Now you mention it, I had indeed heard of this gas phenomenon especially messing with the instruments with its electrical charge. Would modern aircraft technology no longer be suscepitble to such gas interference, I wonder? Have the disappearances stopped or decreased? Or is the triangle avoided altogether? (I suppose that might be hard to do.) Love research: it hands us ever more questions. Answers are never as satisfying as questions but pivotal to more questions: so thank you so much for your detailed comment. (Not sure how to get to read the article through your link, though.)