Originally Posted by
NJRadioGuy
Their heavily-accented English was virtually impossible to understand in the usual inflight messages, but if Something Happened that required detailed instructions to passengers, that could be problematic on this route. It would be understandable when ferrying Spanish speaking passengers to and from BCN or MAD, but when serving on a route from one unilingual-English speaking nation to another, it is an issue.
I have to nitpick: flights between USA and Republic of Ireland are between unilingual and bilingual country. Of course, those Irish who have Gaelic as their first language almost certainly do understand also English.