Single minded

BAE Systems’ single-structure carbon fibre aircraft fuselage could cut assembly costs, increase range and reduce air fatigue.

UK Aerospace engineers claim to  have produced one of the world’s most advanced aircraft structures. The group at BAE Systems’ Samlesbury production facility recently unveiled a 4:5 scale model of a Dassault Falcon business jet fuselage that has been made from a single piece of carbon fibre.

While a conventional fuselage consists of a large number of different components and fasteners, the BAE model is made from just one piece, with a few foam and carbon inserts placed in appropriate areas for additional strength.

Aerospace engineers are interested in the use of composite structural materials for a variety of reasons. Simon Baxter, a BAE engineer who worked on the project, explained: ‘Not only does a composite structure reduce assembly costs, it also makes the aircraft lighter which increases range and/or payload. In addition, there is less of a problem with fatigue as there are no metallic parts.’

Rather than using the traditional method of laying down carbon fibre plies by hand, the fuselage — jointly designed by Dassault Aviation and BAE — was manufactured by BAE using the relatively new technique of automated fibre placement. Here, a robot was used to lay individual strips of carbon fibre on to a mould. The technique is thought to result in a far higher-quality material than that produced using the traditional hand-laid fibre plies method.

BAE spokesman Paul Earnshaw said that this is the first time that the company has used the technique in the manufacture of large aerospace components.

The manufacture of the fuselage was carried out on an advanced collapsible mandrel specially developed for the project by Derbyshire-based Advanced Composites Group. The mandrel (the form around which the fibre was wound to form the structure) was specially made from carbon fibre so that it could be easily removed from the fuselage component after manufacture.

During the curing process, the mandrel and component were cured within an autoclave.

The mandrel was optimised to perform well in a vacuum as during the autoclave curing process it was sealed within a vacuum bag to keep contaminants away from the structure.

Measuring 4.5m long x 2m, the fuselage was produced as part of the £6.95m pan-European full barrel composites (FUBACOMP) programme which aims to develop European capability in fibre placement.

The structure has now been shipped to the CEAT aeronautical test centre in Toulouse, France, where it will be fitted with windshields and bulkheads and undergo a number of tests.