Safety-critical spring failure in the aerospace sector
10 May 2021
In the aerospace sector, springs are everywhere. They’re in the seats and luggage bins of commercial planes, the control panels of jet fighters, and the antenna of satellites. Although there are hundreds of different spring shapes and designs flying above our heads every day, they all have something in common; they can fail.
Although a lot of springs might not be considered “safety critical” in the aerospace sector, failure – especially systemic failures – is not acceptable. Would you feel safe on a plane if there were broken components in the cabin?
This article will look at an extension spring, manufactured from stainless steel wire, which failed during fatigue testing. The spring was part of a safety-critical system used in the control panel of a plane. The end user sent several springs for fatigue testing, half of which were failing the fatigue requirements. The failures were all located in the same position, within the hook of the spring. Multiple failed samples were supplied for evidence, along with an unfractured sample for comparison.
Our standard failure analysis consists of four main stages: visual examination, optical metallography, hardness test and scanning electron microscope and EDX analysis.
Read the full article in the May issue of DPA