Triton FB1- 10 years of industrial lesson learnt on Computed Tomography applied to composite fan blades

In November 2015, the LEAP engine was certified and is now widely used on Airbus A320neo, Boeing 737MAX and Comac 919. During this certification process, Safran Group paid particular attention to the composites fan blades. Indeed, the introduction of this crucial part for the efficiency of the engine was faced to several challenges: the use of new technology of material - 3D woven carbon tows injected with a thermoset resin -, the production ramp-up in several plants but also the capacity to inspect it. In order to be in accordance with Design Office requirements, many different inspection methods were evaluated, and several equipment were tested before the final selection of Computed Tomography. Nevertheless, this choice was a challenge in the challenge: from a timeline point of view since the technology had to be used in production 3 years later but also from a technical point of view since CT had never been used in such industrial conditions (production rate, part overall size, number of inspectors...). An internal project was launched to be on time with this major breakthrough in the aircraft industry. After an overview of the project structuration, the presentation will highlight the work done by Safran to allow Computed Tomography to reach the industrial targets, from laboratory feasibility tests to the qualification of the inspection process. Acquisition and analysis procedures, probability of detection, dedicated software and algorithms will be discussed. The presentation will also explain how Safran ensured to have the same quality of data and results in the different plants, including during the lifetime of the CT machine. Considering the different countries and languages involved in production, the training and the qualification of the inspectors according to the international standards (NAS 410 and EN4179) will also be discussed. More than 10 years after the production starts, a global lesson learnt will be discussed.