Research project: "Caire"
Research area: Automation, CFRP, aviation MRO
Supported by: Federal Ministry of Economics and
  Technology (LuFoIV-3)
In collaboration with: Lufthansa Technik, Airbus Defense & Space
Start of the project: April 2012
End of project: December 2015 
Association leader: Lufthansa Technik AG
Association partner: Automation W+R
  German Aerospace Center, Braunschweig (DLR)
  Airbus Defense & Space
  Airbus Group Innovations
  Airbus Helicopters
  luratec AG
  MAPAL Dr. Kress KG
  UST Umweltsensortechnik GmbH



Due to the excellent mechanical properties combined with low weight and the prevention of corrosion, the aviation industry is seeing a growing use of fiber composite materials. In the latest generation of civil wide-body aircraft, materials such as carbon fiber reinforced plastics (CFRP) are also used in fuselage and wing structures. This requires the development and application of suitable repair procedures.

The aim of the multi-year research project CAIRE, funded by the Federal Ministry of Economics and Technology (BMWi) as part of the national aviation research program, was to develop approved, bonded structural repairs based on reliable calculations and safe manufacturing technology. This created the possibility of repairing other structural components, such as the airframe, efficiently and using the right materials.

The CAIRE technology project essentially comprised the following parts of the work:

  • The development of a repair design and analysis method with the aim of predicting the component behavior with load- or geometry-adapted shaft shapes
  • Safe, reliable and location-independent mechanical damage processing through the development of a mobile repair robot. For this purpose, the quality of the surface to be achieved is also examined and quantified
  • The development of a method for detecting various contaminants including the acceptable threshold values for bonding in order to enable reliable, reproducible repairs

In addition, the first steps to validate the repair process were taken during the project implementation in collaboration with the European Aviation Authority EASA to prepare and support later approval.

As part of the “Caire” project, the IFPT was commissioned to develop the mobile processing machine. The IFPT was responsible for the following tasks:

  • Definition of a suitable machine concept
  • Development of a system for detachable fixing the system to aircraft structures
  • Construction of a system demonstrator
  • Testing the system demonstrator in application-oriented machining scenarios
  • Development and investigation of suitable strategies to increase digitization and processing accuracies in changing assembly situations and system elasticities
  • Development of an efficient assembly and securing concept for the efficient use of the system in the field
Contact person at the institute: Dr.-Ing. Matthias Höfener