>> you gave me one warning, that's it. >> reporter: incidents of upset, angry, and occasionally violent passengers soared to 6,000, with 3/4 of the episodes related to mask wearing. so far this year, the numbers are down a bit. while many states are dropping mask mandates, federal authorities still require them on airplanes. and the tension is real. >> listen, you're the -- [ bleep ] >> combine that with a record number of guns at security check points, some want no fly lists for disruptive travelers, and the biden administration says they might consider it. >> you simply should not behave this way on an airplane. you shouldn't behave this way on the ground either but in air travel, it's a unique risk. >> reporter: in the meantime, many flight attendants continue training to defend themselves. other passengers and even their planes when fellow travelers for whatever reason attack.