This finding is an artifact of their methodology. Southwest is not EU admitted because they only recently expanded to routes outside of the US and have not so f

This finding is an artifact of their methodology. Southwest is not EU admitted because they only recently expanded to routes outside of the US and have not so far expanded outside of the Americas (they may not want to as it would introduce real complications to unified-fleet their business model). They are not fatality-free in the last ten years, but their fatality in 2018 was the only passenger fatality they have ever experienced. This incident also seemed fairly fault-free on the part of Southwest as it resulted in guidance changes requiring more frequent inspection of the engine model involved than previously. Perhaps they should undergo IOSA audit, but it is entirely optional and is viewed as less necessary in the US because the FAA's mandatory safety oversight is similarly strict. It is mostly a certification obtained by airlines to demonstrate that they are "as safe" as their peers, and as the largest carrier in the US with an excellent safety record, Southwest is probably just not very inclined to go to the extra expense for a certificate to hang on the wall. I would say this is a basic problem with evaluating airline safety based on external accreditation rather than on their actual safety record. However, I'm sure the latter would be much more difficult to do globally.