Aerostructures manufacturer GKN Aerospace is working with airframer Boeing on a series of advances to enable more accurate repair of composite components and to allow otherwise invisible damage to be easily detected.
The move comes as Boeing's majority composite 787 - for which GKN supplies a number of structures and systems including the wing ice protection system and rear fan case for the Rolls-Royce Trent 1000 engines - enters service, spearheading the widespread arrival of the material into airline fleets.
Richard Oldfield, technical director at UK-based GKN, said that as the in-service fleet of 787s grows and "as people begin to learn how composites behave in the field" repair of the material will become the next big push for the MRO sector.
One advance to emerge from its work with Boeing is the use of lasers to abrade areas of composite requiring repair. The existing manual abrasion techniques, required before a repair can be carried out, do not offer the same degree of accuracy, he said. In contrast, a laser allows a technician to remove much less material.
GKN will carry out further research on the technique later this month, when a development laser arrives at its research centre on the Isle of Wight.
Oldfield believes the technique is two to three years away from maturity. Initially, it would be carried out in an authorised facility but GKN's future aspiration is to be able to perform both surface preparation and repair, including curing of composite, at remote locations, potentially even in-situ.
A further advance, said Oldfield, is to tackle the problem of invisible damage to composite structures which do not dent or deform in the same way as metal. This means both the location and the severity of an impact are difficult to check, he said.
GKN is developing a coating for composite parts that, when viewed using infra-red goggles, "will discolour a bit like a bruise" following a collision. "You can engineer the coating so it discolours differently depending on the energy level of the impact," he said.
Source: Flight International
