The Southwest airplane accident last week has been initially attributed to a fatigue crack in a fan blade in the engine. One of the reasons that this an extremely rare event is the enormous research effort that has been expended on the design, testing and maintenance of the engines and the airframe. It’s an ongoing research effort to address the trilemma of aircraft that are safe, sustainable and low cost to build and operate. In collaboration with Strain Solutions Limited, we are in the last year of a three-year project called INSTRUCTIVE which is funded by the Clean Sky 2 programme of the European Commission [see ‘Instructive report and Brexit‘ on March 29th, 2017]. The focus of the research is the development of techniques for use in the aerospace industry to detect the initiation of cracks in the airframe before the crack is visible to the naked eye [see ‘Instructive update‘ on October 4th, 2017]. Laboratory-based techniques exist with this capability and the objective is to transfer the technology to the industrial scale and environment – initially in structural tests performed as part of the design and certification process and perhaps later as part of inspections of aircraft in service. So far, we have moved from the small components reported in the update posted in October, to a chunk of aircraft fuselage in our lab and we are preparing to participate in a test being conducted by Airbus later this year.
We are also planning a knowledge exchange workshop on ‘Real-time damage tracking in engineering structures’ on November 21st, 2018 at the University of Liverpool’s London campus. The one-day workshop is being organised in collaboration with the British Society for Strain Measurement. More details to follow – it will be free!
Image Credit: Powering the 737: CFM56-7 series | by Frans Zwart at https://www.flickr.com/photos/15545136@N06/9719995154 [CC BY-NC-ND 2.0]
One of the news reports I heard after the SW incident commented that the safety necessity is to detect an impending strain at the very microscopic level! So, it isn’t like looking for a highly visible deformation.