pdate: Canadair Challenger 604

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1 PILOT REPORT U pdate: Canadair Challenger 604 Canadair stretches the range of its wide-cabin business aircraft. By FRED GEORGE November 1993, Document No (6 pages) In little more than two years, the cost of buying a 4,000-nm range, widebody business airplane is going to drop by $4 million to $7 million. That is when Canadair s Challenger 604, with an estimated $20-million completed price, is scheduled for its first customer deliveries. Even after the first production 604 airplanes are delivered in late 1995, it will take a sharp business aircraft spotter to tell the difference between Challenger 601s and 604s. Most of the changes are internal. Among the significant ones, Collins avionics dominate the instrument panel (see sidebar). Changes to the center wing box fuel tanks, after equipment bay saddle tanks and an enlarged tail cone tank add an extra 2,214 pounds of fuel that helps to boost the range by 415 miles. And internal improvements to the Challenger s engines that better specific fuel consumption by up to three percent also enhance the range of the aircraft. Externally, few clues will be noticeable other thanthe stamping on the data plate. The extra fuel and the more robust airframe structure needed to carry it made it necessary to increase the 604 s maximum takeoff weight (MTOW) by 2,500 pounds now up to 47,600 pounds. Beefed up rolling stock, capable of handling the additional weight, will protrude slightly from the wheel wells, causing slightly more form drag. Canadair is designing a new wing-to-fuselage belly fairing to minimize the aerodynamic impact of the larger landing gear, and the firm s engineers estimate that a net drag penalty of about two percent will result. Canadair makes no pretense abound the 604 being a clean sheet design. The company chose to develop a fourth iteration of the original Challenger 600 after several market studies. The firm concluded that 95 percent of the potential buyers of the 604 already operated other Challengers, so there was no particular advantage in pursuing other buyers in the concept market to expand market share. The derivative approach has met the needs of the manufacturer well in the past, resulting in incremental performance increases at relatively affordable prices. A little more than four years ago, Canadair considered developing a 4,000-nm, seven-foot stretched version of the 601 called the Challenger EJ. That aircraft would have used the Canadair Regional Jet s (RJ) wing, but it would have needed new engines in the poundsthrust class because of its much increased MGTOW. Substantial development and certification costs would have been involved, and those costs would have been passed along to the consumer. Canadair concluded that the global economic recovery was not going to happen any time soon and that the market was quite sensitive to large price escalations for new aircraft. The firm talked extensively with its Challenger 601 operators who said more range was a much higher priority than a longer cabin especially if

2 more interior room would cost a lot more money. Therefore, the firm opted for the derivative 604 design with 4,000-nm range, the same cabin size and upgraded CF34 turbofan engines. The result? The newest Challenger will be the least-expensive widebody business airplane that can fly non-stop from Chicago to Munich, Tokyo to Seattle or Paris to Washington. DESIGN DETAILS Every aircraft design is a blend of tradeoffs, and the 604 is no exception. The new airplane s extra 415 miles of range cost three passengers in tanks-full payload compared to the Challenger 601-3R. But it can carry eight passengers 3,600 miles at 0.8 Mach normal speed cruise almost 11 percent farther than its predecessor with the same 1,600-pound payload traveling at the same speed. The 604 has a high-speed cruise of 0.83 Mach, but Canadair doesn t publish range numbers for that speed. The gap between the two aircraft narrows but does not close when the 604 is flown at 0.8 Mach normal cruise, and the 601-3R slows to 0.74 Mach longrange cruise (LRC). The 604 will be able to fly five passengers 3,750 miles at normal cruise; the 601-3R, carrying the same 1,000-pound payload, can fly only 3,585 miles at LRC. Canadair anticipated that the 604 s 4,000-nm range at 0.74 Mach long range cruise would be used for extended over-water operations, so several systems will be upgraded to assure optimum reliability. The airplane will be fitted with General Electric s latest -3B version of the CF34 high-bypass-ratio turbofan engines that have external dimensions identical to the -3A1 engines mounted on the 601-3R and the Challenger RJ. The -3A1 and the -3B are both rated at 8,729 pounds-thrust for takeoff. However, internal improvements including a first-stage blisk (bladed disk) instead of individual blades on a separate disk, more aggressive scheduling of the variable inlet guide vanes and stators and better sealing endow the latest - 3B version with a slightly higher overall pressure ratio and wider operating temperature margins. The internal improvements will increase the weight of the -3B by no more than 15 pounds, according to General Electric. The improvements, though, give the -3B better density altitude performance that is especially apparent during warmer than standard day departures and high-altitude cruise. For example, the -3B engines will be able to maintain takeoff-rated thrust to sea level 86 F, which is equivalent to a seven-percent boost in available thrust. It also will produce two to five percent more climb thrust and yield about two percent more high-altitude cruise thrust while achieving two to three percent better thrust specific fuel consumption (TSFC). The 604 fuel system s new aft saddle, rubber bladder tanks and enlarged tailcone tank, when filled, obviously will move the center of gravity farther aft compared to that of the 601. That s good for the fuel economy because shifting the c.g. aft reduces the amount of downward lift (from the horizontal tail) that is needed to keep the aircraft in trim. Less downward lift results in less induced drag and lower fuel consumption. However, the aft c.g. design feature also makes proper fuel system operation much more critical, so certain components will be upgraded to ensure rock-solid system reliability. Solid-state fuel level sensors will be installed in each tank. The aft tanks will be fitted with dual fuel pumps and a fuel dump to ensure that the aircraft remains within the allowable c.g. limits under any condition. A computer will control the entire fuel system to ensure optimum weight distribution during flight and also during refueling. Other systems also will be upgraded, such as the electrically-driven hydraulic pumps and various hydraulic system components, the horizontal stab trim system, the wheel brake anti-skid system and the landing gear proximity switches. Many of these small reliability improvements evolved from Canadair s experience with the RJ, itself a derivative of the Challenger 601-3A. The 604 will get a new avionics suite one that is quite different from the 601 s Honeywell SPZ-8000 integrated avionics package. A Collins Pro Line 4 panel will be installed, supplemented by Litton ring laser gyro inertial reference units and flight management systems that have yet to be selected (see sidebar). Interior furnishings for the 604 will be identical to the 601-3R s. Canadair plans a relatively liberal 3,600- to 4,200-pound weight allowance for the interior. (Our specification box is based on Canadair s 3,800-plus pound interior weight allowance.) Thus, individual customer preferences should be accommodated without much loss of the aircraft s useful load. PERFORMANCE CHARACTERISTICS The 604 has the same sea-level, standard day takeoff thrust as the 601, but its MGTOW is more than five percent heavier. Therefore, its thrust-to-weight ratio at takeoff will not be as sprightly as that of the 601-3R. However, a change to the FAR Part 25 transport category airplane certification rules regarding V-speed calculations will help Canadair reduce the adverse effect the additional weight would otherwise have on takeoff field length performance. The latest version of Part 25, which sets forth the rules used for Canadair RJ certification, permits certain takeoff V-speeds to be reduced by one-half of the margin

3 Collins to be Avionics System Integrator The Challenger 604 is the latest in a series of recent Bombardier aircraft that will be fitted with a Collins avionics package. The Canadair RJ and the Learjet 60 also use a Pro Line 4 integrated avionics system, but Collins will play a larger role on the Challenger 604. The Cedar Rapids firm will supply its own equipment and ensure other vendors avionics work in harmony with all components in the system. Collins will send a team to Montreal to work with Canadair and other vendors daily to iron out all the design wrinkles during the 604 s compressed development cycle. This will be the most concurrent avionics engineering program Canadair ever has attempted and it will cut several months out of the certification process. One of Canadair s goals was to fit the Challenger 604 with airline-proven components, and that is a prime reason Pro Line 4 avionics were chosen for the newest Challenger. The RJ s Collins avionics package has been subjected to tough, high-cycle, highutilization operations, and it has come through with flying colors, according to Canadair. On the newest Challenger, the Pro Line 4 avionics system is based on the same technology and many of the same components, but it will be tailored to the long-range, extended overwater mission of the 604. Six inch CRT displays-left- and right-side Primary Flight Displays and Multi-Function Displays, plus an Engine Instrument and Crew Alerting System (EICAS) dominate the instrument panel. The EICAS will have six pages (different screen displays) that will include synoptic graphics for the AC and DC electrical systems and the flight control system. The hub-and-spoke architecture Pro Line 4 system utilizes Integrated Avionics Processing System (IAPS) boxes at the center hub. These are linked to various components by means of ARINC 429 spokes, among other industry standard interfaces. The IAPS will contain dual digital flight control systems, with dual flight director computers, fail passive autopilots and yaw dampers. The IAPS also will have a comprehensive maintenance and diagnostic computer designed to be linked with components other vendors supply, as well as with Collins boxes having their own internal diagnostic functions. The system will have an operatordefined, operator-maintained checklist function. Other components at the ends of the spokes include dual Data Concentrator Units (DCUs)-similar to those in the RJ-that collect and distill data Tom several sensors and then send them on the IAPS in ARINC 429 form. The package also includes dual digital air data computers, dual Pro Line 400 all-digital interface comm/nav/pulse radios and dual HF-9000 high frequency radios. The 604 will be fitted with a Collins TWR- 850 all-solid-state turbulence detection radar. Dual Litton LTN-101 Flagship ring laser gyro inertial reference systems will supply the system with attitude and acceleration information. Dual Flight Management Systems (FMS) will be part of the package and will most likely be supplied by either Universal Navigation Systems or AlliedSignal s Global Wulfsberg Systems subsidiary (although the FMS Control Display Units- CDUs-in our artist s rendering show the Collins label). The 604 s instrument panel and console layout is quite different from that of the RJ. The FMS CDUs will be located well aft in the triple-width console, behind the full-color Radio Tuning Units. The Electronic Flight Instrument System and EICAS display tubes are much larger than those in the RJ, so some of the components that were formerly located in the panel had to be moved to the console. The only conventional analog steam gauges remaining in the instrument panel are the standby instruments- airspeed indicator, attitude indicator and altimeter. Global Positioning System sensors and a Traffic Alert and Collision Warning System (TCAS II) will be available as options. Other options include a third DCU (two are needed for dispatch), a third VHF comm radio, a left- and rightside, split scan radar function, a second radio altimeter, a third IRS and a third FMS, a BFGoodrich Stormscope electrical storm detection system and a Ground Proximity Warning System. The entire package will occupy the same space, or less, than the avionics package in the 601-3R, but it will offer more capability. Collins estimates that its Pro Line 4 avionics suite will weigh about 20 pounds more than the one installed in the 601-3R, but Canadair engineers say Collins has a reputation for finishing under its weight budget.

4 over the stall speed if the aircraft is equipped with a stall warning stick pusher. The regulations, for example, allow the minimum V 2 takeoff safety speed to be reduced from 1.2 to 1.13 Vs1, and the VREF landing reference speed to be reduced from 1.3 to 1.23 VSO. The reduced V-speeds result in a takeoff field length increase of about two percent in spite of the 604 s five percent additional MGTOW. A new landing gear system also gives the 604 s airport performance a boost. Its heavier rolling stock uses some of the RJ s anti-lock braking system components, but few other components are shared. The carbon wheel brakes have 50 percent more stopping power compared to the 601 s, resulting in better wear characteristics and better brake efficiency. Larger tires also give the 604 a bigger footprint and, thus, lower pavement loading. (The RJ s steel brakes that are so well-suited to high cycle, heavy-duty operations simply weigh too much for use on the longrange mission profile 604.) Canadair claims that the reduced V-speeds and brawnier carbon brakes limit the increase in the 604 s balanced field length (BFL) at MGTOW only 110 feet compared to its lighter predecessor, an aircraft that wasn t able to take advantage of the reduced V-speed rules. A fully loaded 601-3R has a BFL of 6,050 feet at sea level on a standard day. In contrast, a 604 at MGTOW will require no more than 6,160 feet of runway for an ISA/SL takeoff, according to Canadair. The extra climb and cruise thrust of the -3B engines more than offsets the 604 s increased MGTOW after takeoff and during the remainder of the flight. Both the 601-3R and the 604 have a published initial cruising altitude of FL 370 on an ISA day, and both aircraft have a maximum certificated altitude of FL 410. Canadair s engineers estimate that a fully loaded 604 actually will be able to climb directly to FL 390, although the last 2,000 feet of the climb will take 10 Takeoff Weight (lbs) Distance (nm) 48,000 46,000 44,000 42,000 40,000 38,000 36,000 34,000 32,000 30,000 4,000 3,500 3,000 2,500 2,000 1,500 1, nm 1,741 lb Conditions: NBAA IFR reserves; zero wind; ISA;0.74 Mach long-range cruise; max cruise altitude, FL nm 3,598 lb 308 nm 1,638 lb minutes. Warmer than standard day conditions will limit the initial cruising altitude to FL 370, but a fully loaded 604 should be able to shave almost 20 percent off the time to climb to that altitude, compared to the time a 601-3R would require. The 604 s mid- to high-thirties design cruise point 28, ,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 Source: Bombardier, Canadair Challenger Division All data preliminary Conditions: 1,000-lb payload (5 pax); NBAA IFR reserves; max cruise altitude, FL 410; zero wind; ISA 1,231 nm 5,554 lb 730 nm 3,245 lb Source: Bombardier, Canadair Challenger Division All data preliminary RANGE/PAYLOAD PROFILE TIME AND FUEL VERSUS DISTANCE 1,687 nm 7,586 lb 1,153 nm 4,912 lb Range (nm) 2,143 nm 9,708 lb 1,577 nm 6,638 lb 2,599 nm 11,930 lb 2,000 nm 8,434 lb 3,055 nm 14,255 lb 2,423 nm 10,318 lb 3,509 nm 16,683 lb 2,846 nm 12,275 lb 3,752 nm 18,025 lb 3,269 nm 14,310 lb 4,000nm 18,025 lb 3,692 nm 16,427 lb High-Speed Cruise Long-Range Cruise Time (hrs) Zero Payload 400-lb Payload 1,000-lb Payload 1,600-lb Payload

5 means that operators should plan on using the published North Atlantic Track System when flying between Europe and North America. For example, when traveling westbound, operators should plan on initially using FL 350, then stepclimbing to FL 390 in the tracks. The Challenger 604 will offer more operating flexibility than its predecessor because its maximum landing weight will be 2,000 pounds higher now up to 38,000 pounds. It will have an estimated manufactured empty weight of 21,356 pounds 871 pounds heavier than a 601, according to Canadair. B/CA estimates that the additional weight will give the 604 a basic operating weight of 27,121 pounds. That still leaves more than 1,100 pounds of additional fuel available following an unrefueled stopover, about enough for an additional 180 miles of range compared to the 601-3R. That gives the Challenger 604 transcontinental range following such a stopover. For instance, the 604 will be able to depart from Los Angeles, land at Orlando and then fly on to San Diego without taking on additional fuel, assuming no-wind conditions. ACQUISITION AND OPERATING COSTS What the 604 gives up to some heavy-iron competitors in performance, it makes up for in predictable operating economics. According to Canadair, the 604 has lower overall life cycle costs than any business aircraft in its class. First, look at the 604 s acquisition cost. It will be delivered green at a price of $17,950,000 (1993 dollars). The estimated $20-million price complete includes Canadair s cost allowance of $2,150,000 for exterior paint and an interior. Canadair claims that the 604 will burn less fuel than the 601-3R and,

6 PRELIMINARY SPECIFICATIONS CANADAIR CHALLENGER 604 Equipped price $20,000,000 (Estimate) Seating 2 +8/19 Engines Model 2 CF34-3B Thrust 8,729 lbs ea. TBO 6,000 hrs Dimensions (See three-views) Weights (lbs/kgs) Max ramp 47,700/21,637 Max takeoff 47,600/21,591 Max landing 38,000/17,237 Max ZFW 32,000/14,515 BOW 26,630/12,079 Max payload 5,370/2,436 Useful load 21,070/9,557 Max fuel 20,000/9,072 Fuel w/max payload 15,700/7,121 Payload w/max fuel 1,070/485 Limits Mmo 0.85 VMO 345 KIAS VFE (app.) 230 KIAS Pressurization 8.8 psi Performance Climb All-engine (fpm/mpm) 4,150/1,265 Engine-out (fpm/mpm 1,100/335 Gradient (ft/nm,m/km 347/106 Ceiling Certificated (ft/m) 41,000/12,497 Service (ft/m) 39,000/11,887 Engine-out (ft/m) 16,900/5,151 Sea level cabin (ft/m) 23,200/7,071 FAR Part 36 Noise Levels Not available Airport Performance (See charts) Range Performance (See charts) hot section inspections at 3,000 hours, $60,000 for routine line service during the overhaul interval and $500,000 per engine for engine overhaul at 6,000 hours. (General Electric does not offer an hourly engine service program for the CF34 turbofan engine.) The Pro Line 4 avionics suite on the Canadair RJ has earned a reputation for reliability, and it forms the basis of the Collins package in the 604. Collins is going to join Canadair s Smart Parts program that pays for virtually all consumable and rotable parts for a fixed hourly fee. Airframe, systems, engine and avionics costs are all included in Canadair s Smart Parts. General Electric emphasizes that more than 800,000 hours have been accumulated on the CF34, and more than 10 times that amount of time on the military version the TF34 used on the U.S. Navy s S-3 Viking and the U.S. Air Force s A-10 Warthog. Therefore, Canadair officials feel the combination of the Smart Parts program and the proven reliability of the CF34/TF34 engines should expose operators to very little unforeseen operating expense. In fact, Canadair is banking on a blend of improved performance, first-rate product support and iron-clad operating cost predictability to ensure the success of the Challenger 604. According to some Challenger fleet operators with whom we spoke, the firm is right on target in its pursuit of these goals. Doubtlessly, business aircraft operators are more conscious of acquisition and operating costs than ever before. Canadair is betting that such cost awareness is more important to Challenger operators than additional cabin space, higher cruise altitudes and five percent more range. If the firm wins that bet, the 4,000-nm Challenger 604 could become a benchmark in the history of business aircraft development. The overall operating economics of a large business airplane finally will have become as valued a design priority as speed, range and payload. B/CA thus, will become the heavy-iron business airplane class leader in fuel efficiency. Fuel consumption, though being one of the most predictable operating costs, is only one component. Canadair s customers said they want consistent fiscal year and quarter-to-quarter operating cost predictability including turnkey support, virtual operating cost guarantees and absolutely no surprises. The 604 should deliver on those pledges. Challenger maintenance support already is regarded highly in the business aircraft community. For example, General Electric claims that the durability improvements to the CF34-3B engine will result in overall operating costs equal to or less than the -3A1 s current $101 per hour. That s based on $50,000 for