PAUL LEWIS / WASHINGTON DC
Roll-out of the 728 brings Fairchild Dornier closer to becoming a major participant in the regional aircraft market
The German aerospace industry has long harboured ambitions to be a major player in the regional aircraft market. With the scheduled roll-out on 21 March of the Fairchild Dornier 728, it will move one step closer to realising that dream. The aircraft is the first of a planned new family of 70 to 110-seat transports purpose-designed for the emerging large regional jet market.
The German concept of a twin-turbine, short-haul aircraft dates as far back as the mid-eighties, and the planned MPC 75 joint venture between the then-MBB and CATIC of China. The proposed development went nowhere and became just another footnote in the long-running saga of abortive Sino-Western aerospace ventures.
But the idea for a large, five-abreast regional jet did not die there. It passed down through a succession of corporate entities from Deutsche Aerospace to Daimler-Benz Aerospace. It was finally revived as the 728/928JET following the 1996 purchase of Dornier Luftfahrt by Fairchild Aerospace.
The delay was perhaps fortuitous in that it allowed the regional jet market to mature further, and avoided the premature demise of earlier programmes such as the Fokker 70/100 and BAe 146/RJ. The recently renamed 728/928 family completes the line-up of contenders that will battle for a projected market of 4,000 aircraft in this size over the next 20 years. The Bombardier 70/78-seat CRJ700 is already in service, and will be joined in early 2003 by the 86/90-seat stretched CRJ-900. As an all-new design, however, its chief competitor will be the recently flown Embraer 170 and its larger 190 derivative.
Fairchild Dornier planning, which has just been refined, calls for a five-member family of aircraft, anchored by the baseline 728-100 and 95/110-seat stretched 928-100. Derivatives will encompass higher gross-weight, extended-range versions of both aircraft, notably the 728-200 and 928-200. Development of the latter will be accelerated by the proposed injection of over $930 million in additional funding from a combination of shareholder investors and German bank loans (Flight International, 22-28 January). The family will be completed by the even longer-legged Envoy 7 corporate transport version.
Reality check
The 728 has suffered from more than its share of programme delays and headaches, and for a time many observers doubted the aircraft would ever see the light of day. A take-over by Clayton Dubilier & Rice and Allianz Capital Partners, along with an accompanying $1.2 billion injection of fresh capital, finally shifted the programme into high gear in 1999. The delay in raising funds, combined with some early design changes increasing nominal capacity to 75 passengers, and a reality check by the new owners and pushed back the scheduled entry into service from May this year to July 2003.
There have since been other minor modifications - but the programme has stayed on track. Recent regulatory changes have required the installation of a pre-cooler downstream of the engine to lower bleed-air temperature and minimise the hazard of igniting fuel in wing tanks above the pylon. The heat exchanger will be a feature of the 728 from test aircraft No 3 (TAC 3). "That's the biggest design challenge we've had and, at this stage of the programme, that makes me feel pretty good," says Duncan Koerbel, Fairchild Dornier vice president 728/928/Envoy 7 programme office.
Fairchild Dornier hopes to have the lead test aircraft airborne in May, one year ahead of targeted type certification by the European Joint Airworthiness Authorities. This provides a three-month margin before the first production 728 is due to enter service with Lufthansa Cityline. The company has mapped out a 1,800h development and certification flight-test programme, which will span Germany, Spain and the USA, and involve four TACs and one production aircraft. Each aircraft will fly at approximately two-monthly intervals.
TAC 1 will be engaged in envelope expansion, airspeed/altitude calibration and testing flutter, handling qualities, hydraulics, flight controls, field performance and water ingestion. The second jet will be employed testing avionics, electrical systems, landing gear and icing using artificial shapes. TAC 3 will focus on the General Electric CF34-8D1 powerplant, Honeywell RE220 auxiliary power unit and the environmental control system, as well as hot and cold climate operations. TAC 4 testing will include pneumatic, fire protection and handling qualities evaluation. The initial production aircraft is to be used for cabin evacuation, internal and external noise, high-intensity radiated field and function and reliability testing.
Already "flying", and with around 2,000h on the clock is the 728 iron bird at Fairchild Dornier's Oberpfaffenhofen main plant. Engineers are hoping to use the rig to accelerate development and reduce flight-test time by earning certification credits in areas of system validation and fault isolation. "We're on the right path with required test points, and the things we want to prove in time to support first flight. Downstream of that, our intention is to conduct testing on the asset that conforms with the test article and gets us credit by showing our method of compliance with regulatory requirements," says Koerbel.
Trading off
Load testing of a static airframe, which will be the third aircraft off the line after TAC 2, is due to commence before first flight and will run until early next year. Fatigue testing on a second airframe is due to start in the second half of this year, and will run to 200,000 cycles - 2.5 times that of the 728-100's maximum design life. The heavier and longer-range 728-200 and 928-100/200s are designed to a 65,0000 cycle life, while the Envoy 7 will trade off a higher 39,500kg (87,000lb) maximum take-off weight (MTOW) and 7,400km (4,000nm) extended range for an even lower 25,000-cycle ceiling.
Fairchild Dornier plans to certificate the 728-100 at an upper weight limit of 36,000kg, while offering a lower "normal" weight of 35,000kg. With the extra funds it plans to accelerate development of the follow-up -200 by nine to 12 months and certificate the aircraft by the end of 2003. The aircraft will have a 38,000kg MTOW, which will translate into around 740km more range. It will conform aerodynamically to the basic -100, but feature strengthened outer wing panels, horizontal stabiliser, reinforced fuselage and landing gear. The aircraft will powered by the CF34-8D3 turbofan offering a 3% hike in power over the -8D1's 12,500lb-thrust (56kN) rating. But unlike the earlier proposed 728JET-ER, there are no plans to extend the wingtips.
"We always planned to do an extended-range version of the 728 and designed the aircraft to operate at higher gross weights. In response to major airlines like British Airways and Qantas, which want to see as much capability as they can as part of their evaluations, we're going to accelerate development of the 728-200. Most of the flight testing we do on the 728 at 36,000kg will apply to to the -200, as it is close enough in weight that we'll get credit - and since it is aerodynamically the same external configuration that will not be an issue. That will leave us with a two month -200 flight test programme," says Koerbel.
EADS Casa is due to deliver a strengthened 728-200 wing in early 2003, which will be mated in the spring with a reinforced fuselage, and rolled off the final assembly line in the summer. Structurally, the 728-200 will be identical to the 39,500kg Envoy 7, minus the corporate jet version's winglets and additional underfloor auxiliary fuel tanks. At the conclusion of the -200 flight-test programme, the aircraft will retrofitted with Fairchild Dornier's trademark 'Super Shark' wingtip treatment, and join the Envoy 7 flight-test programme. It is estimated that the distinctive hybrid winglet/raked wingtip will reduce overall drag by 3.5% and generate a 5% or greater saving in fuel burn.
The addition of belly tanks will increase the aircraft's maximum fuel load to 15,200kg, an increase of around 50% over the baseline 728-100. The other major difference is the aircraft's uprated 13,050lb-thrust CF34-8D6 powerplant, which offers 6% more power than the -8D1. The Envoy 7 will carry up to eight passengers over a maximum range of 7,400km, or alternatively accommodate up to 18 occupants at reduced range. The aircraft will include an expanded 7.8m3 (220ft3) of baggage space under floor and in the rear of the cabin.
There will be three aircraft in the Envoy 7 development programme, including the modified 728-200, with flight tests to start in July next year. The company plans a much longer flight test programme for the Envoy 7 than the -200, stretching over 19 months and with supplemental type certification of a customised aircraft, complete with executive interior, not expected before September 2004. Fractional-ownership operator Flight Options has ordered 25 of the aircraft and will be the first to receive the Envoy 7.
Next in line to the Envoy 7 on the development schedule is the stretch 928-100 and extended-range -200 version, which are due to enter service in early 2005. Fairchild Dornier has mapped out a 27-month flight-test schedule involving three dedicated test aircraft, the first of which is scheduled to fly around November next year. The company will not be required to produce new static test articles, but, rather, conduct additional load and fatigue tests on partial 928 subassemblies.
Type certification
Testing will be conducted at the 928-200's increased 49,700kg MTOW, with the 4,000km extended-range version targeted for type certification in September 2004, followed a month later by the -100. Bavaria International Leasing has so far ordered four of the aircraft plus two options.
Principal design differences include extending the forward and aft fuselage sections each by 2.03m and adding a new mid section. This provides for an extra half dozen five-abreast seat rows, increasing the cabin capacity to 100 seats in a 32in (810mm) pitch. This is the maximum permissible occupancy stretch without having to add emergency overwing exits. A 1.69m (5.5ft) wider wingbox increases the 928's wing area to 84.4m2 (908.5ft2), but the outboard wing sections will remain common with the 728. There will be the option to add the Super Shark winglet later to either.
Fairchild Dornier has yet to finalise its line-up of 928 risk-sharing partners, and appears to be using the pause in the programme to ensure it is getting the best value out of its current 728 team-mates. Several companies nonetheless have begun working on the 928, with EADS Casa having completed a preliminary wing design and Goodrich looking at a new main landing gear to support the 50,000kg aircraft. The 928-100 series will be powered by the new CF34-10D5 engine rated at 17,355lb-thrust and the 928-200 by the -10D6, which has 8% more power. Both engines will incorporate a wider 53in- (1.35m) diameter fan, wide-chord blades, three-stage booster and increased pressure ratio.
The 728/928 programme has been structured from the outset to reduce the time it takes to build the aircraft and minimise its exposure to Germany's notoriously high labour costs. The number of first-tier, risk-sharing partner suppliers has been kept to 58 - compared with nearly four hundred suppliers on the smaller 328JET - and they account for around 80% of the aircraft by value. Partner responsibilities are not confined just to design and certification, but extend to sourcing and integrating second-tier suppliers. "We'll be able to assemble the aircraft in about one third of the time it would take with an aircraft designed differently," says John Wolf, Fairchild Dornier chief operating officer.
Fairchild Dornier has invested more than $90 million in new equipment to produce the aircraft, including new computer software such as SAP R/3 for material management and the CATIA design system from Dassault SystŠm. The company has extended this process to digitally mapping out and simulating production tooling and processes using Tecnomatix's eM-Plant software. This ranges from a three-dimensional replication of the simplest of actions, such as a worker accessing fasteners, to simulating the 728's entire final assembly process.
The same digital manufacturing team has also been instrumental in designing a new final-assembly hangar and a separate customisation building outfitted with docks. "The biggest part of a variable comes with customisation. We'll have the flexibility to do different lead times and vary the input and output. Where we can get things to a schedule, with the same people consistently doing something, we've done that," says Ray Edwards, senior vice president production.
The company has equipped itself to build up to 120 aircraft a year. But in the light of the decision to accelerate the 728-200 and 928-200, this is likely to be reviewed. Fairchild Dornier has also said it will have to decide at some stage on adding a third baseline model to the family. This could be the proposed 528, a 55-seat shrink derivative, or a further 120/130-seat stretch development of the 928 that is being called the X28. "We're funding in our plan to develop another model, the options are go a little smaller or make the 928 larger. We continue to look at both sides and we'll pick one that makes the best business case." says Koerbel.
Source: Flight International
