An Audience with the Sovereign

Cleared for takeoff from Runway 34 at Westchester County Airport in White Plains, N.Y., I pushed on the Cessna Sovereign’s thrust levers, and to my surprise they surged forward out of my hand and into the takeoff thrust position. The aircraft seemed to want to fly, and I was quickly discovering that there was something different about Cessna’s updated midsize jet. Featuring more fuel efficient Pratt & Whitney Canada PW306D turbofan engines, winglets, a new cabin management system, and the innovative Garmin G5000 integrated avionics system, this was indeed a capable new Sovereign. 

The Sovereign has been in service since 2004, replacing the Citation VII in the Cessna lineup, and it has been a popular seller owing to the versatile combination of ample range, generous cabin volume and excellent field performance. Cessna’s intention to update it was announced at the National Business Aviation Association (NBAA) convention in October 2012, and the first flight occurred on April 30, 2013. Cessna calls the updated version the Citation Sovereign+. 

Skies was invited to test fly the updated Citation Sovereign on a crystal clear but blustery day last November. Cessna demonstration pilot, Gene Kenneford, gave me the guided tour. The demonstrator jet, N504SV, was still marked “experimental,” although FAA certification was subsequently received in December 2013. The jet had a basic empty weight of 18,300 pounds, featuring an opulent nine passenger interior, optional dual oxygen bottles, and high-frequency radio, in a configuration typical of a production corporate jet. Adding three humans and 5,800 pounds of fuel brought the takeoff weight to 24,707 pounds; well below the maximum takeoff weight of 30,775 pounds.

Kenneford led the pre-flight inspection, emphasizing that simplicity is a hallmark of the Sovereign design. The fuselage combines a Citation VII fuselage cross-section with a Citation X nose. It is an all-DC aircraft with a split-bus electrical system. The auxiliary power unit (APU) can heat or cool the aircraft on the ground. A closed-centre 3000 psi hydraulic system operates the landing gear, thrust reversers, brakes, nosewheel steering and spoilers. The Fowler flaps are electric, incorporating a flap-trim interconnect. The updated Sovereign also features mechanical reversible flight controls augmented by five fly-by-wire multi-function spoileron panels per wing. The ailerons employ variable gearing designed to tailor control forces to airspeed, although Kenneford warned that the mechanical controls give the Sovereign a decidedly heavy control feel. External highlights included the all-LED lighting, the spacious and easily accessible heated aft cargo compartment, and the snazzy new winglets. The wet wings can hold up to 11,390 pounds of usable fuel. 

At the top of the stairs, I momentarily mistook myself for someone important and turned right, into the Sovereign’s luxurious 5 foot, 8 inch tall interior.  The cabin can accommodate eight to 12 passenger seats, although the typical is a nine-place arrangement plus a spacious aft lavatory. Cessna craftily canted the seats inboard four degrees to make better use of interior volume. The new Clarity cabin management system employs a fibre-optic backbone with wireless connectivity, and will feature prominently in Cessna’s product line. The system employs touch pad consoles to control lights, temperature, electric window shades, music, videos, and even to send text messages between seats. The combined baggage capacity was an impressive 1,415 pounds in three compartments totaling 135 cubic feet. 

My first impression upon climbing into the cockpit was that it was almost Spartan in its simplicity. There were simply not enough fancy knobs and switches for a jet of the Sovereign’s complexity. I would shortly discover that this apparent simplicity was facilitated by the sophistication of the G5000 avionics. The cockpit was well designed; snug, but comfortable. 

As we taxied away, Kenneford advised me not to worry about riding the carbon brakes, as it would serve to warm them up and make them more effective. It was hardly necessary. Idle thrust was pleasantly low. I found the brakes and nosewheel steering smooth and precise. The pre-flight checks were simple—highlights being the thrust reversers, speedbrakes, flight controls and the rudder bias system—and we were quickly ready to fly.  

The G5000’s autothrottles bring a wealth of capabilities to the Sovereign, and literally reduced my workload even before I released the brake on takeoff. They are armed using a pushbutton on the back of the thrust levers, whereupon the “TO” icon appears on the top of the primary flight display (PFD), indicating that the next programmed power level is takeoff thrust. Having briefed a static thrust takeoff, I set the brakes and began to stand up the throttles. As they passed through 75 per cent N1, the thrust levers advanced automatically to the takeoff position, and thanks to the engine’s full-authority digital engine controls (FADEC), takeoff thrust stabilized precisely. Away we went. By programming the climb profile into the avionics, the autothrottles seemed to know what to do next. Climbing through 400 feet, the autothrottles reduced power to capture the programmed climb schedule. They also provide high- and low-airspeed protection and will automatically reduce power to respect the airspeed limit of 250 knots below 10,000 feet. I watched those throttles in chimp-like fascination throughout the flight, and their response was consistently smooth and precise. This was Garmin’s first autothrottle design and they just nailed it.  

My carefully planned flight profile unraveled immediately after takeoff. Somehow, the wrong flight plan was entered into ATC’s computers, and New York Center cleared us outbound toward Wichita, Kan. Unfortunately, we had planned a local test flight. 

We eventually negotiated some airspace with Center, and were cleared to 45,000 feet (FL450) for a cruise performance check. We levelled off with the power set at climb thrust and began to let the speed stabilize. After five minutes, the auto throttles reduced to maximum continuous thrust (MCT). At ISA -3C conditions, we saw 0.758 Mach, or 434 knots true airspeed (KTAS), burning a perfectly FADEC-matched 660 pounds per hour, per engine. Higher speeds are possible at lower, and consequently fuel-thirstier, altitudes. The advertised maximum cruise speed is 458 KTAS at 35,000 feet. At our cruising altitude, we observed a comfortable cabin altitude of 6,800 feet, with a 9.3 psi pressure differential. Cessna advertises that operating at its ceiling of FL470 the Sovereign has a range of 3,000 nautical miles. With full fuel, the demonstrator would retain a respectable 1,127 pound payload.

Cruising at 0.758 Mach doesn’t make the Sovereign the fastest jet in the stable, but Cessna knows its market. The Sovereign simply obeys the laws of physics, and the same design factors that increase a jet’s top speed are likely to increase a jet’s approach speed, at the expense of field performance. The ability to operate from a 3,650-foot runway at sea level standard conditions and maximum gross weight, as Cessna claims, will open up destinations. Cessna’s logic seems to be that with more airports available, the Sovereign can more often serve as the fastest means to get from where you are to where you want to go – even at a modest 0.758 Mach cruising speed. 

Notwithstanding all of the other improvements to the Sovereign, I was most excited by the new Garmin avionics. The three 1280 x 800 pixel resolution, 14.1-inch diagonal displays were bright, colourful and compelling. The left and right displays are typical PFDs, with insets for traffic and caution/advisory messages. They incorporated an edge-to-edge horizon line, heading graduations, and flight path vector. The central display was segmented to depict navigational and systems data, although the formats are easily reconfigurable. It was large enough to even add an approach plate or airfield diagram without appearing cramped. The system included synthetic vision, which depicted terrain, obstacles and traffic in a pseudo-perspective view on the PFD. I was at first dismissive of this “cartoon view” but quickly became a believer. Even when cruising at altitude, the effect of the terrain imagery sliding beneath the flight instrument symbology was to enhance situational awareness. I felt more in tune with the local geography, and in the event of an emergency descent it provided a natural sense for where high terrain lurked. My impression was that the synthetic vision made the primary flight display feel more like a window and less like an instrument. In fact, at one point New York Center interrupted our climb due to crossing traffic, which they identified as a Dash 8 at our eleven o’clock position at five miles. I was bemused to note that my gaze went straight to the PFD, where I saw the data from the traffic collision avoidance system (TCAS) overlaid just left of the nose and directly above a prominent terrain feature. It was only then that I looked out the window. Voila! There it was.

The neatest innovation in the Sovereign cockpit is the Garmin Touch Control screens, called GTCs. Each pilot is furnished with two: one just left of his left knee, and the other to the right of his right knee. They utilize infrared sensors to help discriminate between deliberate fingertip inputs and accidental contact. I found them fast, predictable and reliable. Think of them as the “everything controllers.” They are used to tune radios, adjust interior temperature, adjust the climb profile or a myriad other functions. They replace many of the knobs and switches in the cockpit, including the traditional flight management system (FMS) alphanumeric keyboards; and to admit my bias, I hate FMS keyboards! Perhaps this feeling arises from the fact that I have had exposure to many different models of FMS without ever having mastered any of them. Notwithstanding their ubiquity, flying an airplane using an FMS keyboard has always seemed as awkward as playing a banjo wearing mittens. Garmin has broken with the alpha-numeric state of the art in favour of a graphical interface with context-sensitive pop-up touch sensitive icons. Does that sound familiar? I couldn’t help but immediately think of my trusty iPad, and felt confident that with time I would develop a similarly cheerful opinion of the interface. 

Notwithstanding the G5000’s impressive capabilities, there was evidence of a touch of haste in getting the product to market. At the time of our test flight, the system featured neither computer-based performance calculations nor electronic checklists.

The acid test of the avionics’ usability arose when ATC gave us a descent clearance to proceed directly to an unknown airway intersection. “I’ve got it,” I proclaimed confidently, gesturing Kenneford’s fingers away from the panel, but keeping my doubts to myself. I touched the FLT PLAN icon and a new screen popped up. I touched a software button labelled DIRECT. More stuff popped up. By proceeding to do what seemed reasonable, I managed to convince the Sovereign to turn onto its new course. Space permitting, I would have stood up to take a bow. I have never successfully performed improvisation on an FMS keyboard. 

We flew a visual ILS to Runway 34 in Westchester County. The G5000 made the task of flying the approach almost trivial: simply lay the flight path marker on the synthetic vision runway threshold, and occasionally cross-check the ILS displays. The auto throttles managed airspeed and retarded the power to idle at 50 feet above the runway, leaving me nothing to do but flare. 

Among its many attributes, the single most impressive feature in the updated Sovereign is the Garmin G5000 avionics system. The G5000 made a terrific first impression. While perhaps not revolutionary, it certainly marks an evolution toward the airplane as an “app” with an interface that is so well designed that it is almost familiar upon first exposure. As a consequence, the cockpit became simpler by being simultaneously smarter. In retrospect, “smarter” might be an excellent way to describe the updated Sovereign. It’s now an even more desirable aircraft, and that was clearly Cessna’s intention.