Bombardier relies heavily on a new factory in Belfast, Northern Ireland, run by its Short Brothers subsidiary for CSeries wing production. Built with the help of £60 million ($90 million) from the UK government, the 600,000-sq-ft plant on the northwest side of Belfast City Airport’s runway specializes in new resin transfer infusion (RTI) fabrication techniques refined at other Bombardier plants in the region, in Dunmurry and Newtownabbey. Bombardier’s composite manufacturing portfolio of more than 30 components includes wings, engine nacelles, landing-gear doors, and flight control surfaces such as flaps, ailerons, elevators and rudders.
“RTI is different [from using prepreg composite sheets] as we use a dry fiber,” said Gavin Campbell, director of design engineering and technology development, during a press briefing in Belfast that coincided with the unveiling of the first nearly complete CSeries flight-test article in Montreal. “Dry fiber is more pliable and easy to handle and the resin comes in separate drums…It means we can lay down the fabric much faster and porosity is minimized.”
The resin is injected while the wing bakes in the autoclave. The one aspect of RTI that makes it really innovative, however, is that instead of using a mold of two solid halves (as in resin transfer molding) it uses “one metal tool on one side while the other half is softer, a rubber bag,” said Campbell, who further explained that the technique provides control over the process and “significant benefits” as the factory accelerates production rates.
“In the past two years we have gone from a fully configured digital mockup to a completed wing…and we have already delivered several shipsets of wings,” he noted. The plant can support more than the planned 120 shipsets a year using a pulse-line technique borrowed from the automobile industry, designed for around-the-clock production and eventually to consist of 10 jig stations for the torque box assembly. The jigs hold the assemblies vertically to make them more accessible for workers. Another advantage lies with the commonality between the CS100’s and CS300’s wings. The increased thickness of the CS300 wing accounts for the only difference, allowing for the use of common jigs.