Dornier 328 Corporate Shuttle

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POWER BY PRATT AND WHITNEY The Do 328’s PW119 turboprops are mature engines that benefit from the millions of flight hours of experience gained since the PW100-series was introduced in the early 1980s. Other versions of the PW100 power the ATR 42/72, Canadair CL-415, de Havilland Dash 8, Embraer EMB-120 Brazilia and Fokker 50. The PW100 series uses a conventional, hydromechanical fuel control augmented by a supervisory electronic control unit for improved response and efficiency. Power and condition levers control almost all engine functions, thereby eliminating the need for third levers in the throttle quadrant. Fitted to the 328-110, the PW119B combines the air-inlet geometry of the PW118A with a larger compressor section adapted from the 2,950 tshp PW124, plus a robust hot section borrowed from the 3,200 tshp PW127. On paper, that should work out to a maximum takeoff flat-rating of 2,180 shp up to 31°C (88°F), and 1,851 shp up to 48°C (119°F) for normal operations. Installation losses, though, cut the flat-rating of the PW119B to 20°C (69°F). The PW119C, a 2,180-shp engine with five percent more thermodynamic horsepower that will provide improved hot-and-high airport performance, will be offered on the Dornier 328-120. The PW100 has a three-spool design that is unique to this class of engine. The gas generator has a low-pressure spool mounted on a concentric shaft that is mechanically separate from the high-pressure spool. The low-pressure, centrifugal-flow compressor’s output is ducted through a series of external diffuser tubes into the inlet of the high-pressure, centrifugal-flow compressor. Downstream of the reverseflow combustor is a single-stage, high-pressure compressor turbine, followed by a single-stage, low-pressure compressor turbine. As a result, each of the compressor spools can rotate at its optimum speed. The two-spool design reduces the power required for starting because of the relatively small rotating mass of the high-pressure compressor. In addition, the low-pressure compressor can rotate freely, not unlike a turbocharger for the high-pressure core. For example, while the overall pressure ratio is a relatively modest 16:1, the PW119B can produce up to 1,523 shp (uninstalled) with a 0.439 specific fuel consumption (SFC) at FL 250. Aft of the compressor turbines, there are two low-pressure power turbines linked to the forward prop gear box by means of a third, inner shaft. The prop is a six-blade, dual-acting, graphite composite Hartzell design. Prop speed for takeoff is 1,300 rpm, with 1,100 rpm for climb and 1,050 rpm for cruise. PWC’s Eagle Service Plan is available for the PW119 at a cost of $106.05 per engine, per hour—based on no more than one cycle per hour and less than 500 flight hours per year. Corporate and regional operators, however, report they are flying more than one cycle per hour, which would result in a higher operating cost. (The cost per hour varies directly with cycles per hour and inversely with hours per year.) The engine is covered by a 1,000 hour, two-year warranty and an extended service program. In the forward section of the cabin, the Corning aircraft are equipped with 41-inch-long coat closets. Aft of the galley is a 222-cubic-foot pressurized cargo bay, capable of holding 1,650 pounds. The cargo bay is equipped with both a 55-inch by 36-inch external door and a door in the aft cabin for inflight access. The other two U.S. corporations that operate Do 328-110 corporate shuttles in the United States have more conventional, airline-style interiors. One company removed one row of three seats, thereby reducing the seating capacity to 27 passengers, but extending the seat pitch to 35 inches. The other firm is operating the aircraft in a standard 31-seat configuration. MISSION PROFILE Corning’s missions average about 200 nm with a block time of 45 to 50 minutes and a 900-pound approximate fuel burn, according to Schultz. He said the block times are slightly longer than Dornier’s mission-planning guide forecasts, because Corning uses a reduced cruise power setting to prolong engine life, and that results in 325 KTAS cruise speeds. Another corporate operator confirms similar block times for 200-nm average missions, but reports fuel burns of about 1,000 pounds per leg due to relatively low cruise altitudes in the high teens and low twenties. The Do 328-110 saves both time and operating cost compared to the G-I shuttles formerly in service with the The engine nacelles have large doors on each side, providing excellent maintenance access. three U.S. corporate operators. Schultz commented, “It’s a wonderful G-I replacement.” For example, the Do 328’s block time from Elmira, New York to Wilmington, North Carolina is 1+40, and its fuel burn is 2,200 pounds. The G-I completed the trip in two hours with a 3,300-pound fuel burn. Shorter legs widen the fuel-savings gap between the Dornier and the G-I, another operator commented. Fred George FROM MARCH 1996 BUSINESS & COMMERCIAL AVIATION. © 1996, THE McGRAW-HILL COMPANIES, INC. ALL RIGHTS RESERVED.
ANALYSIS Cabin Pressurization 6.8/3 Cabin Length 33.9/2 Cabin Height 6.2/2 Cabin Width 7.2/2 Max Payload 8,135/3 Fuel (Max Payload) 3,219/2 Ratio: Max Payload/BOW 0.414/4 Ratio: Useful Load/BOW 0.577/4 Ratio: Landing Weight/MTOW 0.983/1 TFL (SL/ISA) 3,570/1 TFL (5,000 ft, ISA+20°C) 5,495/1 Climb Rate 2,060/1 Service Ceiling 31,000/1 Time (240-nm Mission) 59/1 Block Fuel (240-nm Mission) 1,180/4 TAS (High-Speed Cruise) 329/1 Specific Range (High-Speed Cruise) 0.257/5 Range (Max Payload) 829/3 Range (Max Fuel) 1,945/1 Tradeoffs are a reality of aircraft design, although aeronautical engineers attempt to give each model exceptional capabilities in all areas at an affordable price. The laws of physics, however, do not allow one 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 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 we compute the percentage differences between the parameters of the subject aircraft and the composite numbers for the competitive group as a whole. Those differences are presented in bar-graph form, and the absolute value of the parameter under consideration, along with its rank with respect to the composite, are given. For this Comparison Profile ® , we present selected parameters of the Dornier 328-110 in relation to a composite group consisting of the de Havilland Dash 8-100, Embraer EMB-120 Brasilia, Jetstream 41 and Saab 340. We’ve omitted the comparisons for 1,000-nm trip and long-range cruise performance, except for max payload range, because of incomplete data. We have, however, included a comparison of 240-nm trip performance which actually is more representative of the mission profile typical of this class of aircraft. The Comparison Profile ® is meant to illustrate the relative strengths and compromises of the subject aircraft; it is not a means of comparing specific aircraft A third corporate operator that flies eight 140-nm legs per day reported 315 KTAS cruise speeds at 16,000- to 17,000-foot altitudes with block-toblock fuel burns of 900 pounds. The G-I previously operated by the firm on this route consumed 1,200 to 1,450 pounds on each leg. Schultz said Corning’s average load factor is 95 percent. The direct operating cost (DOC) is $495 per hour, not counting an estimated $110 per hour that could be reserved for engine and prop restoration. Other operators that fly shorter average legs report DOCs of $600 to $650 per hour, including engine and prop reserves. Regional-aircraft operators also say that Dornier’s cruise speed and fuelburn predictions are accurate for the aircraft. Some of these operators also are using reduced power for lower engine maintenance cost, but they still claim to achieve cruise speeds of 310 to 315 KTAS at FL 310. SPECIFICATIONS DORNIER 328-110 B/CA Equipped Price $10,000,000 (B/CA Estimate) Characteristics Seating 2 + 12/19 Wing Loading 71.6 Power Loading 7.07 Noise (dBA) 81.7 Dimensions (ft/m) External Length 69.8/21.3 Height 23.7/7.2 Span 68.8/21.0 Internal Length 33.9/10.3 Height 6.2/1.9 Width 7.2/2.2 Floor Width 7.2/2.2 Power Engines 2 P&WC PW119B Output 2,180 shp ea. TBO 7,000 Weights (lb/kg) Max Ramp 31,019/14,068 Max Takeoff 30,843/13,988 Max Landing 29,167/13,228 Zero Fuel 27,800/12,608c BOW 19,665/8,918 Max Payload 8,135/3,689 Useful Load 11,354/5,149 Exec Payload 3,200/1,451 Max Fuel 7,518/3,410 Payload/Max Fuel 3,836/1,740 Fuel/Max Payload 3,219/1,460 Fuel/Executive Payload 7,518/3,410 Limits MMO 0.59 VMO/FL 270/20,363 PSI 6.8 Airport Performance (ft/m) TOFL (SL, ISA) 3,570/1,088 TOFL (5,000 ft, ISA+20°C) 5,495/1,675 Mission Weight 30,314/13,748 (Hot/High MTOW Limit) V2 VREF 125 (at MTOW) 101 (at Max Landing Weight) Landing Distance 2,340/713 Range NBAA/IFR (nm/km) 1,977/3,661 Climb All Engine (fpm/mpm) 2,060/628 OEI (fpm/mpm) 495/151 Gradient (ft/nm) 836 Ceilings (ft/m) Certificated 31,000/9,448 DO 328 FUTURE ENHANCEMENTS Dornier has delivered more than 50 Do 328 aircraft out of 78 orders and 76 options. The production rate is three aircraft per month. By the first quarter of this year, all -100 aircraft should have been upgraded to the -110 configuration at no charge to customers. FROM MARCH 1996 BUSINESS & COMMERCIAL AVIATION. © 1996, THE McGRAW-HILL COMPANIES, INC. ALL RIGHTS RESERVED.
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Page 5: ANALYSIS STRUCTURE AND SYSTEMS Cons
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Dornier 328 Corporate Shuttle

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