Bombardier doubles use of material to reduce weight

Bombardier has revealed new details about the redesigned CSeries airliner, which it still hopes to launch, possibly in 2007, revealing that it has adopted an all-composite wing for the proposed 110- to 130-seat aircraft.

The CSeries, along with the proposed CRJ900X and stretched Q400X turboprop, are being studied by Bombardier as part of efforts to revitalise its product line-up and fight off international competition for a market estimated at around 11,000 units in the 20- to 149-seat market between now and 2025.

Bombardier recently revealed it was in talks with CFM International and its joint owner General Electric, as well as Pratt & Whitney Canada, about the engine technology it requires for the airliner.

Newly revealed changes from the earlier design include a 5.6% reduction in maximum take-off weight (MTOW) for both the 110-seat C110 and 130-seat C130, and a 3.4% cut in empty weight for the C110 along with a 3.2% reduction for the C130. Other significant changes include a 3.8% block fuel reduction for the C110 on a 925km (500nm) leg, and a 1.1% cut on a 3,890km route. Reductions for the C130 on these routes would be 2.7% and 0.1% respectively.

These changes have been made possible by size and weight reduction, as well as better efficiencies promised by the engine makers, says Bombardier marketing vice-president Trung Ngo. Speaking at the Speednews corporate and regional conference, Ngo said: "We are continuing development and optimising it in all areas, the first area being the increased use of composites."

The proportion of composites in the proposed design has more than doubled from 20% to 45%, with the CSeries now featuring an all-composite wing and empennage. Previously, Bombardier said that the wing would be aluminium with composite use limited to the high lift devices.

Advanced aluminium, which formerly made up 6% of the structure, has now been dropped, with the balance split between aluminium lithium (30% versus 34% on the original), and conventional alloys and other materials (19% versus 34% on the original).

Bombardier says that, assuming a fuel price of 55¢/litre ($2.10/USgal) and a rate of 2,500 flights a year, the C110 will have up to a 17% fuel burn advantage over the Airbus A318 on a 925km route, while a C130 will have an 11% advantage over the A319 in similar conditions.




Source: Flight International