After a succession of disappointments, Bombardier revealed good news at Paris about the CSeries

It was with some excitement, and not a little relief, that Bombardier revealed at Le Bourget that it was “engaged” with Pratt & Whitney Canada on development of a new centerline engine to power its CSeries airliner family.

Bombardier CSeries

Bombardier is budgeting $2 billion to build this family of 110- to 140-seat mainline airliners, and the P&WC talks represent vital progress in the development of the CSeries.

A new engine is central to Bombardier’s concept for its new model, as it is promising the CSeries will offer 15% lower cash operating costs (which exclude capital costs) than today’s aircraft, much of this to be achieved through a powerplant providing better fuel consumption, simpler design, lower maintenance costs and improved reliability.

Since the formal unveiling of the CSeries almost a year ago at Farnborough, Bombardier’s search for a powerplant has seen it target several potential brides for a trip up the aisle. But when talks with International Aero Engines ended recently, the airframer faced the unenviable prospect of building the world’s first 110-seat glider. “Bombardier is offering a very nice little airliner,” a senior executive from a major European regional airline told Flight International recently. “The trouble is, the engine will be the major determinant of the key advantages they are promising – lower fuel burn, maintenance and operating costs – and they haven’t got one yet.”

With the pressure on Bombardier’s new commercial aircraft programme president Gary Scott to secure an engine supplier for the CSeries, he admitted at Paris there was “a lot of temptation along the way” to compromise the design to get a powerplant. But Bombardier has stuck to its guns and is now in talks about powering the aircraft with an all-new design.

“We’ve been engaged with P&WC about a solution for a few weeks – we could not engage with them while talks were ongoing with [Pratt & Whitney joint venture] IAE,” Scott said at the show. He added that talks have progressed “very rapidly”, although he cautioned that it will “take a while to complete an agreement”.

Scott expects the programme to be launched in the third quarter, by which time there should be an agreement on the powerplant, although “it’s not absolutely necessary”. He added that “launch commitments should be in place by then”.

Bombardier’s vision for the engine that P&WC will produce is that it will have 10% lower specific fuel consumption than current designs. With a thrust rating in the 21,000-23,000lb (93-102kN) band, the engine will feature innovations such as variable-frequency generators instead of integrated drive generators, to provide lower maintenance. An average time on wing of 18,000 cycles is being targeted, with mature reliability levels being the goal from entry into service – in other words a dispatch interruption rate of 0.14% and mission interruption rate of 0.003% from the start.

Despite the extended time it has taken to get close to an agreement with an engine supplier, and the need for an all-new powerplant to be developed, John Holding, Bombardier’s vice-president of integrated product definition, new commercial aircraft programme, is confident the target of delivering the first aircraft before the end of 2010 can be achieved. “We’ve always planned to have a new engine for this aircraft, so whether it was P&WC or someone else, it shouldn’t make any difference,” he said.

According to Holding, new technology in the CSeries structure will bring a number of advantages. “There will be reduced parts count, and an optimised selection of advanced materials,” he said.

As the diagram on P31 shows, the bulk of the wing and fuselage structure will be aluminium and advanced aluminium, although composites will account for a quarter of the aircraft’s structure – a similar level to the Airbus A380. Composites will be used for the rear fuselage section, fin and tailplane as well as the wing trailing-edge and belly fairing. Structural weight savings amount to more than 10%, says Bombardier.

The CSeries will have fly-by-wire flight controls, enabling the size of empennage to be reduced as the aircraft will not require the same level of natural aerodynamic stability as a design with conventional controls. It will also feature wing load alleviation during manoeuvring.

Preferred supplier

The definition of the flightdeck is well advanced, although Bombardier is yet to sign a formal agreement with its “preferred supplier” Rockwell Collins for the avionics, which could leave the door open to rival Thales. The flightdeck will incorporate four large landscape displays – one in front of each pilot providing primary flight and navigation information and two central screens – as well as a large electronic flightbag display for each crew member. Sidestick controllers will be used.

So Bombardier’s plans for the new twinjet are at last heading in the right direction, but there are still significant hurdles to clear before the programme can secure a formal go-ahead, not least of which is the signing of a firm agreement with P&WC for an engine, and finding some launch customers.



Source: Flight International