The total output of news from the airline industry shows what regular passengers might experience. An accident is not on that list. So nothing fatal. An occasional lightning strike (se previous article) is both rare and normally unharmful, except maybe for ones ears. Bird strikes are also rare and normally no threat, thought they. might cause an engine to quit. Engine shutdowns for any other reason happens a few times a week worldwide – read almost never – and some of them might even go unnoticed to passengers if there is no need to divert. More frequent on the list is turbulence. There is a menace if seat-belts are not used. A few people have died onboard being thrown up and down. Worth noticing that the aircraft remained in good condition.
The second most common mishaps of these six mentioned here are runway excursions, where someone neglected to pave another couple of hundred feet of runway. Runways have in many places not been extended since the propeller era though the constantly heavier planes require more and more runway length. Fancy take-off- and landing weight calculations and simulator trained maneuvers compensate for that. But obviously not always. As a matter of fact a couple of times a month. None of the things mentioned above are obviously, normally, any real danger to people onboard, and there is precious little anyone can do about things – except keep seat-belts fastened.
The last and most frequent and rather disturbing trouble is smoke on board (se previous article). About every second day there is a report of an airliner in more or less distress making an unscheduled landing due to fumes. Considering the 100.000 flights a day, albeit not all airliners, it is indeed also a rare occasion, but some of those affected have needed medical attention. It is of course caused by the cabin pressurization system using bleed air from the engines, where a leak somewhere causes unhealthy cabin air. To protect oneself there are small breath devices that filters most of the harmful gases, costing less than 5 USD and occupying less space than a wallet in a bag.