New Patch: Extending Useful Life Of Aircraft, Increase Their Reliability And Reduce Repair Costs

Approximately 30% of the world’s fleet of commercial aircraft is more than 15 years old, with the consequent ageing of the craft structure, due to corrosion and fatigue. Given this situation, there is an inherent need to ensure navigatability and prolong their service life. Also, the introduction of new materials, such as composite materials, into the primary structures of aeroplanes – for example, the A380 and the future B787 -, has created the need to develop new, more exigent technologies that facilitate the substituting of damaged areas of the aircraft structure.

In this context of needing to depend on reliable and economically viable methodologies and technologies of repair and maintenance, the European IAPETUS 7th Framework Programme project, led by TECNALIA, arose. The project is developing a new technology for the repair of aircraft made of aluminium and of the new generation of composite materials, with the goal of it being applied in the European aeronautics industry. Thanks to this work, new, multifunctional composite materials are introduced, using carbon nanotubes, both into the matrix of the composite material as well as into the adhesive; thus achieving an easy, reliable and economically viable repair.

The nano-phase will improve the tenacity of the fracture and the fatigue of the composite. Also, it is expected that the nanotubes will confer the necessary electrical conductivity to the join between the damaged component and the patch, in order to obtain the uniform hardening of the polymer matrix: this can be produced by the polymer matrix through heating by induction or electrical resistance and which confers a conducting and sensor nature to the repair patch in order for in-service faults to be detected.

The Programme consortium is made up of a variety of centres of a multidisciplinary nature, thus all areas of the know-how necessary to assure the success of the project being covered. A total of 10 companies from France, Greece, Poland, the United Kingdom, Switzerland and Spain are represented: aeronautic structures and component manufacturers DAHER Aerospace, Hellenic Aerospace Industry and PZL-Swidnik SA); repair technologies’ equipment (GMI Aero); resins for composite materials (Hurtsman Advanced Materials), as well as a number of universities (Patras, Ioannina and Sheffield) and technological centres, (INASCO and INASMET-Tecnalia). TECNALIA’s mission, apart from project leader, will be to develop the hardening materials and techniques and those for fault detection.