Guy Norris/WITCHITA
Cessna comes to the US National Business Aviation Association (NBAA) meeting this year with an unprecedented array of eight Citation models either in production, flight test or planning.
Filled with ambition, and keen to bolster the competitiveness of the Citation family against a new generation of business jets, Cessna is effectively doubling the size of its Citation product range in virtually one move. "This package is a whole new level for us," says Cessna chairman Russ Meyer.
Spearheading this aggressive new strategy is the Citation Sovereign - a new mid-size business jet designed to take on what Cessna sees as a large, generally unexploited, sector of the market. The company's research shows that, of almost 1,760 mid-size business jets in service, around 830 are early generation aircraft such as the Dassault Falcon 10, Israel Aircraft Industries Westwind and Rockwell Sabreliner. The bulk of the balance is made up of Bombardier Learjet 55/60s, Raytheon Hawker 800s and its own 650 series Citations.
Cessna believes therefore that the time is ripe for a new generation mid-size jet. The company also knows that it will not be alone in competing for this market, and that Bombardier is close behind with its own new mid-size business jet, designated internally as the BD100. The result is what Meyer describes as "the largest commitment to a new aircraft in Cessna's history".
Cessna's trump cards in the Sovereign design appear to be cabin space and price. The company looked hard at an all-new cross section, but, to keep costs under a tight rein and to reduce time to market, elected to stretch the existing Citation Excel instead. "We evaluated a wide cabin, but it quickly rose in price," confirms Cessna vice-chairman Gary Hay, who adds that "-we did go for a new wing and a new tail, but the systems are common to the Excel".
The "superlight" Excel was stretched by 1.5m to give an overall length of 18.9m and an enlarged cabin which has "-40% more volume than the Lear 60", says Sovereign product manager Brad Thress.
"No one has ever built an aircraft this big that will take you so far for so little money," says Thress, who adds that the fully equipped aircraft is expected to cost just under $12 million, including traffic alert and collision avoidance and enhanced ground proximity warning systems. A typically equipped Sovereign is expected to sell at $12.7 million.
The 19.2m-span wing is all new, with a mild, 16.1°, leading edge sweep (12.7° sweep at the quarter-chord position), and low drag characteristics for high-speed cruise. Although the 47.4m2 wing is not as distinctly aft-loaded as that of the Citation VII, it has a supercritical aerofoil section and blends aerodynamic and structural lessons from the 650 series, Citation V and Citation X. The design team has also given the Sovereign a low-drag fin for high operating cruise speeds of up to 445kt (820km/h) at 35,000ft (10,700m), or around Mach 0.75 at 45,000ft. The horizontal stabiliser is also given a slight sweep.
The Pratt & Whitney Canada PW306C engine, flat-rated at 5,690lb thrust (25.3kN) to 15°C, was selected after an "exhaustive" campaign, says Hay. The chief competitor was AlliedSignal, which offered the TFE731-60 and a derated version of the new AS900. Cessna's choice was based partly on the PW306's use on the Fairchild 328JET and the related maintenance spin-offs. "We're excited by the similar benefits we've seen with the [Rolls-Royce Allison] AE3007," says Thress, referring to the dual application of the engine on the Citation X and Embraer RJ-145 regional jet. Based on the more rigorous operating demands of the airline industry, P&WC is offering a 6,000h time between overhauls (TBO) "out of the box", and a 3,000h hot section inspection (HSI) interval. The engine has a 4.3:1 bypass ratio and is controlled by dual full authority digital engine controls.
Payload with full fuel will be 725kg. Cessna has listened to the market and extended the range with eight passengers to 4,600km (2,500nm - NBAA instrument flight rules reserves), or up to 5,300km with visual flight rules reserves. The certified ceiling will be a relatively lofty 47,000ft, and time to climb is expected to be a spritely 26min to 43,000ft, and 20min to 41,000ft at maximum take-off weight (MTOW). As with previous generations, Cessna has striven to retain the Citation's good field performance. Sea level take-off distance is an estimated 4,080ft (balanced field length) at MTOW and landing distance 3,200ft at maximum landing weight.
Cessna has chosen Honeywell's Epic CDS avionics for the Sovereign, which is designated the Model 680. The cockpit will feature four 200 x 250mm (8 x 10in) flat-panel displays, with engine instruments on a multifunction display and lighted indicating switches. The aircraft will also feature digital dual channel autopilot and flight director, dual long range navigation systems and dual attitude/heading reference systems, and will have reduced vertical separation minima (RVSM) group certification.
Cessna knows that its crucial decision to opt for an Excel-based derivative will only pay real dividends if it can beat any other newcomers to the mid-size market it has identified. The Sovereign is therefore due to emerge quickly, with the fast-paced development programme aiming at certification in the second quarter of 2002 and first deliveries beginning in the third quarter of that year.
ULTRA, ENCORE
With 278 sales under its belt Cessna justifiably describes the 560-series Citation V Ultra as the "best-selling business jet of the decade". Introduced in 1993, the first Ultra was delivered in June 1994 and, today, Cessna has an order backlog worth $235 million.
The Ultra was conceived as an improved Citation V light jet, and reaped the rewards of better performance and low price. To repeat this, and to propagate the success of the Ultra line into the next century, Cessna has elected to improve the aircraft yet again and has therefore dubbed it the Encore.
First flown in secrecy at Wichita on 9 July, the Encore incorporates a wide range of new features and enhancements. Perhaps the biggest single improvement is to the powerplant, which sees replacement of the 3,045lb-thrust P&WC JT15D-5D with the Canadian manufacturer's more advanced, more powerful, 3,360lb-thrust PW535A. With a 5,000h initial TBO, 2,500h HSI and a 15% lower specific fuel consumption than that of its predecessor, the operating costs of the engine and, therefore, the Encore are expected to be significantly lower. Despite moving to the more advanced engine, Cessna has retained the standard hydro-mechanical fuel controllers to maintain high dispatch reliability. The engine will also be fitted with a Nordam thrust reverser and a forced exhaust mixer to reduce noise.
The higher mass flow of the PW535A means that, for the first time, sufficient bleed air is available for leading edge anti-ice protection. The same feature is also being applied to the Sovereign. Mike Pierce, product manager for the Excel, Ultra Encore and Ultra, says that the new anti-ice system "-will reduce workload and make the leading edge a bit easier to care for". Another device to reduce pilot work is a new digital pressurisation system, with a single setting required before take-off.
Smoother landings, which even Cessna acknowledges are never an easy task with the current Ultra, will also be made possible with the introduction of trailing link main landing gear. "All Citations will be changing to the trailing link system," says Pierce, who adds that the change will also improve the aircraft's taxi ride and ground handling qualities. Although the span remains the same at 15.9m (52.2ft), the track of the main gear is being reduced by 1.8m to 4m to aid ground handling. A new braking system and master cylinder is also being added to reduce "grabbiness" during taxiing and ground runs.
The plumbing for the anti-ice system and changes to the wing spar to accommodate the revised gear effectively reduces maximum fuel payload from 2,640kg in the Ultra to 2,405kg in the Encore. Thanks to the higher efficiency of the new engines, however, the Encore will have a slightly longer range of 3,700km in visual flight rules (VFR) - 3,145km instrument flight rules - and a full-fuel payload of 450kg, compared to 335kg for the original Ultra. Largely because of the bigger engines, the empty weight rises by more than 230kg, to 4,780kg, while MTOW rises to 7,550kg, compared to 7,400kg for the Ultra.
Time to climb performance has been boosted by the newer engines, with 14min needed to reach 35,000ft and 31min to 45,000ft. Speed at 35,000ft is 430kt, and 405kt at 45,000ft.
Type certification is expected in the fourth quarter of 1999, with first deliveries slated to begin in the second quarter of 2000. The aircraft is being offered at just under $6.9 million in year 2000 dollars. Flight tests are "going smoothly", says Pierce, who adds that the plan is to transition to the Encore configuration with serial number 539 in 2000.
NEW CITATIONJETS
Cessna began deliveries of the CitationJet in 1993 and will hand over the 300th by the end of this year. As with its other principal products, Cessna holds a respectable order backlog, worth $180 million, for the entry-level business jet, yet the company is alive to the growing threats from Raytheon's Premier I and Sino-Swearingen's SJ30-2 light jets.
Cessna, therefore, decided to re-evaluate the CitationJet. "We received a lot of input from the Citation owner base," says CitationJet product manager Tom Aniello. The results of the study "-had to be appealing to current turboprop users and for companies buying their first aircraft", he adds.
The "wish list" spelled out what was needed and what should be retained from the existing aircraft. On the "must have" list were higher cruise speed, increased cabin room and greater range. On the "must keep" list were simple systems, excellent operating economics, low maintenance needs and "balanced performance".
The results were turned over to Cessna's advanced design team, which came up with the Citation CJ2. Although Aniello stresses that the new aircraft will not be a replacement for the CitationJet or the larger Bravo light jet, it is seen as complementary, with longer term potential.
To increase cabin space, Cessna began by stretching the CitationJet fuselage by 875mm and the tailcone by 425mm, to increase overall length to 14.2m. This provided room for six passengers plus crew and 3m3 (74.4ft3) of baggage space, as well as a full-size refreshment centre. An extra 0.9m was added to the wingspan, which grew to 15m as a result. The larger wing has 10% greater area and spreads the main landing gear track to 4.8m, some 0.9m greater than the current model. As with the Ultra Encore and other Citation models, the the new trailing-link gear will be standard with the CJ2.
The longer moment arm of the stretched fuselage required an extension to the horizontal stabiliser, which grows in area by 15%. As well as being extended to 6.3m in span, the stabiliser has been given a sweep of 20°,helping to reduce drag at the higher speeds planned for the CJ2. Maximum cruise speeds are expected to be around 20kt higher, at 400kt at 39,000ft. At higher altitudes, the delta increases even further to around 384kt at 41,000ft, or roughly 38kt higher than the CitationJet. The CJ2 will be certified to 45,000ft, compared with the current aircraft's ceiling of 41,000ft.
Pushing the CJ2 along at these speeds and altitudes will be the Williams-Rolls FJ44-2C turbofan. Flat rated at 2,300lb thrust at 20°C, the engine is 21% more powerful than the -1A powering the CitationJet. The FJ44-2C incorporates a 50mm greater diameter wide-chord, swept fan and three-stage low pressure compressor (LPC). The extra LPC stage accounts for the 170mm increase in length of the -2C versus the -1A. The engine will incorporate a new forced exhaust mixer and will retain hydro-mechanical fuel controllers for reliability.
The CJ2's standard avionics suite will be based around the Collins Pro Line 21 system and its 200mm by 250mm primary flight display and multifunction display. "It will be single-pilot qualified," says Aniello. The cockpit will also have digital dual-channel automatic flight control systems, a solid-state AHRS, AlliedSignal CNI-5000 panel-mounted radios (with 8.33kHz channel spacing for European requirements) and a Collins RTA-800 colour weather radar. AlliedSignal's KLN-900 global positioning/flight management system will also be provided as standard.
Avionics options include Universal UNS-1K or AlliedSignal Global GNS-X flight management systems, an RVSM certification kit, cockpit voice recorder and collision and terrain avoidance systems.
Maximum take-off weight will be 5,585kg, typical empty weight 3,550kg, and payload with full fuel and single pilot is expected to be around 270kg. Range (VFR) will be between 2,680km and 3,110km, with fuel consumption varying between 410kg/h at 393kt and 37,000ft and 320kg/h at 377kt and 43,000ft.
Airframe and Collins avionics carry a five- year parts and labour warranty, while the engines have a three year, or 1,500h, guarantee, whichever comes first. The base price for all this is just under $4.2 million until November, when it will rise.
The price has obviously been right for some already. Cessna released details of the CJ2 to its marketing force in August and by the time of the NBAA show, its orderbook is expected to be close to 80. The prototype is due to make its first flight in the second quarter of 1999, around six months after the show, and type certification is due to follow in the second quarter of 2000. Flight demonstrations will start at the end of that year and first delivery to the initial customer, also the first CitationJet customer, is due in the first quarter of 2001.
While the CJ2 is a step change beyond the current CitationJet, the company is conscious of the price rise and the threat of alienating a large section of the prospective entry-level marketplace as a result. Cessna has therefore worked on another set of improvements for the baseline CitationJet, which is now being dubbed the CJ1.
The block change will be initiated with aircraft serial number 360 in the first quarter of 2000, and essentially hinges around the upgrading of the cockpit with the Pro Line 21 system. Cessna is also building in a gross weight increase of 90kg over the CitationJet to allow a moderate increase in range and/or payload. MTOW will be 4,810kg, maximum landing weight 4,450kg (versus 4,400kg on the current aircraft) and range with three passengers will be 2,310km, or around 120km further. Typical full-fuel payload with a single pilot will be 305kg of passengers and baggage.
Standard avionics will include the Pro Line 21 displays of the CJ2 as well as the dual-channel autopilot, solid state AHRS, CNI-5000 radios, weather radar and KLN-900. The CJ1 will also be offered with all of the major avionics options available on the CJ2.
Although performance effects are expected to be negligible, the aircraft's extra weight means that balanced take-off field length is predicted to rise by around 200ft, to 3,280ft. The other effect is on price, which will rise from about $3.32 million for today's aircraft to around $3.39 million. With little in the way of certification work expected, first delivery will follow soon after the instigation of the block change in the first quarter of 2000.
With so many new Citation models in development, the company is re-organising its manufacturing site to handle a rapid rise in production. With annual production of the CJ1 and CJ2 alone expected to top 100 aircraft, it seems that the boom times are coming back to Cessna, and to Wichita.
PRO LINE 21 PASSES TEST
Several months of clandestine flight testing preceded Cessna's selection of Rockwell Collins' Pro Line 21 avionics system for the new Citation CJ1 and CJ2 business jets.
A CitationJet was equipped with the new flat-panel displays to prove the system's performance in a move which Collins believes signals a change in the way aircraft manufacturers select avionics suppliers. "They want low risk," the company says.
The Pro Line 21 system was launched in 1995 when it was selected for Raytheon's Premier I entry-level business jet. At that time, only prototypes of the large-format flat-panel displays had been test flown. Now Collins has delivered production equipment for flight testing in the Premier, which was expected to fly on the eve of NBAA.
Collins has continued to refine the system, introducing in the CJ1 and CJ2 "touch-recognisable" controls - switches, knobs and bezel-mounted buttons - which are placed, sized, shaped and textured "...to help the crew react instinctively, even under high-stress conditions."
The Pro Line 21 suite is based on Collins' Advanced Avionics System Architecture, an "operating system" which will form the basis of a range of avionics products for business and regional aircraft and large commercial and military transports.
The core of the system is an integrated processing centre in which multiple computation channels run layered, functionally partitioned software. This insulates the application software from hardware changes and facilitates software updates and hardware upgrades, Collins says.
The most visible aspect of the Pro Line 21 system is the 200 x 250mm "adaptive flight displays", for which Collins is now developing advanced graphics formats. The same flat-panel displays and modular avionics have been selected for the Bell Agusta 609 civil tiltrotor.
Source: Flight International
