The unreasonableness of that particular politically-motivated action does not alter the fact that there is an objective concern here.
The decision to allow the use of twin-engined airliners on trans-oceanic routes (ETOPS) was predicated on strict reliability rules which dictate rigorous maintenance practices (for example, it once was, if it is not still, mandated that the same maintenance crew could not work on both engines of a given airliner, to minimize the risk of a misunderstanding or mistake compromising both engines.) This is a case of paying attention to details at the granularity of individual airplanes, and in that spirit, an unusual frequency of problems with one particular airplane warrants investigation.
The history of aviation is littered with the crashes of airplanes brought down by problems that seemed to have gone away - see the De Haviland Comet, for example.
The decision to allow the use of twin-engined airliners on trans-oceanic routes (ETOPS) was predicated on strict reliability rules which dictate rigorous maintenance practices (for example, it once was, if it is not still, mandated that the same maintenance crew could not work on both engines of a given airliner, to minimize the risk of a misunderstanding or mistake compromising both engines.) This is a case of paying attention to details at the granularity of individual airplanes, and in that spirit, an unusual frequency of problems with one particular airplane warrants investigation.
The history of aviation is littered with the crashes of airplanes brought down by problems that seemed to have gone away - see the De Haviland Comet, for example.