother air and better weather—it gives the world’s most powerful business jet an unfathomably quiet passenger experience. “It’s as quiet as any other jet I’ve flown,” he says.
That being said, a quiet flight experience means very little if the cabin itself isn’t equally refined. “A lot of people who are on the fringe of the industry, or are not in the industry,” explains Mike, “don’t think of Cessna Aviation, or Textron Aviation, as a real leader in aircraft interiors, when in fact we are.”
The secret is, Textron actually owns the manufacturing facility that makes its cabin materials, from furniture to side ledges to cabinets. Says Mike, “This way we can really control our quality and designs.”
XOJET’s custom-made Citation Xs are configured in the double-club setup, featuring bespoke seats with premium leather made by Townsend Leather. The carpet is hand-tufted by designers at PWV Carpets, while the sidewall contains custom embossed, wave-patterned leather, with a subtle metallic hand-tipped finish. The pièce de résistance? Beautifully polished wood veneers, ranging from light Birdseye Maples and Figured Anigre to the dark espresso tones of Eucalyptus or Zebrano, stained to reflect the look of Ebony.
“The challenge is, how do you make something both comfortable and stylish while aligning with FAA certification criteria?” says Mike, implying that interior parts often have to be made heavy or uncomfortable to meet safety standards. “That’s one of the things we do really well—creating a product or component that looks good, works well, is comfortable, and, oh by the way, passes these pretty stringent interior certification processes.”
When you add it all together—interior luxury and exterior innovation—the Citation X offers one of the most complete jet solutions ever known to general aviation. And while it’s admittedly easy on the eyes, it’s even better to fly.
“I’ve personally flown the airplane up to 48,000 feet and it flies beautifully,” says Mike. “It’s really quiet, the sky gets really dark blue, and the fuel flows really decrease.”
“I’d do it again this afternoon if they’d let me.”