There was one that crashed once... here is the Air Crash Investigation episode:  https://www.youtube.com/watch?v=w6gJ1uUD5qU Disturbingly this occurred because the 'average weight' of passengers they used from the 60's was outdated, so the plane was much heavier than thought. After this crash, they raised average weight per passenger to 260 pounds, and that's what most airlines still use today. So, to answer your question, if like most airlines, the hypothetical airline is using this number, it would be at risk of crashing. edit: on a side note, planes do usually crash for multiple reasons, so the elevator cable being improperly adjusted also contributed to the crash. However, without the weight problem, the cable thing would have been fine. Makes flying with fatties even more distressing.