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Systems: All the international suppliers spoke the same language when it came to systems integration

All the international suppliers spoke the same language when it came to systems integration

Every major SSJ system is being produced by an international supplier - many of which have linked with local Russian specialists. Sukhoi is reluctant to disclose the value of the content outsourced overseas, but it is without doubt the highest ever for a Russian- designed and built aircraft.

With first-tier suppliers numbering at least 10 European and North American companies, the SSJ programme's supply structure ensures that for the first time in a Russian programme, potential international customers can have peace of mind that spares and support will be available worldwide. And according to SCAC president Victor Subbotin, all the contracts with suppliers are in US dollars, which should protect Sukhoi from exchange rate fluctuations.

The first-tier suppliers have been integrated into the development effort from the beginning, and are funding their own research and development programmes for the systems they are developing for the SSJ. Many of those interviewed by Flight International acknowledge that the language and cultural differences were significant, but all managed to overcome these hurdles. "We employed interpreters with a good technical knowledge to ensure there were no misunderstandings, but it did mean the meetings tended to last a long time," says one Western supplier.

"In all our supplier contracts we have schedules agreed for building of aircraft and delivery of components to the production facilities," says Subbotin. "Inside SCAC, we have people monitoring and tracking the development progress of systems. This demands a co-ordination effort and involves visits by SCAC people to the suppliers. We will have SCAC field reps based with suppliers once production is up and running."

Europe's Liebherr Aerospace is playing a pivotal role in the SSJ, supplying two key packages -t he integrated air management and the fly-by-wire flight control (FCS) systems - both in conjunction with Russian partners. The former is being managed by Liebherr's French arm based in Toulouse, while the latter is the responsibility of its German division in Lindenberg.

Moscow office

"We have 10 people - mostly Russians - working in our Moscow office. A further 70-80 are working on the SSJ systems in our Toulouse and Lindenberg plants," says Liebherr Aerospace president Francis Niss.

The SSJ is one of several new non-Western regional airliner projects in which the company is participating. "We supply the air management system for the Antonov An-148, and for China's ACAC ARJ21 regional jet," says Niss.

Liebherr already supplies several in-production regional types such as the Embraer ERJ-145 and "is the world's number one supplier of air management systems for regional aircraft", says Niss. He adds that the SSJ FCS contract "marks the first time we have been selected to supply the total system - both primary and secondary FCS." He adds that the the SSJ's FCS is an all new design.

The FCS, which has no mechanical back-up, comprises the primary system (commanded by cockpit sidestick controllers), and secondary system, which incorporates high lift control and trimable horizontal stabiliser control systems.

Liebherr, which is collaborating with Russian company PMZ Voskhod on the FCS, supplies all the pilot cockpit controls for the FCS, including the sidestick controller hardware, in partnership with US flightdeck equipment specialist MPC.

SCAC has been working to develop the FCS's FBW control laws for two years with input from windtunnel testing and test pilots who test the feel of the aircraft on a fixed-base simulator at the Zhukovsky test centre that has been built by Russian training specialist CSTS Dinamika. The control laws will be frozen by April and then transferred to Liebherr Lindenberg to develop control software. There is still scope to tweak the laws after this point if required by late aerodynamic changes, but SCAC says it only expects this will be "fine-tuning" once the first flight has been achieved.

The brave decision to follow Airbus's lead and abandon the conventional control column was taken despite opposition from programme consultant Boeing, says Subbotin: "The sidestick saves weight and space, and it is much better from an ergonomic point of view."

Stick decision

Subbotin says that Boeing tried hard to persuade it to stay faithful to the yoke, but after "some long teleconferences with Boeing's flight safety people" SCAC "did another thing that Boeing had advised us - listen to our customers - who were unanimously in favour of the stick".

MPC's European representative Sylvere Delbecq says that although the SSJ is the first application for its patented sidestick controller design, it has been under development for a decade. "We have a unique sidestick design, as it uses minimum parts and only has one compress spring for both axes - rather than two on the Airbus stick. There is no backlash, making the feel more precise."

Chicago-based MPC - already a flightdeck controls supplier to most of the leading aircraft manufacturers - has eight engineers working full time on the SSJ cockpit controls it is developing in conjunction with Liebherr. "Everything the pilot touches will be produced by MPC," says Delbecq.

For the SSJ's air management system Liebherr is teamed with Gorky City-based Teploobmennik, which is producing 25% of the system. "We were asked to have a Russian partner and this has provided us with a good opportunity to develop our business in Russia to help reduce costs," says Ness.

Air management

The air management system comprises air conditioning, engine bleed air system, cabin pressure control system, anti-ice system, and high- and low-pressure distribution systems.

The SSJ's dual environmental control system cooling packs are installed in the fuselage forward of the wing box. "The SSJ's air management system is a conventional design," says Ness.

Liebherr uses Dassault Systems/IBM Catia V5 and Pro Engineer design software at its Toulouse and Lindenberg sites, respectively. "We have an interface between Pro Engineer and Catia V5 in Lindeberg," says Ness.

Delivery of the first Liebherr developed systems destined for the prototypes is about to begin, and Niss says that so far the programme is keeping to the deadline. "Sukhoi is really pushing to meet the schedule," he says.

Messier-Dowty was selected to supply the SSJ's entire landing gear system in late 2003, and is one of several Safran Group companies on the Russian programme - the others are nacelles specialist Aircelle and 50/50 engine partner Snecma. Messier's Toronto-based division, which is the company's centre of excellence for regional aircraft landing gear, is managing the SSJ programme in collaboration with its Vélizy headquarters plant in France. The Toronto division is handling design of the main landing gear and the landing- gear systems, while the nose gear design is being managed by Vélizy.

Production of the entire gear system is being undertaken in Toronto "although this might change when we ramp up production", says Pierre Hurpin, Messier-Dowty vice-president engineering, regional and business aircraft.

Hurpin adds that the contract covers the entire gear system - which comprises the dressed nose and main landing gear, cockpit subsystems for control and indication, emergency extension, and steering control as well as electrical harnesses, door mechanisms, actuators, uplocks, and the extension/retraction and steering systems.

Although the SSJ was originally offered with a choice of two or four-wheel main landing-gear units units, Messier-Dowty's SSJ 100 chief engineer Karl Janvier says that "Sukhoi asked us to focus on the two-wheel unit, and we completed design freeze in the fourth quarter of last year".

Subbotin says that no customer has yet selected the four-wheel design, and that although it is still available as an option, he doubts it will now be produced.

Advanced braking

Goodrich is supplying Sukhoi with an advanced braking system that includes wheels, carbon brakes and a brake-by-wire control system that shares the same features provided for much larger commercial airliners. "The brakes will incorporate one of our latest carbon materials optimised for superior wear performance and optimum torque characteristics. Coupled with an aluminium alloy wheel, the combination has been optimised for extended service life and increased maintenance intervals," says Brian Brandewie, president of Goodrich's Aircraft Wheels and Brakes division.

The braking system includes brake temperature monitoring, a feature that has historically been limited to larger aircraft. "With modern electronics, this can now be cost effective for smaller aircraft as well," adds Brandewie. Another system usually found on larger aircraft is an autobrake function that will be standard on the SSJ. The system provides selectable, automatically controlled braking during landing and rejected take-off conditions, adds the company.

Goodrich derived the Sukhoi system from other aircraft braking systems developed for test and production programmes including the Lockheed Martin F-16, Cessna Mustang and the Northrop Grumman Global Hawk and X-47B unmanned air vehicles. "The system will also include all ancillary features typically associated with aircraft antiskid systems, such as touchdown protection, locked wheel protection, gear retract braking," he adds.

The digitally based systems will allow for much more extensive information to be provided to help the troubleshooting processes, says Goodrich. "This will help minimise maintenance diagnostics by providing more detailed information to enable the proper corrective action. Also, this information is given to the flightcrew and, in case of emergency conditions, affords the best information available for informed decision-making and safe operations of the aircraft," says Brandewie. First deliveries of components are due to take place next month.

The entire cabin is the responsibility of B/E Aerospace, which designed and is producing everything from the sidewalls, ceiling and overhead bins to the lights, oxygen systems, seats and passenger service units (PSU).

"We've been responsible for everything from art to part," says Trevor Skelly, vice- president and general manager of B/E Aerospace's Flight Structures (FSI) unit.

"Sukhoi came to us and said they were looking for a Western state-of-the-art interior and we've done it," says Skelly. "We have been the integrator from nose-to-tail, and began with the industrial design. We produced the interior mock-up for the Farnborough air show, and worked with Boeing and Teague, which together acted as technical advisers to the programme."

Special features of the interior include large overhead bins that are capable of storing roller bags. "The idea is a seamless transition for passengers coming off mainline aircraft. The seats are wide as well, and the five-abreast seating in economy give it more of a bigger aircraft feel," Skelly says. "We took input from Sukhoi as to the size of the bins they wanted to accommodate, but basically this was a 'blue sky' project and it was up to us to maximise seat width and bin size." The seats are certificated to 16g standards, and the windows are "quite large", he adds.

Other B/E Aerospace-provided features include the emergency oxygen systems for both passengers and crew, the PSUs and the "full-spectrum, digital mood lighting" Skelly says. The company has also been delegated to perform several certification tests, as well as to create the certification plan and test reports. Testing will range from structural evaluation to smoke penetration and suppression, flammability and electro-magnetic interference for the lighting. Parts for the first two shipsets to equip the first pair of flight-test aircraft are currently being completed at several company sites across the UK and USA.

Honeywell shipped the first RE220(RJ) auxiliary power unit (APU) to Sukhoi in early December for use in the Russian manufacturer's compatibility test rig and flight test aircraft. The unit, which is able to start up to 37,000ft (11,300m) and operate to 41,000ft, is identical to the unit supplied to Bombardier for the CRJ700/900 and required no additional development testing for the new application, says Honeywell.

APU first

Originally developed for large corporate jets such as the Gulfstream V, the SSJ is the fifth application RE220(RJ). The engine was one of the first Western regional APUs to receive a type certificate by the Interstate Aviation Committee Avian Register, the Russian airworthiness authority. The unit is designed to deliver up to 50kg/min (110lb/min), with a simultaneous electrical load of 40kVA for main engine starting and environmental control system (ECS) operation. It will deliver 40kVA to support electrical needs up to 41,000ft, and bleed air for engine start or ECS up to 25,000ft.

The RE220[RJ] APU currently exceeds 10,000 meantime between failures in regional airline service. Parker is responsible for the aircraft's hydraulic system, including all central hydraulic and distribution system components, pumps, reservoirs, filters, accumulators, valves, quick disconnects, tubing, fittings, brackets, fasteners, and an electronic control unit with its associated software. The company is also poised to sign a contract covering the development of the on-board inert gas generating system (OBIGGS) for the aircraft, having positioned itself for the production of a smaller system since 2005. Parker is teamed with Honeywell on the development of a series of OBIGGS systems for the Boeing 7-series aircraft.

Patrick Conner, programme manager for Parker's Sukhoi project, says the design of the hydraulic system is based on "a lot of experience in this size area with aircraft like the Embraer 170/190 and Bombardier CRJ700." The 207bar (3,000lb/in2) system is subdivided into three independent systems, each with its own "boot-strap" reservoir, adds Parker's SSJ systems manager Simon Mulholland. "This reflects Sukhoi's desire to have a very proven design." As part of its responsibilities, Parker has also set up a hydraulic test rig that includes production-standard components covering "everything right down to the filters, and will include running endurance tests and flight scenarios", Mulholland adds.

Unusual aspects of the design include a unique seal arrangement to prevent any possibilities of gas leaks from the reservoirs and accumulators, and adaptations to allow the accumulators to continue to keep up pressures in the system even while parked for several hours at temperatures as low as -65°C (-85°F). "They just wanted it to be a better system, but it's been hard to accommodate for the temperature range," adds Mulholland.

"We started to test the first production hardware in Germany at our Wiesbaden site in January," says Conner.




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