PAUL LEWIS / WASHINGTON DC
Innovation is a key factor in enabling Embraer to keep to an aggressive development schedule for its new regional jet, the ERJ-170
When Embraer began considering options for a follow-on to its highly successful ERJ-145 series in 1998, speculation centred on either a low-risk derivative stretch of its 35- to 50-seater product line or a collaboration with another regional aircraft player, such as ATR.
Instead, the Brazilian manufacturer announced to the world in February 1999 that it had taken the commercially brave decision to develop its own all-new 70- to 90-seat regional jet family.
The rationale for an entirely new design for the ERJ-170/190 was clear, given that the three-abreast ERJ-145 would not have made a good derivative building block without a new cabin cross-section. Embraer also wanted the option of stretching the four-abreast concept into the 100-seat arena. The company's decision to retain design leadership also avoided the potential pitfall becoming involved in cumbersome collaborative negotiations.
While some rival programmes have fallen by the wayside or slipped, Embraer has adhered to an ambitious 42-month development and flight-test schedule. The first prototype is due to roll out of the company's Sïo José dos Campos plant on 29 October, around 28 months after the programme was formally launched off the back of a $4.9 billion order from Swiss regional carrier Crossair. The company hopes to fly the aircraft as early as next month, with European Joint Aviation Authorities (JAA) JAR 121 certification and first delivery scheduled before the end of next year.
Virtual reality centre
"The assembly of the first aircraft has gone extremely well," says Luis Carlos Affonso, Embraer ERJ-170/190 programme director. "We have had all the structural parts mating very well and so have spent less time in final assembly. This is thanks to the design tools we're using, the virtual reality centre as well as having the partner suppliers sit together. We've been able to keep our schedule in part because of that."
Within a month of launching the programme, Embraer initiated a joint definition phase (JDP) bringing together an international team of 16 risk-sharing partners from seven countries. By the time the ERJ-170 concluded JDP in February 2000, 600 engineers located in Sïo José were working on the preliminary design, of which only half were Embraer employees.
One of the JDP's main objectives was to construct an electronic mock-up of the aircraft, its mechanical components and their interaction using Dassault Systèmes CATIA computer-aided design software.
Once the JDP team had gone back to their home nations, Embraer also employed the ENOVIA vpm product development management system to organise and share design data with partners as far afield as Europe, Japan and the USA.
A $2 million virtual design centre was established in Sïo José to provide different teams of engineers and designers with a three-dimensional visual representation of the aircraft. Employing a computer to generate virtual environments on a 6 x 2.5m (20 x 8ft) display, while at the same time computing and processing three-dimensional graphics, the centre sped up processes such as verifying maintenance procedures and conducting semi-immersive design analysis.
"The biggest power is in making things visual in three-dimensional to a team of people who are designing and discussing solutions, and to look at solutions as if they were on a physical mock-up," says Satoshi Yakota, Embraer vice president industrial. "This included not only ourselves and the partners, but customers looking at access. The result was we had an extremely high level of confidence the design was right before starting to release drawings, and two years ahead of the first prototype being ready."
Since the aircraft's inception, Embraer has sought to establish a close working relationship with its launch customers and other potential operators, establishing an airline advisory board (AAB) along with a series of steering groups and man-machine interface meetings. The AAB has grown from seven airline participants in March 1999 to 27 carrier representatives at the most recent meeting.
In September 2000 the ERJ-170 moved into the critical design phase, which included collaboration with Crossair. The first metal was cut in July last year, followed within two months by the start of parts assembly. Major sub-assemblies started arriving at Sïo José earlier this year, initially with the wingbox supplied by Kawasaki Heavy Industries (KHI), followed in short succession by centre fuselage sections I and III from Latecoere and wing slats from Sonaca.
Final assembly started in July with the joining of the fuselage, including the locally produced centre section IIand nose which, after painting, were mated with the Embraer-assembled main wing in August.
The final major structural assemblies had been installed by last month, comprising the Gamesa-built empennage and KHI-supplied engine pylons, in readiness for the arrival of the first 14,200lb-thrust (63kN) General Electric CF34-8E engines. Aircraft systems were due to have been powered up for the first time bymid-October, with some testing due to be completed before rollout.
"Aircraft systems will be extensively tested prior to first flight, comprising dedicated functional and operational tests, which integrate the hydraulic, electrical and pneumatic systems with the running turbofan engine. Some critical systems such as fly-by-wire flight controls will be double checked. We'll perform approximately 500h of aircraft ground tests prior to first flight," says Affonso.
The ERJ-170 iron bird has been running since spring this year, and will have clocked up over 1,000h by the time aircraft 0001 flies. This is the first test rig of its type to be built by Embraer that integrates hydraulics, landing gear, engine thrust-reverser and cockpit. A separate CAE-built engineering development simulator is being used to define the aircraft's fly-by-wire control laws and evaluate handling characteristics.
Third in line on the ERJ-170 assembly floor behind the second flight test aircraft is the static test airframe, which will have been installed in a rig for the start of load testing by the time of rollout. Unlike earlier Embraer programmes, the static specimen will be tested to destruction at the end of a 30-month programme. Testing of a full-scale fatigue article is due to begin in the middle of next year, with the aim of taking the airframe to 240,000h - or three times the ERJ-170's planned service life.
To meet new JAA stipulations, Embraer plans to rack up 5,000 simulated flight cycles (SFC), or the equivalent of two years' operation, prior to certification, and around 20,000SFC before first delivery. It will also conduct a "barrel test", taking a fuselage section under pressure for 360,000SFC. "These figures exceed the JAA requirement of two years of operation prior to certification, and provide an excellent maturity level at entry into service," says Affonso.
Flight testing will extend over 1,800h and involve six aircraft which Embraer aims to have in the air by next April. Two will be dedicated for flying quality testing, two will be used predominantly for system testing while the remaining pair will be fully configured with seating, galleys, oxygen and lighting, and used for function and reliability testing. Embraer expects to receive Brazilian CTA certification using a single configuration of aircraft, followed by US Federal Aviation Administration approval in early 2003.
A critical flight-test objective is to validate the ERJ-170's projected field performance and steep approach capabilities needed to operate in and out of London City and Switzerland's Lugano airports. Embraer has a fall-back plan to flight test a ventral speed-brake on the ERJ-170, but is confident the aircraft will meet its short- runway guarantees equipped only with standard double-slotted flaps.
Embraer has erected a new 16,000m2 (172,000ft2) building, housing seven assembly docks, for the start of ERJ-170 series production, which is due in the second quarter of next year. The plant will produce up to eight aircraft a month, but in the prevailing financial climate, the initial rate could be cut to as few as 30 in the first year. Announced ERJ-170 orders total 82 aircraft, of which Crossair and leasing company GE Capital Aviation Services account for all but two. An order by Regional Airlines of France for 10 aircraft is on hold for now.
Embraer designed the ERJ-170 for growth, and two different stretch derivatives are in development, with a fourth version in the pipeline. The aircraft that has progressed the furthest is the ERJ-190-200, which Crossair also ordered and which is now midway through the JDP.
Embraer is aiming for 89% commonality with the ERJ-170 in terms of line-replaceable units, so it has sought to maintain the same team of partner suppliers. The 106- to 110- seat aircraft will be powered by the new 18,500lb-thrust CF34-10E engine, incorporating a wider 1.3m- (53in) diameter fan, which, in turn, will require taller main landing-gear from Liebherr.
The only major change in the partnership has been the allocation of overall design and manufacturing responsibility for the ERJ-190's larger 28.6m main wing to KHI including the winglets, making the Japanese company Embraer's largest structural supplier. KHI will maintain final assembly of the wing in Brazil at an as-yet undetermined site close to Embraer, so ensuring no major erosion in local content. This mirrors similar moves by other foreign suppliers, such as Sonaca's local subsidiary Sobraex and Liebherr's tie-up with Embraer Divisïo Equipamentos (Flight International, 16-22 October).
Trailing behind the ERJ-190-200 is the smaller -100, which had been intended as the baseline version until Crossair opted for the larger stretch. The ERJ-190-100 shares the -200's wing size, but the fuselage is 2.41m shorter, accommodating 96 to 104 passengers. Embraer is to build four ERJ-190 prototypes split equally between-100s and -200s. The larger version will fly first in mid-2003 and be delivered to Crossair in July 2004, while the ERJ-190-100 will follow a year later, though the aircraft does not have a launch order.
Another variant under study is theERJ-170-200, a smaller and much simpler 1.78m stretch of the baseline 70- to 76-seat design. The aircraft would be able to accommodate 78 to 86 passengers in a single-class configuration depending on seat pitch, and has been tailored to counter the 84-seat Bombardier CRJ900 and the wider Fairchild Dornier 728JET, which can be configured for either a four-abreast business or five abreast economy layout.
If the ERJ-170-200 is launched in the near future, as expected, its development schedule would parallel the ERJ-190-200's, and put it ahead of the ERJ-190-100.
Source: Flight International