Analysis

Could the Citation Ultra be related tothe "Sensible Citation" Cessna intro­duced 26 years ago? There's a strongfamily resemblance, especially in thenose, un-swept wings and cruciformtail. The fuselage cross section is thesame. Pratt & Whitney Canada JT15Dturbofans still provide the thrust. Asalways, the short landing gear seem tomake it hug the ramp.

In reality, the Ultra has about asmuch in common with the originalCitation 500 as a racehorse does with afarm horse. But that doesn't meanthat the Ultra has lost the Citation

500's everyday utility. It still offersbetter short-field performance thanvirtually any other turbofan aircraftwith the same number of seats. Itsslow-speed handling traits probablyare as forgivingas those of any currentproduction airplane with two engines.But that's where the similarity endsbetween the Ultra and its early ances­tor. For this year, Cessna is addingavionics features that further enhancethe Ultra's capabilities. (See avionicssidebar.)

This straight wing Citation is a per­former. The Ultra, loaded to maxi-

mum takeoff weight, can depart froma 3,200-foot runway, climb to FL 410in 23 minutes and fly more than 1,400nm at 400-plus knots. Slow down to370 KTAS, and it will fly between vir­tually any two points in the UnitedStates with one fuel stop-against themost probable headwinds.

Speed, range and short field perfor­mance help to explain why one out ofevery five new turbofan aircraft soldduring the last five years has been aCitation Ultra or its predecessor, theCitation V, according to Cessna's busi­ness jet sales tallies.

50 Business& Commercial Aviation. January 1997

Ultra's 17.4-foot-long cabin provides ample room for double club seats or, as shownhere, a center club with three to four additional seats at the ends of the cabin.

less, the Ultra will arrive within 10minutes or less of the Lemjet 31A.

STRUCTURE AND SYSTEMSIn spite of the Ultra's impressive per­formance, it remains true to Cessna'sgoal of building a simple turbofanbusiness airplane with straightforwardsystems.

Aluminum is the primary structuralmaterial used in the airframe. Com­posites are used for some secondarystructures, such as the ailerons andwing flaps. The fuselage has the famil­iar Citation circular cross section, andthe wing structure uses a classic, rigidtorque box formed by main and rearspars, ribs, skins and stiffeners.

The vault-design, forward entrydoor measures 50.7inches high by amaximum 23.5 inch­es wide near thebottom. A foldingladder, hinged at thedoor sill, is used forpassenger board­ing. Cessna alsooffers an optional35-inch wide, two­piece clamshell doorfor specialmissions.

On the right sideof the fuselage,directly across fromthe entry door, is anFAA Type III plug­design emergencyexit.

Systems simplicityis one of the Ultra's strongesLsellingpoints. The fuel system has left andright wing tanks that feed the left andright engines. Each wing tank is refu­eled through an over-wing filler port.As there are no fuel heaters, an anti­icing additive is required for fuels thatare not pre-mixed.

Electrically driven fuel-boost pumpsare used for engine starting, cross-feedand to back up the jet pumps duringabnormal operations.

A 24-volt, 40-amp/hour NiCd batterysupplies electric power for enginestarting and emergencies. Each enginehas a 300-amp starter-generator. DCelectrical power is used for most elec­trical and avionics functions, exceptfor vertical, directional and yaw rategyros, which depend upon AC power.An emergency battery supplies powerto the pilot's-side directional gyro, thestandby attitude indicator and RSI,

a maximum cruise speed of 0.73 to0.75 Mach-equivalent to about 420to 430 knots, depending on cruisealtitude.

The wing also features a cuffed,tapered inboard section with a longerchord adjacent to the fuselage. Thiseffectively reduces the thickness-to­chord ratio at the wing root, therebyresulting in an even milder pressuredistribution where the wing joins thefuselage. This design feature reduceswing-to-fuselageinterference drag.

Cessna equipped the modified high­speed wing with four-section Fowlerflaps that actually reduce V-speeds upto 10 knots compared to the CitationII's wing that is fitted with two-sectionhinged flaps. As an agded bonus, the

new wing's greater internal volumeholds about 800 pounds more fuel.

The new wing first went into pro­duction on the Citation SII in 1984.The thrust output of its engines,though, limited its maximum cruisespeed to just over 400 knots.

In 1988, the Citation V remediedthat shortcoming. Its JTI5D-5Aengines pushed maximum cruise speedup to 427 knots. The Ultra, introducedin 1994,just ups the ante. Its -5Dtur­bofans (see sidebar) enable it to climbfaster to cruise altitude and, thus,reduce block times on trips of alllengths.

The Ultra almost, but not quite,closes the performance lead of theclass-leading Learjet 31A, which isthe quickest airplane in the light­jet class, according to B/CA's 1996Planning & Purchasing Handbook.For example, on trips of 1,000 nm or

NON-TRADITIONALPERFORMANCE

The Ultra, being the fastest straight­wing Citation yet produced, is close to90 knots faster than the Citation 500that made its debut in 1969. It takes aclose look, however, to see how Cessnaaccomplished this considerable leap inperformance.

The original Citation 500, I and IIwere fitted with NACA 23000-seriesairfoils, not unlike those used onRaytheon King Airs. The time-proven23000-series airfoils have relativelybenign stall characteristics, but com­pressibility drag rises sharply abovecruising speeds of 0.65 to 0.67 Mach.At 0.70 Mach, the 23000-series airfoilruns into a virtual drag wall.

This wasn't aproblem in earlyCitations becausePratt & WhitneyCanada's first-gen­eration JT15D tur­bofans only pro­duced enough thrustto push them to 335to 375 knots. As aresult, the wing andthe engines actuallywere quite wellmatched.

As Pratt & Whit­ney developed high­er thrust versions ofthe JT15D engine,however, Cessnarecognized the need -------------------------------to develop a wingwith a higher cruise speed.

Fitting the Citation with a clean­sheet wing was out of the question.Cessna's customers would have balkedat the price increase. Instead, Cessna'saerodynamicist collaborated withNASA's Richard T. Whitcomb, fatherof the supercritical wing, to develop amodified wing that would use theexisting wing spars.

While not a true supercritical wing,the new airfoil incorporates a largerleading-edge radius and a relativelyflat upper surface. Airflowover the topof the wing is accelerated more mildlythan with the 23000-series wing, andlift is distributed over a longer chordsection. The result in less compress­ibility drag.

The tangible result for operators,claims Cessna's aerodynamicists, isa 0.08 Mach increase in maximumcruise speed. The modified wing has

ANALYSIS

ULTRA'S AVIONICS

Honeywell's Primus 1000forms the basis for the Ultra's avionicspackage.Three, eight-by-seven-inch CRT displays, made up of left- and right-sideprimary flight displays (PFDs) plus a multifunction display (MFD) in thecenter, occupythe panel. New to this year's model are the formerly option­al, now standard, equipment-Ieft- and right-side Primus II radio manage­ment units that flank the MFD-':"'indicatingthat Honeywell com/nav/identradios have become standard equipment. (Collins Pro Line II radios werestandard equipment in previous Ultra aircraft.)

Two Meggitt LCDs also are new to the Ultra's panel. The upper LCD isa standby EADI with air-data tapes, and the lower is a standby EHS!.These solid-state systems replace the electromechanical standby instru­ments that were used in older 560s.

The console now houses an AlliedSignal GNS-XL one-box FMS with aGPS approach capability, in place of the GNS-XES that lacked a TSOC129 GPS sensor. Ultra customers also can choose a Universal AvionicsUNS-1Csp (a box that was certificated on the Ultra in mid 1996)as a stan­dard option. The Primus 1000 EFIS software has been upgraded to pro­vide for the automatic course deviation needle scaling required for GPSnon-precision approaches.

Both the AlliedSignal and Universal FMSes offer a GPS non-precisionapproach capability, but the UNS-1Csp has more performance features,such as full SID/STARguidance, all ARINC 424 procedure legs, multiplewaypoint vertical navigation and coupled vertical path navigation on non­precision approaches.

Other standard avionics include the Primus 1000 digital flight-guidancesystem, dual Honeywell mechanical and vertical gyros, dual digital air­data systems, dual Primus II radio audio-control panels with digital audiobuses, a Primus 650 weather radar and an AA 300 radio altimeter. ALoral/Fairchild CVRand an Artex ELTllO-4 also are included in the stan­dard package. Avionics options include AlliedSignal Global WulfsbergAFIS, an HF transceiver, Coltech Selcal, AlliedSignal TCAS I, II andGPWS, and a Fairchild FDR.

Cabin options include a Hughes MagnaStar or AlliedSignal GlobalWulfsberg Flitefone air-to-ground radiotelephone, an Airshow 400 cabinentertainment and real-time information system, and other airborne officeequipment.

52 p,,,.in •••• & Commercial Aviatian • January 1997

N1 fan speed tachometers, the com 1and nav 2 radios, standby pitot andstatic heaters, both audio panels andthe overhead floodlights.

Each wingtip has a landing light anda recognition light, plus each mainlanding gear strut has a taxi light.Logolights illuminate the vertical fin.

The -5D engines produce enoughsurplus bleed air for cabin pressuriza­tion and air conditioning, plus engineinlet, inboard wing leading edge andwindshield anti-ice. In contrast, Cita­tions 500, I and II, lacking such bleedair output, used electrical heating ele­ments for inboard wing leading edgeanti-ice. The heating elements, nick­named "waffle irons," occasionallymalfunction, and they require 400­amp starter-generators.

Conformal deice boots, inflatedby low-pressure bleed air, protectthe outboard wing and horizontalstabilizer leading edges against iceaccumulation.

There is no APD. However, the rightengine has a unique bleed-air groundfeature. When selected, this triples theair flow from the right engine for heat­ing or air conditioning, therebyimproving temperature control. Ahigh-capacity, electrically powered,vapor-cycle air conditioner, which hasboth front and rear evaporators, aug­ments the air-cycle machine for cool­ing. The vapor-cycle air conditioner,which can be powered by a 28-voltGPU, can be used in flight up to

GNS-XL or UNS-' C FMSes, now fullyintegrated with the avionics suite, give theUltra a GPS non-precision approachcapability.

P&WC JTlSD·SD

Twenty-five years ago, Pratt & Whitney Canada achieved certification onthe first of a new family of JT15D light turbofan engines that has becomeone of the most reliable turbine powerplants ever designed.

The original -1 engine is a study in simplicity. The gas generator coreconsists of a single centrifugal flow compressor, combustor and singlehigh-pressure turbine. Most of the exhaust energy is absorbed by a two­stage, low-pressure turbin.e that, by means of a concentric shaft, powers asimple bladed fan in the front of the engine. Because the fan producesmost of the thrust, the bypass ratio is 3.3:1.

A relatively low overall pressure ratio, no flat-rating and the relativelyhigh bypass ratio result in a comparatively high thrust-lapse rate for the-1 engines. They lose more than 80 percent of their takeoff thrust at high­altitude cruise.

P&WC started to remedy that shortcoming with the -4 engines. Theyare fitted with an additional low-pressure turbine stage and a single, axial­flow supercharger compressor on the Nl shaft aft of the fan.

This boosts the overall pressure ratio, but it also reduces the bypassratio to 3:1. The result is slightly higher specific fuel consumption, butmore high-altitude thrust. Internally, the -5 engines are similar to the -4engines, but they also have the following features: a wide-chord fan, amore robust core, improvement in high-pressure compressor aerodynam­ics, a fine-tuned exhaust nozzle and a higher overall pressure ratio. Theseengines retain almost 25 percent of their thrust at high altitude. Notably,the -5 engines have the lowest bypass ratios in the JT15D family, but theyalso have the best thrust-specific fuel consumption at high altitudebecause of their higher pressure ratios.

The -5D is the most highly evolved of the -5 series, a 3,350-pound ther­modynamic rated turbofan that is flat-rated at 3,045 pounds of thrust fortakeoff to 27°C (80°F).The -5Duses integral blade rotors, machined froma single piece of metal, for the fan and axial supercharger compressor, plusit is fitted with high-temperature tolerant, single-crystal high-pressureturbine blades.

With the widest chord design in the -5 family, the fan is shrouded by aKevlar belt for better sealing and lower weight. The result is five percentmore thrust than the Citation V's -5Aengines produce and a one-percentimprovement in specificfuel consumption at high-altitude cruise. At 0.80Mach, 40,000 feet (uninstalled), the -5D engine produces 737 pounds ofthrust with a 0.868 lbllb tsfc. (That's almost 98 percent of the high-alti­tude thrust output of the AlliedSignal TFE731-2 that powers 30-seriesLearjets.)

Having a 2.1:1 bypass ratio has one unwanted side effect: The Ultra isone of the noisiest straight-wing Citations for airport neighbors. But thatfact must be put into perspective; it still is one of the quietest turbofan air­craft on takeoff, especially when you are flying a noise-abatement depar­ture profile. Cessna claims the Ultra can whisper over the airportneighbors at 67.1 dBA if the thrust is pulled back to 80.2 percent Nl dur­ing the initial climb.

18,000 feet msl. There is a single-zonethermostat, but the air flow betweenthe cockpit and the cabin can be variedto produce a comfortable temperaturein each location.

The hydraulic system is an on­demand, open-center design in whichengine-driven hydraulic pumps contin­uously circulate fluid at low pressure,thereby minimizing the potential forleaks. When hydraulic pressure isneeded to power the landing gear,wing flaps, spoilers or reversers, abypass valve in the return line closes,causing the pressure to increase to1,500 psi. As soon as the desired actionis complete, the bypass valve opensand the system returns to low pres­sure operation.

A separate electrically drivenhydraulic pump charges the anti-skid,power brake accumulator. An emer­gency pneumatic brake system pro­vides a back-up for the hydraulicpower brakes.

The primary flight controls are man­ually operated with console-mountedtrim wheels for all three axes. Theelectric pitch-trim system can be oper­ated by a conventional split switch onthe pilot's yoke.

Nosewheel steering is connected tothe rudder pedals by means of springlinks that provide +/-20 degrees ofsteering authority. Differential powerand braking can be used for tighterturns.

The flaps have four detents: retract­ed, seven degrees (takeotl), 15 degrees(takeoff and approach) and 35 degrees(landing). The electrically controlledand hydraulically powered speedbrakes have two positions-retractedor extended.

About five to 10 percent of Cessna'scustomers order the optional gravelrunway kit. This option features anose-wheel spin-up system that pre­vents debris from being kicked up intothe engines when the nosewheeltouches down on the runway, alongwith antenna guards and flap shields.

PASSENGER AMENITIESThe Ultra has the longest cabin of anystraight-wing Citation yet produced.

The cabin is 1.5 feet longer than thecabin of a Bravo and a full four feetlonger than the original Citation 500.

A five-inch dropped aisle, whichextends from just aft of the cockpitthroughout most of the seating area,increases headroom to 55.3 inches.

The extra length allows the cabin tobe configured in double club, withenough room left over for a full-width,aft lavatory. Pyramid cabinets in thecenter cabin, between the two clubsections, provide most of the onboardstorage for small stores.

However, at least half of the Ultras,including the demonstrator we flewfor this report, are configured with acenter club section, with three to four

other seats facing into the club. Thisconfiguration permits the aft clubseats to be mounted on seat tracksthat allow them to be moved back anadditional seven inches for greaterlegroomin the center club section.

The center club is flanked by a for­ward refreshment center on the leftand an aft-facing chair adjacent to theright-front cabin bulkhead. Two for­ward-facing chairs are placed behind

Business& Commercial Aviation. Januarv 1997 53

Just aft of the cockpit, the refreshment center accommodates hot and cold beverages, agenerous amount of ice and catering trays in 16-inch-wide drawers.

the club section and ahead of the lava­tory bulkhead.

In our opinion, the interior quality istop notch. It's in keeping with theUltra's $6-million price tag and thebest we've seen in a 500-series Cita­tion. The overhead and sidewalls arecovered in seamless sheets of fabric,and indirect lighting makes the cabinseem larger than its measurementsreveal.

The side rails, finished with woodlaminates or optional veneers, havecup holders for each seat. The lowercabin sidewalls are covered in durable,embossed leather or a choice of otherlong-wearing fabrics. The wool carpethas a strong silk backing and isfireblocked.

Aircraft Modular Products of Miamibuilds the passenger chairs, whichCessna covers in a choice of leathers.They are equipped with lap and shoul­der belts, they are adjustable in pitch,rake and track, and they have re­tractable headrests. They also swivelon their pedestals and contain smallstorage drawers in the pedestal bases.

Precision Pattern in Wichita buildsthe cabinetry, also first rate, whichrepresents a radical improvement overthe furnishings of early Citations. Therefreshment center, for example, ismade of strong, durable and light­weight hollow core composites coveredwith a choice of high-gloss-finishedwood laminates. Wood veneers andinlays are available as extra costoptions.

Inside the refreshment center is hot-

ANALYSIS

A full-width aft lav features sturdyprivacy doors and an optional sink withrunning water. The toilet, though, isinternally serviced.

and cold-beverage storage, a relativelylarge, stainless-steel ice bin, rollingracks for canned beverages, space tostore miniatures, and a 16-inch-widerollout drawer that holds small cater­ing trays. It also has a generouslysized, leakproof, stainless-steel wastecontainer located in a deep pull-outdrawer.

The aft lavatory's toilet has a remov­able waste container. An externallyserviced lavatory is not available.Access to the lavatory is a little diffi­cult, in our opinion, because the mainwing spar transverses the aft cabin,more than seven inches above the

floor level and a full foot above thedropped aisle. There is less than 49inches of headroom in most of thelavatory, except for a small foot well.

Cabin options include upgradedwoods and leathers, additional cabi­nets for magazines and small stores,and a lavatory vanity cabinet witha sink providing fresh water. An Air­show cabin entertainment systemwith individual, full-color, flat-panelvideo screens and audio jacks is alsoan option.

The Ultra retains the straight-wingCitation's unique, nose external lug­gage compartment, which is carriedover from its propeller-driven twins. Itis ideal for briefcase missions becauseof its shallow floor, 15 cubic feet of vol­ume, and accessibilityby means of leftand right baggage compartment doors.

A separate 28-cubic-footaft externalcompartment holds 500 pounds of lug­gage. Inside the cabin, on the left sideof the lavatory, is an additional 26cubic feet of baggage volume that willhold 600 pounds.

FLYING IMPRESSIONSThe Ultra is one of those aircraftwith which one immediately becomescomfortable. Once you've masteredthe FMS, you're probably 90 percentassured of a successful checkride. Onthis flight, I was accompanied byCessna Citation demonstration pilotTerry Lee.

Preflight chores reflect the design ofthe systems: simple and straightfor­ward. Everything is within easy reach,but the Ultra's low stance makes it alittle tough to get to the fuel drainsand brake-wear indicators.

Starting an engine is easy. Turn onthe battery and AC power switches,touch an engine-start button and waitfor the N2 turbine rpm gauge to readeight to 10 percent. At that point, justadvance the thrust lever into the idledetent, and normally all other startfunctions, including the starter-to-gen­erator transition, are automatic. (Ifyou want to preheat or pre-cool thecabin, you may want to start the rightengine first to take advantage of thetriple-bleed-air flow rate of the bleedair ground feature.)

Citations use a generator-assistedcross start to help start the secondengine when using battery power.Bump up the operating engine to pre­cisely 52 percent N2 turbine rpm, andyou'll be assured that it supplies just

54 Busin"" & Comm"rc:inl Av;ntion • jnnuorv 1997

the right amount of supplemental elec­trical current, Use more than 53 per­cent, though, and you can damage thegenerator drive,

In the Ultra, however, no longer dopilots have to fine-tune the high-speedidle for cross start, Flick the ground

idle switch from normal to high, andthe N2 rpm increases to exactly therequired speed.

Our computed takeoff was a svelte13,800 pounds-2,500 pounds belowMTOW, Computing V-speeds andtakeoff field lengths is a snap in Cita-

tions. Cessna publishes all the data intables, so there are no cumbersomecharts to plot and no fat-finger errors,The takeoff V-speedswere 86 KIASforthe Vi takeoff decision speed, 94 KIASfor rotation and 106 KIAS for the V2one engine inoperative (OEI) takeoff

TIME AND FUEL VERSUS DISTANCE SPECIFIC RANGE

450

1,800

400

4

1,500

4,147

1,200

350

Speed (KTAS)

3

3,039

300

900Range (nm)

2

2,099

600

0.20

250

0.45

0.40

0.25

JO

"­E

.=. 0.35'"lllIcl'O

D::

.g 0.30'u'"Q,l/l

5

1

1,174

300

RANGE/PAYLOAD PROFILE

Conditions: 800-lb(four-pax)payload; 100-nmalternate + 45-min. reserves;zero wind; ISA

2 34Time (hrs)

FuelIBurn

Gross(Ibs)

TakeoffTime

Weight (Ibs)(hrs)

r-:::-;16,300 16,000

15,00014,00013,00012,00011,00010,000

01

380nm~

1,4261bs //

\ ~ 350 nm~ 1,174Ibs

oo

300

900

600

Balanced Field Length (ft)

SL

5,000 ftISA

ISA+20°C

3,350

4,7303,070

4,550

2,740

4,000

2,600

3,500

2,570

3,050

2,560

2,650

--High-Speed Cruise

1,500 +-1- Long-Range Cruise

1,800

1,200

Ec'"uc.l!l'"Q

CESSNA CITATION ULTRA

These three graphs are designed to be usedtogether to provide a broad view of Citation Ultraperformance_ Do not use these data for flightplanning. For a complete operational performance

analysis, consult the Citation Ultra airplane flightmanual and appropriate cruise performance datasupplied by Cessna Aircraft.

Time and Fuel Versus Distance-This graphshows the performance of the Citation Ultra atlong-range cruise and high-speed cruise_ Thenumbers at the hour lines indicate cumulativemiles and fuel burned for each of the two cruise

profiles. The intermediate pOints are approximat-

ed from climb, cruise and descent data published

in the Citation Ultra fiight planning guide. Ourexperience flying the Ultra suggests that Cess­na's published cruise performance numbers areconservative.

Specific Range-The specific range of the Cita­tion Ultra, the ratio of nautical miles flown to

pounds of fuel burned (nm/lb), is a measure ofits fuel efficiency, This graph shows long-rangecruise and high-speed cruise specific range val­ues throughout the typical cruise altitude enve­lope of the Citation Ultra. Notably, the fuel

efficiency of the Ultra drops off markedly at high­speed cruise, as shown by the steep slope of thespecific range lines at each cruise altitude. The

relatively narrow spread between maximum-rangeand high-speed cruise specific-range values at thetop of the envelope indicates that both speedand fuel economy are optimized when cruisingabove FL 410.

Range/Payload Profile-The purpose of thisgraph is to provide rough simulations of tripsunder a variety of payload and airport density alti­tude conditions, with the goal of flying the longestdistance at long-range cruise. The payload lines,which are intended for gross simulation purposesonly, are valid only for the endpoints_ The timeand fuel burns shown at the top of the chart areplotted for four-passenger (800-pound payload)missions.

ANALYSIS

Tradeoffs are a reality of aircraft design, although aeronautical engineers attempt to give each modelexceptional capabilities in all areas at an affordabie price. The laws of physics, however, do not allowone aircraft model to do all missions with equal efficiency.

In order to obtain a feeling for the strengths and compromises of a particular aircraft, B/CA com­pares the subject aircraft's performance to the composite characteristics of the aircraft in its class.We average parameters of interest for the aircraft that are most likely to be considered as competi­tive with the subject of our analysis, and then compute the percentage differences between theparameters of the subject aircraft and the composite numbers of the competitive group as a whole.Those differences are presented in bar-graph form. We also include the absolute value of the parame­ter under consideration, along with its rank with respect to the composite.

For this Comparison Profile®, we present select parameters of the Cessna Citation Ultra in rela­tion to a composite group consisting of the CitationJet, the Learjet 31A and the Raytheon Beechjet400A. The Comparison Profile® is meant to illustrate the relative strengths and compromises of thesubject aircraft; it is not a means of comparing specific aircraft to each other.

result of the modified wing design, isnot as gentle as in early Citations fit­ted with the 23000-series airfoils. Astick shaker warns of the impendingstall, and the actual stall break isaccompanied by noteworthy wingdrop. When pressed beyond the initialstall break, the Ultra may exhibit apronounced wing rock. However, ifstall recovery is initiated at the firstsign of stall buffet, there is little alti­tude loss and no loss of directional orroll control.

The four, large, trailing-edge, Fowler

safety speed. The computed takeofffield length was 2,680 feet. (If we haddeparted at MTOW, the takeoff dis­tance would have been 3,560 feet, andV2would have been 112 KIAS.)

Once cleared for takeoff on Wichita'sRunway 19R, I advanced the thrustlevers, which Lee adjusted to 97.3 per­cent Nl. The Ultra responded likeCitation, sprinting out of the startinggate.

"Airspeed's alive cross check, Vl,rotate, V2, positive rate," Leeannounced almost in a continuousstream.

The pitch force at rotation was mod­erate. Our initial fuel flow on takeoffwas 3,600 pph, and the initial climbrate was in excess of 5,000 fpm as weaccelerated to the 200 KIAS Class Dairspace speed limit.

Once clear, we made the transitionto a 250 KIAS/0.62 IMN climb sched­ule. Our fuel flow through 5,000 feetwas 2,800 pph. The thrust levers haveto be adjusted frequently during theclimb because the hydromechanicalfuel controls lack digital computersophistication. In a scant 20 minutes,we reached FL 410, and we were stillclimbing at 1,000 fpm as we began thelevel-offat cruise altitude.

We set 98.1 percent Nl for high­speed cruise, making no effort to con­serve fuel, which resulted in a fuel 8flow of 1,190 pph. The aircraft stabi- 1lized at 0.752 Mach-only 0.003 below iredline. Our true airspeed was 433 .~knots, 14 knots faster than the book ~value for our weight and fuel flow. At ci:

lower weights, the Ultra will push g,through MMOat maximum cruise .§

thrust, according to Lee. £A quick check of the yaw stability ~

revealed that, because of its additional ~thrust, the Ultra is more mildly ~damped in yaw than earlier straight- ~wing Citations. Passengers will appre- ~ciate use of the yaw damper, but it is </)

not required for dispatch.In contrast, the Ultra is well damped

in pitch and roll. On our descent fromFL 410 to 15,000 feet for air work, wefound that deploying the spoilers caus­es a mild nose-down pitching moment,resulting in an increase in airspeed.However, a combination of landinggear (VLOat 250 KIAS) and spoilerextension produces little nose-downpitching moment and descent rates inexcess of 9,000 fpm when needed foremergency descents.

The Ultra's stall behavior, as a

B/CA COMPARISON PROFILE®(% Relative to Average)30 ~ III...l.III. IIIIIICitation UltraIII

a;Price Index

> ex: 20III>0..Qex:

10

III

'Ol)III 0a; >ex:

-10

III'Ol)IIIa;>ex: -20==0GiIII

-30

flaps produce a strong nose-downpitching moment when deployed, butas a pilot, you'd never know it. Aflap/pitch trim interconnect compen­sator all but eliminates the pitchingmoment.

We headed for Hutchinson, Kansasfor instrument approaches and land­ing-pattern work. We set the speedbug at 100 KIAS for VREF,based on alanding weight of 13,000pounds.

Straight-wing Citations are not par­ticularly slippery, so slowing down inthe Ultra isn't a challenge. You can

maintain 250 KlAS until you are closeto the initial approach fix, and thenyou can use a combination of flaps,spoilers and landing gear to quicklydecelerate to the desired approachspeed.

We found that relatively low thrustsettings will maintain VREF speed onfinal, because the four-section flapsproduce plenty of lift and yet onlymoderate drag.

Over the threshold, we slowlypulledthe thrust levers to idle and flattenedthe approach attitude in anticipation

CITATION ULTRASPECIFICATIONS

B/CA Equipped Price $5.988.000

CharacteristicsWing Loading

47.6

Power Loading

2.68

Noise (EPNdB) Takeoff/Approach82.9/85.7

Seating

2 + 7/11

Dimensions (ft/m)ExternalLength

48.9/14.9Height

15.0/4.6Width

52.2/15.9Internal Length

17.4/5.3Height

4.8/1.5Width

4.9/1.5

Power Engine

2 P&WC JT15D·5D

Output3.045 Ibs ea.

1803.500 hrs

Weights (Ibs/kg)Max Ramp

16.500/7,484Max Takeoff

16.300/7.394Max Landing

15.200/6.895ZFW

12.200/5.534BOW

9.92514.502Max Payload

2.275/1.032Useful Load

6.575/2.982Executive Payload

1,4001635Max Fuel

5.771/2.618Payload-Max Fuel

804/365Fuel-Max Payload

4.300/1.950Fuel-Exec. Payload

5.175/2.347

LimitsMMo

0.755

FL/VMoFL 289/292

VFE(app.)

200PSI

8.9

Climb (fpm/mpm)All Engine

4.230/1.289Engi ne-Out Rate

1.185/361Engine-Out Gradient

450/85

Ceilings (ft/m)Certificated

45.000/13.716All-Engine Service

45.000/13.716Engine-Out Service

26.000/7 .925Sea-Level Cabin

23.586/7.189

Certification

FAR 25. 1971/94

of the landing plunk. The Ultra'sshort-travel, straight-leg oleos offervery little cushion at touchdown, andconsistently smooth landings requireplenty of practice.

Simulated OEI takeoffs and landingsaren't much of a challenge in theUltra. The large rudder and relativelylong fuselage offer excellent direction­al control, plus the engines are mount­ed close to the fuselage.' As a result,there is no need for a rudder boost orbias system.

Mter the pattern work, we returnedto Wichita for a final landing, accom­panied by another minor plunk attouchdown. Our total fuel burn for the1.7-hour flight was 2,200pounds.

PRICE AND VALUEThe Citation Ultra currently is themost expensive offering in the light-jetmarket, but that doesn't seem to beslowing its sales_ Our B/CA Compari­son Profile® may explain why. Ultra'scabin cross section is pretty muchstandard for the light-jet class, but itoffers eight passengers considerablymore length than its competitors do.

The Ultra offers strong range/pay­load performance in the light-jet class,as shown by the accompanyingRange/Payload Profile_ Only theRaytheon Beechjet 400A offers more

CITATION ULTRAOPERATING COSTS

Hourly Direct Costs:Fuel @ $2.00/Gallon $388.00Maintenance-Labor 69.60Maintenance-Parts 77.45

Engine Reserves 217.70Thrust Reverser Reserves* 10.00

Landing and Parking Fees* 10.00Miscellaneous Crew Expense* 125.00Small Supplies and Catering* 15.00

TOTAL $912.75

Annual Fixed Costs:

Captain $63.000Copilot .42 .000Benefits Package @25%* 28.750Hangar 12.000Insurance-Hull @ 0.3% 17.964Insurance-Liability and Medical 3.000Recurrent Training 17.250Aircraft Refurbishment* 25.000Navigation Chart Service 886Computerized MaintenanceProgram * 1.250Weather Services* 1.000Fair Market Depreciation @ 6%* 359.280

TOTAL $571,380

Source: Cessna Aircraft. Pratt & WhitneyCanada and *B/CA estimates

payload-and then by only 15 pounds.But the Ultra can carry its maximumpayload almost 250 miles farther thanthe Beechjet.

Runway performance is the Ultra'sstrongest performance asset. On1,000-mile trips, it has the shortesttakeoff field distance. When loaded tomaximum takeoff weight on a stan­dard day, the Ultra needs only 100 feetmore runway than the class-leadingCitationJet, an aircraft that offerscloseto one-third less range.

The Ultra's hot-and-high perfor­mance is clearly better than any otherlight jet's. Notably, when departinga 5,000-foot elevation airport, theUltra doesn't run into a second-seg­ment OEI climb limitation until theOAT reaches 33°C C91°F). This islargely due to the Ultra's relativelylow wing loading.

Need even more climb performance?You can opt to depart at flaps sevendegrees, instead of flaps 15 degrees.The takeoff field length increases to5,050 feet-still the best in class-andyou can depart at the full 16,300­pound MTOWat 40°C(104°F).

Most of the Ultra's below-averagemarks come from its relative fuel­thirstiness, as shown by some of the

bars on the ~ht side of the Compari­son Profile . This results from ablend of engine efficiency and aero­dynamics. The JT15D-5D burns six to12 percent more fuel than other turbo­fans in its thrust class.

The Ultra's wing aerodynamics, asindicated by its relatively low 0.755MMo, impose a tangible drag penaltyat high-speed cruise. In addition, theUltra has more frontal and surfacedrag than its competitors because ofits dimensions.

The Ultra, however, currently hasthe most cabin volume in the light-jetclass, along with a clear advantage inrunway performance and competitiveblock-to-block speed. Judging by theaircraft's sales success, light-jet buyersare lookingfor exactly those qualities.

Cessna's continuous-improvementprogram should assure the Ultra of along and successful production run.With the 400th unit coming off theproduction line early this year, theUltra, and its predecessor the CitationV, just might become Cessna's mostpopular Citation aircraft yet. -

By Fred George

Business & Commercial Aviation. January 1997 57