How common are Air Marshals on US flights? It seems almost every incident in the news results in an Air Marshal jumping in, so it makes me wonder if it's quite common? I personally never looked for the, and given they in general blend in on US flights, it's not that obvious.

Now Chinese flights are definitely quite interesting. In response to @Bub001's post, I've found that they mostly grab the first row in domestic. Most of my flights are A320/321s and occasionally A330s. I've got a domestic flight today, so I will observe again. I'm sitting in the second row of premium economy and I noticed the bulkhead seats in premium are already blocked. The last time I remember the air marshal sitting in that row. It seems like an interesting job. They do seem to help the FAs out but only half-assedly. Other times they roam around the cabin unnecessarily opening up overhead bins, shifting their belongings from the bags to their seat and in reverse.